US20150033636A1

US20150033636A1 - Abrasive article and method of forming same

Info

Publication number: US20150033636A1
Application number: US14/449,659
Authority: US
Inventors: Lingyu Li; Muthu Jeevanantham; Sena Ada; Scott Leonard
Original assignee: Saint Gobain Abrasifs SA; Saint Gobain Abrasives Inc
Current assignee: Saint Gobain Abrasifs SA; Saint Gobain Abrasives Inc
Priority date: 2013-08-01
Filing date: 2014-08-01
Publication date: 2015-02-05

Abstract

An abrasive article may be configured to work titanium and may comprise a body including a bond material comprising an organic material. A first type of abrasive particles may be contained within the bond material and comprise fused alumina. The body may comprise a burnout modulus of rupture (MOR) of at least about 1.6 MPa.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority from U.S. Provisional Patent Application No. 61/861,076, filed Aug. 1, 2013, entitled “ABRASIVE ARTICLE AND METHOD OF FORMING SAME,” naming inventor Lingyu Li et al., which application is incorporated by reference herein in its entirety.

BACKGROUND

1. Field of the Disclosure
The following is directed to abrasive articles, and particularly, bonded abrasive articles comprising abrasive particles of one or more particular types.
2. Description of the Related Art
Abrasive wheels are typically used for cutting, abrading, and shaping of various materials, such as stone, metal, glass, plastics, among other materials. Generally, the abrasive wheels can have various phases of materials including abrasive grains, a bonding agent, and some porosity. Depending upon the intended application, the abrasive wheel can have various designs and configurations. For example, for applications directed to the finishing and cutting of metals, some abrasive wheels are fashioned such that they have a particularly thin profile for efficient cutting.
However, given the application of such wheels, the abrasive articles are subject to fatigue and failure. In fact, the wheels may have a limited time of use of less than a day depending upon the frequency of use. Accordingly, the industry continues to demand abrasive wheels capable of improved performance.

SUMMARY

An embodiment of an abrasive article may be configured to work titanium and may comprise a body including a bond material. A first type of abrasive particles may be contained within the bond material and comprise fused alumina. A second type of abrasive particles may be contained within the bond material and comprise fused zirconia.
In some embodiments, a method of working titanium may include providing a workpiece comprising titanium. The method may further include moving a bonded abrasive body relative to the workpiece to conduct a material removal process on the workpiece, wherein the bonded abrasive body comprises a relative material removal rate (MRR) improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article.
An abrasive article may be configured to work titanium and include a body having a bond material comprising an organic material. A first type of abrasive particles may be contained within the bond material comprising fused alumina. In addition, the body may include a burnout elastic modulus (EMOD) of at least about 250 MPa.
In still another embodiment, an abrasive article configured to work titanium may comprise a body including a bond material comprising an organic material. A first type of abrasive particles may be contained within the bond material comprising fused alumina. The body may comprise a burnout modulus of rupture (MOR) of at least about 1.6 MPa.
In an alternate embodiment, an abrasive article configured to work titanium may comprise a body including a bond material comprising a resin having a high temperature flexure modulus of at least 1.05. A first type of abrasive particle may be contained within the bond material and may comprise fused alumina.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

FIG. 1 includes a plot of relative performance versus content of a particular type of abrasive particle for the three specific conventional samples and specific samples representative of embodiments herein.

FIG. 2 includes a plot of relative material removal rate versus content of a particular type of abrasive particle for three specific conventional samples and specific samples representative of embodiments herein.

FIG. 3 includes a plot comparing the grain crush strength of an alumina abrasive article to that of a zirconia abrasive article.

The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION

The following is directed to abrasive tools having abrasive particles contained within a bond material for finishing, shaping, and/or conditioning workpieces. Certain embodiments herein are directed to bonded abrasive wheels, including large-diameter snagging wheels, that may be used for shaping of metal workpieces, including metals of titanium or stainless steel. However, the features of the embodiments herein may be applicable to other abrasive technologies, including for example, coated abrasives and the like.
The abrasive article can be formed by forming a mixture of components or precursor components that may be part of the final abrasive article. For example, the mixture can include components of the final abrasive article, such as abrasive particles, bond material, filler, and a combination thereof. In one embodiment, the mixture can include a first type of abrasive particle. A type of abrasive particle can be defined by at least a composition, a mechanical property (e.g., hardness, friability, etc.), particle size, a method of making, and a combination thereof.
According to one embodiment, the first type of abrasive particles can include an oxide, and particularly, aluminum. For example, the first type of abrasive particles can include alumina. In one particular instance, the first type abrasive particles can include fused alumina. In another instance, the first type abrasive particles can consist essentially of fused alumina. An exemplary type of fused alumina can include fused alumina 57A, commercially available from Washington Mills.
Regarding absolute values for single grain crush strength, the force (in Newtons) required to break the grains may be given in terms of the percentage of the grains broken when subjected to breaking force. For example, about 220 N to about 280 N may be required to break 50% of the first type of abrasive particle. Thus, to break 50% of the first type of abrasive particles at least about 220 N is required. Alternatively, at least about 230 N, at least about 240 N, or even at least about 250 N is required to break 50% of the first type of abrasive particles. In still other examples, no greater than about 1500 N is required to break 50% of the first type of abrasive particles. Alternatively, no greater than about 1000 N, or even no greater than about 500 N may be required to break 50% of the first type of abrasive particles. It will be appreciated that the first type of abrasive particle can have an absolute crush strength within a range between any of the above noted minimum and maximum values. In these examples, the first type of abrasive particles had an average size of about 6 grit.
In order to break 90% of the first type of abrasive particle about 300 N to about 400 N of force may be required. Thus, to break 90% of the first type of abrasive particles, at least about 300 N, at least about 325 N, at least about 350 N, or no greater than about 2000 N, no greater than about 1500 N, no greater than about 1000 N, no greater than about 500 N may be required. It will be appreciated that the first type of abrasive particle can have an absolute crush strength within a range between any of the above noted minimum and maximum values.
In terms of hardness, the first type of abrasive particle may have a hardness. For example, the first type of abrasive particle may have a hardness of at least about 15.7 GPa, at least about 16 GPa, at least about 16.5 GPa, or no greater than about 19 GPa, no greater than about 18.5 GPa, no greater than about 18 GPa, no greater than about 17.5 GPa. It will be appreciated that the first type of abrasive particle can have a hardness within a range between any of the above noted minimum and maximum values. For example, the first type of abrasive particle may have a hardness in a range of about 16.52 GPa to about 17.46 GPa.
According to one embodiment, the first type of abrasive particle can have an average particle size of at least about 200 microns, such as at least about 400 microns, at least about 600 microns, at least about 800 microns, at least about 1000 microns, at least about 1500 microns, at least about 2000 microns, at least about 2500 microns, at least about 3000 microns, or even at least about 4000 microns. Still, in another non-limiting embodiment, the first type of abrasive particle can have an average particle size of not greater than about 3000 microns, such as not greater than about 2500 microns, not greater than about 2000 microns, not greater than about 1500 microns, or even not greater than about 1000 microns. It will be appreciated, that the average particle size may be determined by measuring and averaging the longest dimension (i.e., the length) of the particles as viewed in two-dimensions (e.g., SEM). The first type of abrasive particle can have an average particle size within a range between any of the minimum and maximum values noted above. For example, the first type of abrasive particle may have a median particle size in a range of about 200 microns to about 5000 microns (e.g., about 4 U.S. mesh to about 60 U.S. mesh).
The first type of abrasive particle can be made of crystalline grains. In particular instances, the first type of abrasive particle can have a median grain size of about 4 U.S. mesh to about 60 U.S. mesh (e.g., about 200 microns to about 5000 microns).
The abrasive particles of the mixture and the final-formed abrasive article may include more than one type of abrasive particle. For example, the mixture can include a second type of abrasive particle different than the first type of abrasive particle. The second type of abrasive particle can differ from the first type of abrasive particle by any one of a composition, a mechanical property (e.g., hardness, friability, etc.), particle size, a method of making, or a combination thereof.
According to one embodiment, the second type of abrasive particle can have a different average particle size as compared to an average particle size of the first type of abrasive particle. For example, the second type of abrasive particle can have an average particle size that is greater than the average particle size of the first type of abrasive particle. Still, in another embodiment, the second type of abrasive particle can have an average particle size that is less than the average particle size of the first type of abrasive particle.
In contrast to the first type of abrasive particle, about 1800 N to about 2100 N may be required to break 50% of the second type of abrasive grains. Thus, to break 50% of the second type of abrasive particles, at least about 300 N, at least about 500 N, at least about 1000 N, or no greater than about 2400 N, no greater than about 2300 N, no greater than about 220 N may be required. It will be appreciated that the second type of abrasive particle can have an absolute crush strength within a range between any of the above noted minimum and maximum values.
In order to break 90% of the second type of abrasive particles about 2300 N to about 2900 N of force may be required. Thus, to break 90% of the second type of abrasive particles, at least about 500 N, at least about 1000 N, at least about 1500 N, at least about 2000 N, or no greater than about 3300 N, no greater than about 3200 N, no greater than about 3100 N, no greater than about 3000 N may be required. It will be appreciated that the second type of abrasive particle can have an absolute crush strength within a range between any of the above noted minimum and maximum values.
Relative friability between the first and second types of abrasive particles may be defined as follows:
[(N _G2 −N _G1)/N _G1]×100%
wherein N_G1is the amount of force (e.g., in newtons) required to break a single grain of a first type of abrasive particle and N_G2is the amount of force required to break a single grain of a second type of abrasive particle. These forces may be derived from, for example, a Weibull probability plot of grain crush strength, such as the one disclosed in FIG. 3.
In some embodiments, the first type of abrasive particle is at least about 50% more friable than the second type of abrasive particle. In other embodiments, the first type of abrasive particle may be about 60% more friable than the second type of abrasive particle, about 70% more friable, about 80% more friable, about 90% more friable than the second type of abrasive particle. In still other embodiments, the first type of abrasive particle is not greater than 200% more friable than the first type of abrasive particle. For example, the first type of abrasive particle may be not greater than 150% more friable than the second type of abrasive particle, not greater than 125%, not greater than 100%, not greater than 98%, not greater than 96%, or even not greater than 94% than the second type of abrasive particle. It will be appreciated that the abrasive particle may have a friability within a range between any of the above noted minimum and maximum percentages.
In terms of hardness, the second type of abrasive particle may have a hardness of at least about 14 GPa, at least about 14.25 GPa, at least about 14.5 GPa, or no greater than about 16.5 GPa, no greater than about 16.25 GPa, no greater than about 16 GPa, no greater than about 15.75 GPa. It will be appreciated that the second type of abrasive particle can have a hardness within a range between any of the above noted minimum and maximum values. For example, the second type of abrasive particle may have a hardness in a range of about 14.79 GPa to about 15.65 GPa.
Relative hardness between the first and second types of abrasive particles may be defined as follows:
[(H _G1 −H _G2)/H _G2]×100%
wherein H_G1is the hardness of a first type of abrasive particle and H_G2is the hardness of a second type of abrasive particle. In some embodiments, the first type of abrasive particle may be about 1% harder than the second type of abrasive particle, about 3% harder, about 5% harder, about 10% harder than the second type of abrasive particle. In still other embodiments, the first type of abrasive particle is not greater than 30% harder than the first type of abrasive particle. For example, the first type of abrasive particle may be not greater than 25% harder than the second type of abrasive particle, not greater than 20%, not greater than 18%, or even not greater than 16% harder than the second type of abrasive particle. It will be appreciated that the abrasive particles may have a hardness within a range between any of the above noted minimum and maximum percentages.
In certain instances, the second type of abrasive particle can have an average particle size of at least about 200 microns, such as at least about 400 microns, at least about 600 microns, at least about 800 microns, at least about 1000 microns, at least about 1500 microns, at least about 2000 microns, at least about 2500 microns, at least about 3000 microns, or even at least about 4000 microns. Still, in another non-limiting embodiment, the second type of abrasive particle can have an average particle size of not greater than about 3000 microns, such as not greater than about 2500 microns, not greater than about 2000 microns, not greater than about 1500 microns, or even not greater than about 1000 microns. The second type of abrasive particle can have an average particle size within a range between any of the minimum and maximum values noted above. For example, the second type of abrasive particle may have a median particle size in a range of about 200 microns to about 5000 microns (e.g., about 4 U.S. mesh to about 60 U.S. mesh).
According to an embodiment, the second type of abrasive particle can include an oxide, and particularly, an oxide such as alumina, zirconia, and a combination thereof. In at least one embodiment, the second type of abrasive particle can consist essentially of zirconia and alumina. For certain instances, the second type of abrasive particle can include alumina and zirconia, and can have a greater content of alumina as compared to a content of zirconia. For example, the second type of abrasive particle can contain a majority content of alumina and a minority content of zirconia. In one exemplary embodiment, the second type of abrasive particle can include an alumina-zirconia composite particle comprising approximately 75% alumina and 25% zirconia, commercially available as ZF/ZS grains from Saint-Gobain Grains and Powders. More particularly, the second type of abrasive particle can consist essentially of an alumina-zirconia abrasive particle.
According to one particular embodiment, the second type of abrasive particle can include at least about 60% alumina for the total composition of the abrasive particle. Moreover, in certain other instances, the content of alumina can be greater, such as at least about 70%, and even at least about 75%. Still, in another non-limiting embodiment, the amount of alumina present in the second type of abrasive particle can be not greater than about 98%, such as not greater than about 95%, not greater than about 90%, or even not greater than about 85%. The second type of abrasive particle can have an alumina content within a range between any of the minimum and maximum percentages noted above.
The second type of abrasive particle may contain a particular content of zirconia. For example, the second type of abrasive particle can include at least about 5% zirconia, such as at least about 10% zirconia, or even at least about 15% zirconia for the total content of components make up the composition of the abrasive particle. Still, in another non-limiting embodiment, the amount of zirconia present in the second type of abrasive particle can be not greater than about 40% zirconia, such as not greater than about 35% zirconia, not greater than about 30% zirconia, or even not greater than about 25% zirconia. The second type of abrasive particle can have a zirconia content within a range between any of the minimum and maximum percentages noted above.
The mixture and the body of the finally formed abrasive article may comprise a certain blend of the first type of abrasive particle and a second type of abrasive particle. For example, the blend can include a different amount (vol %) of the first type of abrasive particle than an amount (vol %) of the second type of abrasive particle as measured by the weight of the mixture or the weight of the body of the abrasive article. In certain cases, the blend can include a greater amount of the first type of abrasive particles than the amount of the second type of abrasive particles.
In one instance, the blend may be defined by a ratio (AP1/AP2) of at least about 0.01, wherein AP1 represents an amount of first type of abrasive particles in the blend and AP2 represents an amount of the second type of abrasive particles in the blend. The amount may be measured as the weight or weight percent of each of the respective types of abrasive particle. In one embodiment, the ratio (AP1/AP2) may be at least about 0.05, such as at least about 0.08, at least about 0.1, at least about 0.12, at least about 0.14, or even at least about 0.16. Still, in one other non-limiting embodiment, the ratio (AP1/AP2) may be not greater than about 4, such as not greater than about 3, such as not greater than about 2, not greater than about 1.5, not greater than about 1, not greater than about 0.9, not greater than about 0.7, not greater than about 0.6, not greater than about 0.5, or even not greater than about 0.4. The ratio can be within a range between any of the minimum and maximum values noted above.
The abrasive particles of any type may have an elongated shaped. In a particular instance, the abrasive particles may have an aspect ratio, defined as a ratio of the length:width, of at least about 2:1, wherein the length is the longest dimension of the particle and the width is the second longest dimension of the particle (or diameter) perpendicular to the dimension of the length as viewed in two dimensions. In other embodiments, the aspect ratio of the abrasive particles can be at least about 2.5:1, such as at least about 3:1, at least about 4:1, at least about 5:1, or even at least about 10:1. In one non-limiting embodiment, the abrasive particles may have an aspect ratio of not greater than about 5000:1. Still, it will be appreciated, that in other embodiments, the abrasive particles of any type can be generally equiaxed having an aspect ratio of substantially 1:1. In yet another embodiment, the abrasive particles of any type can have an irregular shape.
In at least one embodiment, the abrasive particles (of any type) can have a particular cross-sectional shape as viewed in two dimensions. For example, the abrasive particles can have an ellipsoidal cross-sectional shape. An ellipsoidal shape can include circles, ellipses, and any other curvilinear shapes. Alternatively, in other instances, the abrasive particles can have a polygonal cross-sectional shape. Some suitable, non-limiting, examples of polygonal cross-sectional shapes include triangular, rectangular, pentagonal, hexagonal, heptagonal, octagonal, and the like.
As described herein, in addition to the abrasive particles, the mixture may also include other components or precursors to facilitate formation of the abrasive article. For example, the mixture may include abrasive particles and a bond material. According to one embodiment, the bond material may include a material selected from the group consisting of an organic material, an organic precursor material, an inorganic material, an inorganic precursor material, a natural material, and a combination thereof. In particular instances, the bond material may include a metal or metal alloy, such as a powder metal material, or a precursor to a metal material, suitable for formation of a metal bond matrix material during further processing.
According to another embodiment, the mixture may include a vitreous material, or a precursor of a vitreous material, suitable for formation of a vitreous bond material during further processing. For example, the mixture may include a vitreous material in the form of a powder, including for example, an oxygen-containing material, an oxide compound or complex, a frit, and any combination thereof.
In yet another embodiment, the mixture may include a ceramic material, or a precursor of a ceramic material, suitable for formation of a ceramic bond material during further processing. For example, the mixture may include a ceramic material in the form of a powder, including for example, an oxygen-containing material, an oxide compound or complex, and any combination thereof.
According to another embodiment, the mixture may include an organic material, or a precursor of an organic material, suitable for formation of an organic bond material during further processing. Such an organic material may include one or more natural organic materials, synthetic organic materials, and a combination thereof. In particular instances, the organic material can be made of a resin, which may include a thermoset, a thermoplastic, and a combination thereof. According to one embodiment, the bond material can include an organic material selected from the group of epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins, and a combination thereof. In one particular case, the bond can consist essentially of a resin. Some suitable resins can include phenolics, epoxies, polyesters, cyanate esters, shellacs, polyurethanes, rubber, and a combination thereof. In one particular embodiment, the mixture includes an uncured resin material configured to form a phenolic resin bond material through further processing.
Other materials, such as a filler, can be included in the mixture. The filler may or may not be present in the finally-formed abrasive article. The filler may include a material selected from the group consisting of powders, granules, spheres, fibers, and a combination thereof. Moreover, in particular instances, the filler can include an inorganic material, an organic material, and a combination thereof. In a certain embodiment, the filler can include a material such as sand, bubble alumina, bauxite, chromites, magnesite, dolomites, bubble mullite, borides, titanium dioxide, carbon products (e.g., carbon black, coke or graphite), silicon carbide, wood flour, clay, talc, hexagonal boron nitride, molybdenum disulfide, feldspar, nepheline syenite, glass spheres, glass fibers, CaF2, KBF4, Cryolite (Na₃AlF₆), potassium Cryolite (K₃AlF₆), pyrites, ZnS, copper sulfide, mineral oil, fluorides, carbonates, calcium carbonate, and a combination thereof, wherein the filler comprises a material selected from the group consisting of an antistatic agent, a lubricant, a porosity inducer, coloring agent, and a combination thereof. In particular instances wherein the filler is particulate material, it may be distinct from the abrasive particles, being significantly smaller in average particle size than the abrasive particles of any type.
After forming the mixture, the process of forming the abrasive article can further include forming a green body comprising abrasive particles contained in a bond material. A green body is a body that is unfinished and may undergo further processing before a finally-formed abrasive article is formed. Forming of the green body can include techniques such as pressing, molding, casting, printing, spraying, and a combination thereof. In one particular embodiment, forming of the green body can include pressing the mixture into a particular shape, including for example, conducting a cold isostatic pressing operation to form a green body in the desired form of the body.
After forming the green body, the process can continue by treating the green body to form a finally-formed abrasive article comprising a body. Some suitable examples of treating can include curing, heating, sintering, crystallizing, polymerization, pressing, and a combination thereof. In one example, the process may include bond batching, mixing abrasive with bond, filling a mold, pressing, wheel baking or curing, finishing, inspection, speed testing, and packing and shipping
The abrasive articles of the embodiments herein can have a body that may be in the form of a bonded abrasive. The body can have various shapes, including for example, a hone, a cone, a cup, flanged shapes, a cylinder, a wheel, a ring, and a combination thereof. In one particular embodiment, the body can be a bonded abrasive snagging wheel.
After treating, the abrasive article can be formed to have a body including a particular content of bond material. For example, the body can have at least about 25 vol % bond material for the total volume of the body. In other instances, the content of bond material in the body can be greater, such as at least about 30 wt %, at least about 35 wt %, at least about 40 wt %, at least about 45 vol %, at least about 50 vol %, at least about 55 vol %, or even at least about 60 vol %. Still, in at least one non-limiting embodiment, the content of bond material in the body can be not greater than about 70 vol %, such as not greater than about 65 vol %, not greater than about 60 vol %, not greater than about 55 vol %, not greater than about 50 vol %, not greater than about 45 vol %, not greater than about 40 vol %, not greater than about 35 vol %, or even not greater than about 30 vol %. It will be appreciated that the content of bond material in the body can be within a range between any of the minimum and maximum percentages noted above.
According to one embodiment, the bond material of the body can include a resin, and particularly a phenolic resin. In some embodiments, the resin may have a high temperature flexure modulus of at least 1.05. Alternatively, the resin may have an increasing high temperature flexural modulus. The phenolic resin may be modified with a curing or cross-linking agent, such as hexamethylene tetramine. At temperatures in excess of about 90° C., some examples of the hexamethylene tetramine may form crosslinks to form methylene and dimethylene amino bridges that help cure the resin. The hexamethylene tetramine may be uniformly dispersed within the resin. More particularly, hexamethylene tetramine may be uniformly dispersed within resin regions as a cross-linking agent. Even more particularly, the phenolic resin may contain resin regions with cross-linked domains having a sub-micron average size.
According to one embodiment, the body can have a particular content of porosity. For example, the body can have not greater than about 10 vol % porosity for the total volume of the body. In a particular instance, the body can have not greater than about 9 vol %, such as not greater than about 8 vol %, not greater than about 7 vol %, not greater than about 6 vol %, not greater than about 5 vol %, not greater than about 4 vol %, not greater than about 3 vol %, or even not greater than about 2 vol %. According to one non-limiting embodiment, the body can have zero porosity, or at least about 0.05 vol % porosity. In certain other instances, the body can have a porosity of at least about 0.5 vol %, at least about 1 vol %, at least about 2 vol %, at least about 3 vol %, at least about 4 vol %, at least about 5 vol %, at least about 6 vol %, at least about 7 vol %, or even at least about 8 vol %. It will be appreciated that the porosity of the body can be within a range between any of the minimum and maximum percentages noted above.
For certain abrasive articles of the embodiments herein, the body can have a particular total content of abrasive particles, which includes the total amount of all types of abrasive particles. For example, in one embodiment, the body can include at least about 30 vol % abrasive particles for the total volume of the body. In another embodiment, the body can have at least about 35 vol %, at least about 40 vol %, at least about 45 vol %, at least about 50 vol %, at least about 55 vol %, at least about 60 vol %, at least about 65 vol %, or even at least about 70 vol % abrasive particles. In at least one non-limiting embodiment, the body can have a content of abrasive particles of not greater than about 75 vol %, such as not greater than about 70 vol %, not greater than about 65 vol %, not greater than about 60 vol %, not greater than about 50 vol %, not greater than about 45 vol %, not greater than about 40 vol %, or even not greater than about 35 vol %. It will be appreciated that the total content of abrasive particles in the body can be within a range between any of the minimum and maximum percentages noted above.
Moreover, the body of the abrasive article may have a particular content of the first type of abrasive particle. For example, in one embodiment, the body can include at least about 1 vol % of the first type of abrasive particle for the total volume of the body. In another embodiment, the body can have at least about 5 vol %, at least about 10 vol %, at least about 15 vol %, at least about 20 vol %, at least about 25 vol %, at least about 30 vol %, at least about 35 vol %, at least about 40 vol %, or even at least about 45 vol % of the first type of abrasive particle. In at least one non-limiting embodiment, the body can have a content of the first type of abrasive particle of not greater than about 50 vol %, such as not greater than about 45 vol %, not greater than about 40 vol %, not greater than about 35 vol %, not greater than about 30 vol %, not greater than about 25 vol %, not greater than about 20 vol %, not greater than about 15 vol %, not greater than about 10 vol %, not greater than about 5 vol %, or even not greater than about 2 vol %. It will be appreciated that the total content of the first type of abrasive particle in the body can be within a range between any of the minimum and maximum percentages noted above.
The body of the abrasive article may have a particular content of the second type of abrasive particle. For example, in one embodiment, the body can include at least about 1 vol % of the first type of abrasive particle for the total volume of the body. In another embodiment, the body can have at least about 5 vol %, at least about 10 vol %, at least about 15 vol %, at least about 20 vol %, at least about 25 vol %, at least about 30 vol %, at least about 35 vol %, at least about 40 vol %, or even at least about 45 vol % of the first type of abrasive particle. In at least one non-limiting embodiment, the body can have a content of the second type of abrasive particle of not greater than about 50 vol %, such as not greater than about 45 vol %, not greater than about 40 vol %, not greater than about 35 vol %, not greater than about 30 vol %, not greater than about 25 vol %, not greater than about 20 vol %, not greater than about 15 vol %, not greater than about 10 vol %, not greater than about 5 vol %, or even not greater than about 2 vol %. It will be appreciated that the total content of the second type of abrasive particle in the body can be within a range between any of the minimum and maximum percentages noted above.
According to one embodiment, the abrasive article may be particularly suited for grinding and conditioning of workpieces, which may include processes such as cutting, grinding, finishing, and a combination thereof. Certain suitable workpieces can include inorganic materials, and more particularly workpieces made of a metal or metal alloy. According to one embodiment, the abrasive article may be particularly suited to grind materials such as titanium or steel.
In an embodiment, the body can have a particular burnout modulus of rupture (MOR). The burnout procedure included placing three bars per sample (or specification) in an oven once the oven reached 450° C. Each bar measured 1″×0.5″×5″. The samples were burned at 450° C. for 4 hours and then allowed to cool inside the oven. The measurements were taken at room temperature conditions. According to one aspect, the body can have a burnout MOR of at least about 1.6 MPa. In still other instances, the burnout MOR can be at least about 1.7 MPa, such as at least about 1.8 MPa, at least about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, or even at least about 2.2 MPa. In one non-limiting embodiment, the burnout MOR can be not greater than about 10 MPa, such as not greater than about 8 MPa. It will be appreciated that the burnout MOR of the body can be within a range between any of the minimum and maximum values noted above.
According to another aspect, the body can have a particular burnout elastic modulus (EMOD). The burnout procedure included placing three bars per sample (or specification) in an oven once the oven reached 450° C. Each bar measured 1″×0.5″×5″. The samples were burned at 450° C. for 4 hours and then allowed to cool inside the oven. The measurements were taken at room temperature conditions. According to one aspect, the body can have a burnout EMOD of at least about 250 MPa. In still other instances, the burnout EMOD can be at least about 270 MPa, at least about 300 MPa, at least about 325 MPa, at least about 350 MPa, at least about 375 MPa, at least about 400 MPa, at least about 425 MPa, or even at least about 450 MPa. In one non-limiting embodiment, the burnout EMOD can be not greater than about 1000 MPa, such not greater than about 800 MPa. It will be appreciated that the burnout EMOD of the body can be within a range between any of the minimum and maximum values noted above.
Items
Item 1. An abrasive article configured to work titanium comprising: a body including: a bond material comprising a resin having a high temperature flexure modulus of at least 1.05; and a first type of abrasive particles contained within the bond material comprising fused alumina.
Item 2. The abrasive article of item 1, wherein the first type abrasive particles consist essentially of fused alumina.
Item 3. The abrasive article of item 1, wherein the first type of abrasive particle comprises an average particle size of at least about 200 microns, at least about 400 microns, at least about 600 microns, at least about 800 microns, at least about 1000 microns, at least about 1500 microns, at least about 2000 microns, at least about 2500 microns, at least about 3000 microns, at least about 4000 microns, not greater than about 3000 microns, not greater than about 2500 microns, not greater than about 2000 microns, not greater than about 1500 microns, not greater than about 1000 microns.
Item 4. The abrasive article of item 1, further comprising a second type of abrasive particle different than the first type of abrasive particle, wherein the first type of abrasive particle is more friable than the second type of abrasive particle.
Item 5. The abrasive article of item 4, wherein the second type of abrasive particle comprises an average particle size of at least about 200 microns, at least about 400 microns, at least about 600 microns, at least about 800 microns, at least about 1000 microns, at least about 1500 microns, at least about 2000 microns, at least about 2500 microns, at least about 3000 microns, at least about 4000 microns, not greater than about 3000 microns, not greater than about 2500 microns, not greater than about 2000 microns, not greater than about 1500 microns, not greater than about 1000 microns.
Item 6. The abrasive article of item 4, wherein the second type of abrasive particle comprises alumina, wherein the second type of abrasive particle comprises zirconia, wherein the second type of abrasive particle comprises zirconia and alumina, wherein the second type of abrasive particle consists essentially of zirconia and alumina, wherein the second type of abrasive particle comprises a greater content of alumina as compared to a content of zirconia, wherein the second type of abrasive particle comprises a majority content of alumina and a minority content of zirconia, wherein the second type of abrasive particle comprises at least about 60% alumina, at least about 70% alumina, at least about 75% alumina, and not greater than about 98% alumina, not greater than about 95% alumina, not greater than about 90% alumina, not greater than about 85% alumina, at least about 5% zirconia, at least about 10% zirconia, at least about 15% zirconia, and not greater than about 40% zirconia, not greater than about 35% zirconia, not greater than about 30% zirconia, not greater than about 25% zirconia.
Item 7. The abrasive article of item 1, wherein the body comprise a blend of the first type of abrasive particles and a second type of abrasive particles different than the first type of abrasive particles, wherein the blend comprises a different amount (vol %) of the first type of abrasive particle than an amount (vol %) of the second type of abrasive particles, wherein the blend comprises a greater amount of the first type of abrasive particles than the amount of the second type of abrasive particles, wherein the blend comprises a ratio (AP1/AP2) of at least about 0.01 and not greater than about 4, wherein AP1 represents the weight of first type of abrasive particles in the blend and AP2 represents the weight of the second type of abrasive particles in the blend, at least about 0.05, at least about 0.08, at least about 0.1, at least about 0.12, at least about 0.14, at least about 0.16, and not greater than about 3, not greater than about 2, not greater than about 1.5, not greater than about 1, not greater than about 0.9, not greater than about 0.7, not greater than about 0.6, not greater than about 0.5, not greater than about 0.4.
Item 8. The abrasive article of item 1, wherein the body comprises a total content of abrasive particles of not greater than about 75 vol % for the total volume of the body, not greater than about 70 vol %, not greater than about 65 vol % not greater than about 60 vol %, not greater than about 55 vol %, not greater than about 50 vol % not greater than about 45 vol %, not greater than about 40 vol %, not greater than about 35 vol %, and at least about 30 vol %, at least about 35 vol %, at least about 40 vol %, at least about 45 vol %, at least about 50 vol %, at least about 55 vol %, at least about 60 vol %, at least about 65 vol %.
Item 9. The abrasive article of item 1, wherein the body comprises a total content of bond material of not greater than about 70 vol % for the total volume of the body, not greater than about 65 vol %, not greater than about 60 vol % not greater than about 55 vol %, not greater than about 50 vol %, not greater than about 45 vol % not greater than about 40 vol %, not greater than about 35 vol %, not greater than about 30 vol %, and at least about 25 vol %, at least about 30 vol %, at least about 35 vol %, at least about 40 vol %, at least about 45 vol %, at least about 50 vol %, at least about 55 vol %, at least about 60 vol %, at least about 65 vol %.
Item 10. The abrasive article of item 1, wherein the body comprises porosity, wherein the body comprises a total content of porosity of not greater than about 10 vol % porosity for a total volume of the body, not greater than about 9 vol %, not greater than about 8 vol %, not greater than about 7 vol %, not greater than about 6 vol %, not greater than about 5 vol %, not greater than about 4 vol %, not greater than about 3 vol %, not greater than about 2 vol %, at least about 0.05 vol % porosity, at least about 0.5 vol %, at least about 1 vol %, at least about 2 vol %, at least about 3 vol %, at least about 4 vol %, at least about 5 vol %, at least about 6 vol %, at least about 7 vol %, at least about 8 vol %.
Item 11. The abrasive article of item 1, wherein the bond material comprises a material selected from the group consisting of an inorganic material, an organic material, and a combination thereof, wherein the bond material comprises an organic material selected from the group consisting of epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins, and a combination thereof, wherein the bond consists essentially of a resin.
Item 12. The abrasive article of item 1, wherein the body further comprises a filler, wherein the bond material further comprises a filler material, wherein the filler comprises a material selected from the group consisting of powders, granules, spheres, fibers, and a combination thereof, wherein the filler comprises a material selected from the group consisting of an inorganic material, an organic material, and a combination thereof, wherein the filler comprises a material selected from the group consisting of sand, bubble alumina, bauxite, chromites, magnesite, dolomites, bubble mullite, borides, titanium dioxide, carbon products (e.g., carbon black, coke or graphite), wood flour, clay, talc, hexagonal boron nitride, molybdenum disulfide, feldspar, nepheline syenite, glass spheres, glass fibers, CaF₂, KBF₄, Cryolite (Na₃AlF₆), potassium Cryolite (K₃AlF₆), pyrites, ZnS, copper sulfide, mineral oil, fluorides, carbonates, calcium carbonate, and a combination thereof, wherein the filler comprises a material selected from the group consisting of an antistatic agent, a metal oxide, a lubricant, a porosity inducer, coloring agent, and a combination thereof.
Item 13. The abrasive article of item 1, wherein the body is configured to conduct a material removal operation on a workpiece comprising titanium, wherein the material removal operation is selected from the group consisting of cutting, grinding, finishing, and a combination thereof.
Item 14. The abrasive article of item 1, wherein the body comprises a burnout modulus of rupture (MOR) of at least about 1.6 MPa, at least about 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, at least about 2.2 MPa, and not greater than about 10 MPa, not greater than about 8 MPa.
Item 15. The abrasive article of item 1, wherein the body comprises a burnout elastic modulus (EMOD) of at least about 250 MPa, at least about 270 MPa, at least about 300 MPa, at least about 325 MPa, at least about 350 MPa, at least about 375 MPa, at least about 400 MPa, at least about 425 MPa, at least about 450 MPa, and not greater than about 1000 MPa, not greater than about 800 MPa.
Item 16. The abrasive article of item 1, wherein the body comprises a relative material removal rate (MRR) improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article, at least about 8%, at least about 10%, at least about 12%, at least about 15%, and not greater than about 80%, not greater than about 50%, not greater than about 40%.
Item 17. The abrasive article of item 1, wherein the body comprises a relative life improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article, at least about 8%, at least about 10%, at least about 12%, at least about 15%, and not greater than about 80%, not greater than about 50%, not greater than about 40%.
Item 18. The abrasive article of item 4, wherein the first type of abrasive particle is at least about 50% more friable than the second type of abrasive particle, about 60% more friable, about 70% more friable, about 80% more friable, and not greater than 150% more friable than the second type of abrasive particle, not greater than 125%, not greater than 100%.
Item 19. The abrasive article of item 1, wherein, to break 50% of the first type of abrasive particles, at least about 220 N is required, at least about 230 N, at least about 240 N, at least about 250 N, or no greater than about 1500 N, no greater than about 1000 N, no greater than about 500 N.
Item 20. The abrasive article of item 4, wherein, to break 50% of the second type of abrasive particles, at least about 300 N, at least about 500 N, at least about 1000 N, or no greater than about 2400 N, no greater than about 2300 N, no greater than about 2200 N is required.
Item 21. The abrasive article of item 1, wherein, to break 90% of the first type of abrasive particles, at least about 300 N, at least about 325 N, at least about 350 N, or no greater than about 2000 N, no greater than about 1500 N, no greater than about 500 N is required.
Item 22. The abrasive article of item 4, wherein, to break 90% of the second type of abrasive particles, at least about 500 N, at least about 750 N, at least about 1000 N, at least about 1500 N, or no greater than about 3300 N, no greater than about 3200 N, no greater than about 3100 N, no greater than about 3000 N is required.
Item 23. The abrasive article of item 1, wherein the first type of abrasive particle has a hardness of at least about 15.7, at least about 16, at least about 16.5, no greater than about 19, no greater than about 18.5, no greater than about 18, no greater than about 17.5.
Item 24. The abrasive article of item 4, wherein the second type of abrasive has a hardness of at least about 14, at least about 14.25, at least about 14.5, or no greater than about 16.5, no greater than about 16.25, no greater than about 16, no greater than about 15.75.
Item 25. The abrasive article of item 4, wherein the first type of abrasive particle is about 1% harder than the second type of abrasive particle, about 3% harder, about 5% harder, about 10% harder than the second type of abrasive particle, not greater than 30% harder than the first type of abrasive particle, not greater than 25%, not greater than 20%, not greater than 18%, not greater than 16% harder than the second type of abrasive particle.
Item 26. An abrasive article configured to work titanium comprising: a body including: a bond material comprising an organic material; a first type of abrasive particles contained within the bond material comprising fused alumina; and wherein the body comprises a burnout modulus of rupture (MOR) of at least about 1.6 MPa.
Item 27. The abrasive article of item 26, wherein the first type abrasive particles consist essentially of fused alumina.
Item 28. The abrasive article of item 26, wherein the first type of abrasive particle comprises an average particle size of at least about 500 microns and not greater than about 3000 microns.
Item 29. The abrasive article of item 26, further comprising a second type of abrasive particle different than the first type of abrasive particle, wherein the second type of abrasive particle comprises a different average particle size as compared to an average particle size of the first type of abrasive particle.
Item 30. The abrasive article of item 29, wherein the second type of abrasive particle comprises an average particle size of at least about 500 microns and not greater than about 3000 microns.
Item 31. The abrasive article of item 29, wherein the second type of abrasive particle comprises zirconia and alumina.
Item 32. The abrasive article of item 26, wherein the body comprise a blend of the first type of abrasive particles and a second type of abrasive particles different than the first type of abrasive particles, wherein the blend comprises a different amount (vol %) of the first type of abrasive particle than an amount (vol %) of the second type of abrasive particles, wherein the blend comprises a greater amount of the first type of abrasive particles than the amount of the second type of abrasive particles, wherein the blend comprises a ratio (AP1/AP2) of at least about 0.01 and not greater than about 4.
Item 33. The abrasive article of item 26, wherein the body comprises a total content of abrasive particles of not greater than about 75 vol % for the total volume of the body, and at least about 30 vol %.
Item 34. The abrasive article of item 26, wherein the body comprises a total content of bond material of not greater than about 70 vol % for the total volume of the body, and at least about 25 vol %.
Item 35. The abrasive article of item 26, wherein the body comprises porosity, wherein the body comprises a total content of porosity of not greater than about 10 vol % for the total volume of the body, and at least about 1 vol %.
Item 36. The abrasive article of item 26, wherein the bond material comprises a material selected from the group consisting of an inorganic material, an organic material, and a combination thereof, wherein the bond material comprises an organic material selected from the group consisting of epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins, and a combination thereof, wherein the bond consists essentially of a resin.
Item 37. The abrasive article of item 26, wherein the body further comprises a filler.
Item 38. The abrasive article of item 26, wherein the body is configured to conduct a material removal operation on a workpiece comprising titanium, wherein the material removal operation is selected from the group consisting of cutting, grinding, finishing, and a combination thereof.
Item 39. The abrasive article of item 26, wherein the burnout modulus of rupture (MOR) of at least about 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, at least about 2.2 MPa, and not greater than about 10 MPa, not greater than about 8 MPa.
Item 40. The abrasive article of item 26, wherein the body comprises a burnout elastic modulus (EMOD) of at least about 250 MPa, at least about 270 MPa, at least about 300 MPa, at least about 325 MPa, at least about 350 MPa, at least about 375 MPa, at least about 400 MPa, at least about 425 MPa, at least about 450 MPa, and not greater than about 1000 MPa, not greater than about 800 MPa.
Item 41. The abrasive article of item 29, wherein the first type of abrasive particle is at least about 50% more friable than the second type of abrasive particle, about 60% more friable, about 70% more friable, about 80% more friable, and not greater than 150% more friable than the second type of abrasive particle, not greater than 125%, not greater than 100%.
Item 42. The abrasive article of item 26, wherein, to break 50% of the first type of abrasive particles, at least about 220 N is required, at least about 230 N, at least about 240 N, at least about 250 N, or no greater than about 1500 N, no greater than about 1000 N, no greater than about 500 N.
Item 43. The abrasive article of item 29, wherein, to break 50% of the second type of abrasive particles, at least about 300 N, at least about 500 N, at least about 1000 N, or no greater than about 2400 N, no greater than about 2300 N, no greater than about 2200 N is required.
Item 44. The abrasive article of item 26, wherein, to break 90% of the first type of abrasive particles, at least about 300 N, at least about 325 N, at least about 350 N, or no greater than about 2000 N, no greater than about 1500 N, no greater than about 500 N is required.
Item 45. The abrasive article of item 29, wherein, to break 90% of the second type of abrasive particles, at least about 500 N, at least about 750 N, at least about 1000 N, at least about 1500 N, or no greater than about 3300 N, no greater than about 3200 N, no greater than about 3100 N, no greater than about 3000 N is required.
Item 46. The abrasive article of item 26, wherein the first type of abrasive particle has a hardness of at least about 15.7, at least about 16, at least about 16.5, no greater than about 19, no greater than about 18.5, no greater than about 18, no greater than about 17.5.
Item 47. The abrasive article of item 29, wherein the second type of abrasive has a hardness of at least about 14, at least about 14.25, at least about 14.5, or no greater than about 16.5, no greater than about 16.25, no greater than about 16, no greater than about 15.75.
Item 48. The abrasive article of item 29, wherein the first type of abrasive particle is about 1% harder than the second type of abrasive particle, about 3% harder, about 5% harder, about 10% harder than the second type of abrasive particle, not greater than 30% harder than the first type of abrasive particle, not greater than 25%, not greater than 20%, not greater than 18%, not greater than 16% harder than the second type of abrasive particle.
Item 49. An abrasive article configured to work titanium comprising: a body including: a bond material comprising an organic material; a first type of abrasive particles contained within the bond material comprising fused alumina; and wherein the body comprises a burnout elastic modulus (EMOD) of at least about 250 MPa.
Item 50. The abrasive article of item 49, wherein the first type abrasive particles consist essentially of fused alumina.
Item 51. The abrasive article of item 49, wherein the first type of abrasive particle comprises an average particle size of at least about 500 microns and not greater than about 3000 microns.
Item 52. The abrasive article of item 49, further comprising a second type of abrasive particle different than the first type of abrasive particle, wherein the second type of abrasive particle comprises a different average particle size as compared to an average particle size of the first type of abrasive particle.
Item 53. The abrasive article of item 52, wherein the second type of abrasive particle comprises an average particle size of at least about 500 microns and not greater than about 3000 microns.
Item 54. The abrasive article of item 52, wherein the second type of abrasive particle comprises zirconia and alumina.
Item 55. The abrasive article of item 49, wherein the body comprise a blend of the first type of abrasive particles and a second type of abrasive particles different than the first type of abrasive particles, wherein the blend comprises a different amount (vol %) of the first type of abrasive particle than an amount (vol %) of the second type of abrasive particles, wherein the blend comprises a greater amount of the first type of abrasive particles than the amount of the second type of abrasive particles, wherein the blend comprises a ratio (AP1/AP2) of at least about 0.01 and not greater than about 4.
Item 56. The abrasive article of item 49, wherein the body comprises a total content of abrasive particles of not greater than about 75 vol % for the total volume of the body, and at least about 30 vol %.
Item 57. The abrasive article of item 49, wherein the body comprises a total content of bond material of not greater than about 70 vol % for the total volume of the body, and at least about 25 vol %.
Item 58. The abrasive article of item 49, wherein the body comprises porosity, wherein the body comprises a total content of porosity of not greater than about 10 vol % for the total volume of the body.
Item 59. The abrasive article of item 49, wherein the bond material comprises a material selected from the group consisting of an inorganic material, an organic material, and a combination thereof, wherein the bond material comprises an organic material selected from the group consisting of epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins, and a combination thereof, wherein the bond consists essentially of a resin.
Item 60. The abrasive article of item 49, wherein the body further comprises a filler.
Item 61. The abrasive article of item 49, wherein the body is configured to conduct a material removal operation on a workpiece comprising titanium, wherein the material removal operation is selected from the group consisting of cutting, grinding, finishing, and a combination thereof.
Item 62. The abrasive article of item 49, wherein the burnout modulus of rupture (MOR) of at least about 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, at least about 2.2 MPa, and not greater than about 10 MPa, not greater than about 8 MPa.
Item 63. The abrasive article of item 49, wherein the body comprises a burnout elastic modulus (EMOD) of at least about 270 MPa, at least about 300 MPa, at least about 325 MPa, at least about 350 MPa, at least about 375 MPa, at least about 400 MPa, at least about 425 MPa, at least about 450 MPa, and not greater than about 1000 MPa, not greater than about 800 MPa.
Item 64. An abrasive article comprising: a bonded abrasive body configured to work titanium comprising: a bond material; and a blend of abrasive particles contained within the bond material, the blend comprising: a first type of abrasive particles comprising fused alumina; and a second type of abrasive particles comprising zirconia.
Item 65. A method of working titanium comprising: providing a workpiece comprising titanium; and moving a bonded abrasive body relative to the workpiece to conduct a material removal process on the workpiece, wherein the bonded abrasive body comprises a relative material removal rate (MRR) improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article.
Item 66. The abrasive article of item 65, wherein the body comprises a relative material removal rate improvement of at least about 8%, at least about 10%, at least about 12%, at least about 15%, and not greater than about 80%, not greater than about 50%, not greater than about 40%.
Item 67. The abrasive article of item 65, wherein the body comprises a burnout modulus of rupture (MOR) of at least about 1.6 MPa, at least about 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, at least about 2.2 MPa, and not greater than about 10 MPa, not greater than about 8 MPa.
Item 68. The abrasive article of item 65, wherein the body comprises a burnout elastic modulus (EMOD) of at least about 250 MPa, at least about 270 MPa, at least about 300 MPa, at least about 325 MPa, at least about 350 MPa, at least about 375 MPa, at least about 400 MPa, at least about 425 MPa, at least about 450 MPa, and not greater than about 1000 MPa, not greater than about 800 MPa.
Item 69. The abrasive article of item 65, wherein the body comprises a relative life improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article, at least about 8%, at least about 10%, at least about 12%, at least about 15%, and not greater than about 80%, not greater than about 50%, not greater than about 40%.
Item 70. The abrasive article of item 65, wherein the body comprises a first type abrasive particles consist essentially of fused alumina.
Item 71. The abrasive article of item 70, wherein the first type of abrasive particle comprises an average particle size of at least about 500 microns and not greater than about 3000 microns.
Item 72. The abrasive article of item 70, further comprising a second type of abrasive particle different than the first type of abrasive particle, wherein the second type of abrasive particle comprises a different average particle size as compared to an average particle size of the first type of abrasive particle.
Item 73. The abrasive article of item 72, wherein the second type of abrasive particle comprises an average particle size of at least about 500 microns and not greater than about 3000 microns.
Item 74. The abrasive article of item 72, wherein the second type of abrasive particle comprises zirconia and alumina.
Item 75. The abrasive article of item 65, wherein the body comprise a blend of a first type of abrasive particles and a second type of abrasive particles different than the first type of abrasive particles, wherein the blend comprises a different amount (vol %) of the first type of abrasive particle than an amount (vol %) of the second type of abrasive particles, wherein the blend comprises a greater amount of the first type of abrasive particles than the amount of the second type of abrasive particles, wherein the blend comprises a ratio (AP1/AP2) of at least about 0.01 and not greater than about 4.
Item 76. The abrasive article of item 65, wherein the body comprises a total content of abrasive particles of not greater than about 75 vol % for the total volume of the body, and at least about 30 vol %.
Item 77. The abrasive article of item 65, wherein the body comprises a total content of bond material of not greater than about 70 vol % for the total volume of the body, and at least about 25 vol %.
Item 78. The abrasive article of item 65, wherein the bond material comprises a material selected from the group consisting of an inorganic material, an organic material, and a combination thereof, wherein the bond material comprises an organic material selected from the group consisting of epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins, and a combination thereof, wherein the bond consists essentially of a resin.
Item 79. The abrasive article of item 65, wherein the material removal operation is selected from the group consisting of cutting, grinding, finishing, and a combination thereof.
Item 80. The abrasive article of item 64, wherein the bond material comprises a resin having a high temperature flexure modulus of at least 1.05.
Item 81. The abrasive article of item 64, wherein at least one of types of the abrasive particles has a cross-sectional shape as viewed in two dimensions comprising an ellipse, circle, triangle, rectangle, pentagon, hexagon, heptagon or octagon.

EXAMPLES

Example 1

The body of the abrasive articles of the embodiments herein may have particular performance properties, including for example, a material removal rate (MRR). For example, according to one aspect, the body comprises a relative material removal rate (MRR) improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article. The material removal rate test was conducted according to the following conditions. Material removal (in pounds) is calculated by the difference between the start and final weights of the grinded material (e.g., titanium slabs). During grinding, the contact time is monitored while the grinding wheel and material is in contact. Then, material removal rate (MRR, lbs/hr) can be calculated as material removal (lbs) divided by contact time (hr). As shown in Table 1, the conventional abrasive article and the inventive wheel comprised the following:

	TABLE 1

	Conventional Wheel		Exemplary Wheel

	MATERIAL	VOL %	MATERIAL	VOL %

ZF-grit 6	27	ZF-grit 6	22
ZF-grit 8	9	57A-grit 6	9
ZF-grit 10	9	ZF-grit 8	7
30 grit fine	13	57A-grit 8	3
29-722 resin	24	ZF-grit 10	7
saran	1	57A-grit 10	3
CAM	9	30 grit fine	11
	0	Exemplary resin	22
0	0	Saran	1
LIME	4	CAM	7
0	0	0	0
0	0	LIME	3
0	0	0	0
	0	0	0
chop strand fiber	4	0	0
	0	chop strand fiber	4

The test conditions appear in Table 2.

	TABLE 2

	Condition	Setting

	Wheel Size	25 × 4 × 12″
	Stub Size	Fine Center size ~15.5″
	Material Shape	Rectangular and octagon Titanium billets
	Wheel Speed	1955
	Crossfeed	0.75 in
	Traverse speed	272 fpm
	Grinding pressure	1100 psi
	Grind angle
	90°

The test results are displayed in Table 3.

TABLE 3

						Relative
						MRR
			Con-	Material		com-
		Material	tact	Removal		pared
	Wheel	Removal	time	Rate	Average	to
Specification	number	(lbs)	(hr)	(MRR)	MRR	STD

STD		526	1.18	445.76	445.76	—
NEW SPEC	1	556	1.06	524.53	528.50	18.56%
	2	622	1.08	575.93
	3	616	1.27	485.04

In some instances, the relative material removal rate improvement can be at least about 8%, at least about 10%, at least about 12%, or even at least about 15%. Still, in at least one embodiment, the relative material removal rate improvement may be not greater than about 80%, such as not greater than about 50%. It will be appreciated that the relative material removal rate improvement of the body can be within a range between any of the minimum and maximum percentages noted above.
In addition to the relative improvement in material removal rate, the same test procedure demonstrates an improvement in life of the article over conventional abrasive articles. Life improvement may be characterized by Q ratio, which is the amount of metal removal divided by the amount of wheel wear. For example, according to one embodiment, the body can have a relative life improvement of at least about 5% for a standard titanium grinding test as compared to a conventional abrasive article under the conditions noted above for relative material removal rate improvement. In another embodiment, the relative life improvement can be at least about 8%, such as at least about 10%, at least about 12%, or even at least about 15%. Still, in at least one non-limiting embodiment, the relative life improvement can be not greater than about 80%, such as not greater than about 50%. It will be appreciated that the relative life improvement of the body can be within a range between any of the minimum and maximum percentages noted above.

Example 2

Two general abrasive articles are made including a general conventional sample (CS1) and an inventive first sample (S1) representative of an embodiment herein. Samples CS1 and S1 are grinding wheels constructed as described above in Table 1.
Various specific samples if CS1 were made, wherein the content of alumina-zirconia grains is substituted for a particular content of fused alumina grains commercially available as 57A from Washington Mills. Notably, three distinct specific examples of the general conventional samples CS1 is made, wherein the first specific sample (CS1a) having 0 vol % of 57A abrasive grains, a second specific sample (CS1b) having 15.5 vol % of 57A abrasive grains, and a third specific sample (CS1c) having approximately 52 vol % of 57A abrasive grains.
Various specific samples if S1 are made, wherein the content of alumina-zirconia grains is substituted for a particular content of fused alumina grains commercially available as 57A from Washington Mills. Notably, two distinct specific examples of sample S1 are made, wherein the first specific sample (S1a) has 0 vol % of 57A abrasive grains, and a second specific sample (Sib) has 15.5 vol % of 57A abrasive grains
FIG. 1 includes a plot of relative performance versus content of a particular type of abrasive particle for the three specific conventional samples and specific samples representative of embodiments herein. The test conditions were the same as those described above in Table 2. As illustrated, for the specific conventional samples (CS1a, CS1b, and CS1c) with increasing content of fused alumina grains, the relative performance of the abrasive article decreases. By contrast, the relative performance of samples S1a and S1b is dramatically improved over all of the specific conventional samples. Sample S1b demonstrates a relative performance improvement of over 40% compared to sample CS1b.
FIG. 2 is a plot of relative material removal rate versus content of a particular type of abrasive particle for a conventional sample and a sample representative of an embodiment herein. The test conditions were the same as those described above in Table 2. As illustrated, for the specific conventional samples (CS1a, CS1b, and CS1c) with increasing content of fused alumina grains, the relative material removal rate of the abrasive article decreases. By contrast, the relative material removal rate of samples S1a and S1b is dramatically improved over all of the specific conventional samples. In fact, Sample S1b demonstrates a relative material removal rate improvement of approximately 40% compared to sample CS1b.

Example 3

FIG. 3 is a Weibull probability plot for a particle crush strength test of two samples, S11 and S12. For this test, the test frame was MTS Sintech 2/G, the test method was single particle crush, the fixture had carbide platens with a load cell of 1000 lbs, and the test speed was 2 μm/sec. The single particle crush test was conducted on a Sintech 2/G machine, commercially available from MTS Corporation. A 6 grit-size particle was prepared and placed between two platens of polycrystalline diamond. A 1000 lb load cell was selected for a compression method test using Testworks software on the Sintech 2/G machine. The compression test was initiated by selecting a test speed of 2 microns/second and a pre-load of less than 2 N. The test is completed when the particle is sufficiently fractured under the load cell and the force necessary to fracture is determined by the Sintech 2/G machine. At least 30 particles were tested and a Weibull plot was generated, such as the plot illustrated in FIG. 3, herein.
The sample S12 is alumina 57A. The sample S11 is zirconia grain ZF. The horizontal x-axis depicts the force (in newtons) required to break the grains. The vertical y-axis depicts the percentage of the grains broken when subjected to breaking force. A 95% confidence interval (CI) is indicated by the lines surrounding each of the two sets of plotted data. To compare the grain crush strength of each sample, representative measurements may be made at both 50% of the grains broken, and at 90% of the grains broken. For example, at the 50% interval, the lower 95% confidence interval for S12 is about 220 N, and the upper 95% confidence interval for S12 is about 280 N. Also at the 50% interval, the lower 95% confidence interval for S11 is about 1800 N. Thus, at a minimum, S12 has a lower grain crush strength than S11 by about (1800−280)/1800=1520/1800=84%. At the other extreme of the 50% interval, the upper 95% confidence interval for S11 is about 2100 N, and the lower 95% confidence interval for S12 is about 220 N. Also at the 95% interval, the upper 95% confidence interval for S11 is about 2100 N. Thus, at a maximum, S12 has a lower grain crush strength than S11 by about (2100−220)/2100=1880/2100=90%.
At the 90% interval, the lower 95% confidence interval for S11 is about 2300 N, and the upper 95% confidence interval for S12 is about 400 N. Thus, at a minimum, S12 has a lower grain crush strength than S11 by about (2300−400)/2300=1900/2300=83%. At the other extreme of the 90% interval, the upper 95% confidence interval for S11 is about 2900 N, and the lower 95% confidence interval for S12 is about 300 N. Thus, at a maximum, S12 has a lower grain crush strength than S11 by about (2900−300)/2900=2600/2900=90%. Thus, sample S12 is more friable than sample S11.

Example 4

Table 4 comprises data for grain toughness and hardness tests of the same two samples in Example 2, S11 and S12. The toughness test method was K1C by indentation fracture. Each grain was encapsulated in epoxy, polished to provide a flat surface, and then the flat surface was indented. The input parameters were a load of 0.5 kg and elastic modulus of 410 GPa.

	TABLE 4

	Toughness	Hardness
	K1C in MPa m^1/2	Hv in GPa

S12	2.06 +/− 0.20	16.99 +/− 0.47
S11	3.39 +/− 0.16	15.22 +/− 0.43

In terms of toughness, sample S12 has a K1C of 2.06+/−0.20 MPa m^1/2(or max 2.26 and min 1.86). Sample S11 has a K1C of 3.39+/−0.16 MPa m^1/2(or max 3.55 and min 3.23). Thus, at a minimum, S12 has a lower grain toughness than sample S11 by about (3.23−2.26)/3.23=0.97/3.23=30%. At a maximum, S12 has a lower grain toughness than S11 by about (3.55−1.86)/3.55=1.69/3.55=48%.
In terms of hardness, sample S12 has a Hv of 16.99+/−0.47 GPa (or max 17.46 and min 16.52). Sample S11 has a Hv of 15.22+/−0.43 GPa (or max 15.65 and min 14.79). Thus, at a minimum, S11 has a lower hardness than S12 by about (16.52−15.65)/16.52=0.87/16.52=5%. At a maximum, S11 has a lower hardness than S12 by about (17.46−14.79)/17.46=2.67/17.46=15%.
The processes and abrasive articles disclosed herein represent a departure from the state-of-the-art. Abrasive articles herein can utilize a combination of features, including but limited to, certain types of abrasive particles, particular blends of abrasive particle types, porosity, bond material, content of bond material, content of abrasive particles, content of abrasive particle types, relative performance improvement, relative material removal rate improvement, and a combination thereof. While not entirely understood, the combination of features facilitates the formation of abrasive articles that have demonstrated unexpected and remarkably improved performance over state of the art abrasive articles.
The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
The Abstract of the Disclosure is provided to comply with Patent Law and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description of the Drawings, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description of the Drawings, with each claim standing on its own as defining separately claimed subject matter.

Claims

What is claimed is:

1. An abrasive article configured to work titanium comprising:

a body including:

a bond material comprising a resin having a high temperature flexure modulus of at least 1.05; and

a first type of abrasive particles contained within the bond material comprising fused alumina.

2. The abrasive article of claim 1, wherein the first type abrasive particles consist essentially of fused alumina.

3. The abrasive article of claim 1, wherein the first type of abrasive particle comprises an average particle size of at least about 200 microns.

4. The abrasive article of claim 1, further comprising a second type of abrasive particle different than the first type of abrasive particle.

5. The abrasive article of claim 4, wherein the second type of abrasive particle comprises an average particle size of at least about 200 microns.

6. The abrasive article of claim 4, wherein the second type of abrasive particle comprises at least about 60% and not greater than about 95% alumina, and at least about 5% and not greater than about 40% zirconia.

7. The abrasive article of claim 1, wherein the body comprise a blend of the first type of abrasive particles and a second type of abrasive particles different than the first type of abrasive particles, wherein the blend comprises a different amount (vol %) of the first type of abrasive particle than an amount (vol %) of the second type of abrasive particle.

8. The abrasive article of claim 7, wherein the blend comprises a ratio (AP1/AP2) of at least about 0.01 and not greater than about 4, wherein AP1 represents the weight of first type of abrasive particles in the blend and AP2 represents the weight of the second type of abrasive particles in the blend.

9. The abrasive article of claim 1, wherein the body comprises a total content of abrasive particles of not greater than about 75 vol % and at least about 30 vol % for a total volume of the body.

10. The abrasive article of claim 1, wherein the body comprises a total content of bond material of not greater than about 70 vol % and at least about 25 vol % for the total volume of the body.

11. The abrasive article of claim 1, wherein the body comprises a total content of porosity of not greater than about 10 vol % and at least about 0.05 vol % porosity for a total volume of the body.

12. The abrasive article of claim 1, wherein the bond material comprises an organic material selected from the group consisting of epoxy resins, polyester resins, polyurethanes, polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide, modified phenolic resins, and a combination thereof.

13. The abrasive article of claim 1, wherein the body further comprises a filler comprising a material selected from the group consisting of powders, granules, spheres, fibers, sand, bubble alumina, bauxite, chromites, magnesite, dolomites, bubble mullite, borides, titanium dioxide, carbon products (e.g., carbon black, coke or graphite), wood flour, clay, talc, hexagonal boron nitride, molybdenum disulfide, feldspar, nepheline syenite, glass spheres, glass fibers, CaF₂, KBF₄, Cryolite (Na₃AlF₆), potassium Cryolite (K₃AlF₆), pyrites, ZnS, copper sulfide, mineral oil, fluorides, carbonates, calcium carbonate, and a combination thereof.

14. The abrasive article of claim 1, wherein the body is configured to conduct a material removal operation on a workpiece comprising titanium.

15. The abrasive article of claim 1, wherein the body comprises a burnout modulus of rupture (MOR) of at least about 1.6 MPa and not greater than about 10 MPa.

16. The abrasive article of claim 1, wherein the body comprises a burnout elastic modulus (EMOD) of at least about 250 MPa and not greater than about 1000 MPa.

17. The abrasive article of claim 1, wherein the body comprises a relative material removal rate (MRR) improvement of at least about 5% and not greater than about 80% for a standard titanium grinding test as compared to a conventional abrasive article.

18. The abrasive article of claim 1, further comprising a second type of abrasive particle different than the first type of abrasive particle, wherein the first type of abrasive particle is at least about 50% more friable than the second type of abrasive particle.

19. The abrasive article of claim 1, wherein to break 90% of the first type of abrasive particles, at least about 300 N and no greater than about 1500 N is required.

20. The abrasive article of claim 1, further comprising a second type of abrasive particle different than the first type of abrasive particle, wherein to break 90% of the second type of abrasive particles, at least about 500 N and greater than about 3300 N is required.