CN104640675B

CN104640675B - Abrasive article for lower speed grinding operations

Info

Publication number: CN104640675B
Application number: CN201380042495.8A
Authority: CN
Inventors: N·萨兰基; S·J·如克马尼; S·E·福克斯; R·L·克劳斯
Original assignee: Saint Gobain Abrasifs SA; Saint Gobain Abrasives Inc
Current assignee: Saint Gobain Abrasifs SA; Saint Gobain Abrasives Inc
Priority date: 2012-07-06
Filing date: 2013-07-03
Publication date: 2017-05-24
Anticipated expiration: 2033-07-03
Also published as: RU2603515C2; AR091657A1; IN2015DN00417A; US20140007517A1; JP5921772B2; IL236438B; CN104640675A; MX2015000143A; BR112015000164A2; ZA201500148B; KR20150036225A; KR101704416B1; EP2869968A1; JP2015521963A; EP3900878A2; WO2014008356A1; BR112015000164B1; EP2869968A4; EP2869968B1; EP3900878A3

Abstract

An abrasive article includes a bonded abrasive body having abrasive particles contained within a bond material. The bonded abrasive body may include an abrasive particle-to-bond material interfacial modulus of elasticity (MOE) of at least about 225 GPa. The bonded abrasive body may be configured to grind a workpiece comprising metal at a speed of less than about 60 m/s.

Description

Abrasive article for low speed grinding operations

Technical Field

The following relates to abrasive articles and, in particular, to bonded abrasive articles suitable for performing low speed grinding operations.

Background

Abrasive tools are typically formed with abrasive grains contained in a bond material for material removal applications. Superabrasive grains (e.g., diamond or cubic boron nitride) or seeded (or even non-seeded) sintered sol gel alumina abrasive grains, also known as microcrystalline a alumina (MCA) abrasive grains, may be applied to such abrasive tools. The binder material may be an organic material, such as a resin, or an inorganic material, such as a glass or vitreous material. In particular, the use of vitreous bond materials and bonded abrasive tools comprising MCA grains or superabrasive grains is commercially advantageous for grinding.

Certain bonded abrasive tools, particularly those utilizing vitreous bond materials, require high temperature forming processes, typically about 1100 ℃ or higher, which can have a degrading effect on the abrasive grains of MCA. In fact, it has been recognized that at such elevated temperatures necessary to form an abrasive tool, the bond material can react with the abrasive grains, particularly MCA grains, and compromise the integrity of the abrasive, reducing the sharpness and performance characteristics of the grains. Accordingly, industry has turned to lowering the forming temperature necessary to form the bond material to inhibit high temperature degradation of the abrasive grains during the forming process. There is a continuing need in the industry to improve the performance of such bonded abrasive articles.

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 graphical representation of the percent porosity, percent abrasive, and percent bond material for a prior art bonded abrasive body and a bonded abrasive body according to embodiments herein.

Fig. 2 includes photographs illustrating modulus and hardness tests of abrasive grains, bond material, and their interfaces.

Fig. 3 includes a table of the elastic Modulus (MOE) of the abrasive particles, bond material, and abrasive particle-bond material interface of two conventional bonded abrasive articles compared to bonded abrasive articles according to embodiments herein.

Fig. 4 includes a table of the hardness of abrasive particles, bond material, and abrasive particle-bond material interfaces of two conventional bonded abrasive articles compared to bonded abrasive articles according to embodiments herein.

Fig. 5 includes a schematic of an abrasive article illustrating a loss of shape along both the x-axis and the y-axis.

Fig. 6 includes a plot of surface finish Ra versus feed rate (Z' w) for a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

Fig. 7 includes a plot of material removal versus feed rate (Z' w) at 5 passes for a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

Fig. 8 includes a graph illustrating the change in x-axis radius of an angle fixing factor (corner holding factor) versus feed rate (Z' w) for a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

Fig. 9 includes a graph illustrating the change in y-axis radius of the angular fixing factor versus feed rate (Z' w) for a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

Fig. 10 includes a chart of components per dressing for a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

Fig. 11 includes a graph of cycle times for a conventional bonded abrasive article and a bonded abrasive article according to an embodiment.

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

Detailed Description

The following relates to bonded abrasive articles that may be useful for grinding and shaping workpieces. It should be noted that the bonded abrasive articles of embodiments herein may include abrasive particles within a vitreous bond material. Suitable applications for using the bonded abrasive articles of embodiments herein include grinding operations including, for example, centerless grinding, cylindrical grinding, crankshaft grinding, various surface grinding operations, bearing and gear grinding operations, creep feed grinding, and various tool shop applications.

According to one embodiment, a method of forming a bonded abrasive article of an embodiment may begin by forming a mixture of suitable compounds and components to form a bond material. The binder material may be formed of a compound of an inorganic material, such as an oxide compound. For example, one suitable oxide material may include dioxygenSilicon (SiO)₂). According to one embodiment, the bond material may be formed from no more than about 55 wt% silica, based on the total weight of the bond material. In other embodiments, the amount of silica may be less, such as not more than about 54 wt%, not more than about 53 wt%, not more than about 52 wt%, or even not more than about 51 wt%. Further, in certain embodiments, the bond material may be formed from at least about 45 wt%, such as at least about 46 wt%, approximately at least about 47 wt%, at least about 48 wt%, or even at least about 49 wt% silica, based on the total weight of the bond material. It is to be understood that the amount of silica can be within a range between any of the minimum and maximum percentages noted above.

The bond material may also include a content of alumina (Al)₂O₃). For example, the bond material can include at least about 12 wt% alumina based on the total weight of the bond material. In other embodiments, the amount of alumina may be at least about 14 wt%, at least about 15 wt%, or even at least about 16 wt%. In certain instances, the bond material can include an amount of alumina of not greater than about 23 wt%, not greater than about 21 wt%, not greater than about 20 wt%, not greater than about 19 wt%, or even not greater than about 18 wt%, based on the total weight of the bond material. It is to be understood that the amount of alumina can be within a range between any of the minimum and maximum percentages noted above.

In some cases, the bond material may be formed from a particular ratio (SiO) of the amount of silica (measured as a weight percent) to the amount of alumina (measured as a weight percent)₂/Al₂O₃) And (4) forming. For example, the silica to alumina ratio may be described by the weight percent of silica divided by the weight percent of alumina in the bond material. According to one embodiment, the silica to alumina ratio may be not greater than about 3.2. In other cases, the ratio of silica to alumina in the bond material can be no greater than about 3.1, no greater than about 3.0, or even no greater than about 2.9. Further, in some cases, the bond material may be formed such that the ratio of the weight percent of silica to the weight percent of alumina may beAt least about 2.2, such as at least about 2.3, such as about at least about 2.4, at least about 2.5, at least about 2.6, or even at least about 2.7. It will be appreciated that the total amount of alumina and silica can be within a range between any of the minimum and maximum values noted above.

According to one embodiment, the bond material may be formed from an amount of boron oxide (B)₂O₃) And (4) forming. For example, the bond material may include not greater than about 20 wt% boron oxide for the total weight of the bond material. In other cases, the amount of boron oxide can also be less, such as not greater than about 19 wt%, not greater than about 18 wt%, not greater than about 17 wt%, or even not greater than about 16 wt%. Further, the bond material may be formed from at least about 11 wt%, such as at least about 12 wt%, at least about 13 wt%, or even at least about 14 wt% boron oxide, based on the total weight of the bond material. It is to be understood that the amount of boron oxide can be within a range between any of the minimum and maximum percentages noted above.

According to one embodiment, the bond material may be formed such that the total content (i.e., the sum) of the weight percent of boron oxide and the weight percent of silica in the bond material may be no greater than about 70 wt%, based on the total weight of the bond material. In other instances, the total content of silica and boron oxide can be no greater than about 69 wt%, such as no greater than about 68 wt%, no greater than about 67 wt%, or even no greater than about 66 wt%. According to a particular embodiment, the total weight percent content of silica and boron oxide may be at least about 55 wt%, such as at least about 58 wt%, at least about 60 wt%, at least about 62 wt%, at least about 63 wt%, at least about 64 wt%, or even at least about 65 wt%, based on the total weight of the bond material. It is to be understood that the total weight percent of silica and boron oxide in the bond material can be within a range between any of the minimum and maximum percentages noted above.

Additionally, in certain instances, the amount of silica in the bond material may be greater than the amount of boron oxide, measured as a weight percentage. It should be noted that the amount of silica may be at least about 1.5 times, at least about 1.7 times, at least about 1.8 times, at least about 1.9 times, at least about 2.0 times, or even at least about 2.5 times the amount of boron oxide. Further, in one embodiment, the bond material may include an amount of silica that is no greater than about 5 times, such as no greater than about 4 times, no greater than about 3.8 times, or even no greater than about 3.5 times. It will be appreciated that the difference in the amount of silica relative to the amount of boron oxide can be within a range between any of the minimum and maximum values noted above.

According to one embodiment, the binding material may be composed of at least one alkali metal oxide compound (R)₂O) wherein R represents a metal selected from the group IA elements of the periodic table. For example, the binding material may be selected from lithium oxide (Li)₂O), sodium oxide (Na)₂O), potassium oxide (K)₂O) and cesium oxide (Cs)₂O) and alkali metal oxide compounds (R) of combinations thereof₂O) is formed.

According to one embodiment, the bond material may be formed from alkali metal oxide compounds in a total content of no greater than about 20 wt%, based on the total weight of the bond material. For other bonded abrasive articles according to embodiments herein, the total content of alkali metal oxide compounds can be not greater than about 19 wt%, not greater than about 18 wt%, not greater than about 17 wt%, not greater than about 16 wt%, or even not greater than about 15 wt%. Further, in one embodiment, the total content of alkali metal oxide compounds in the bond material can be at least about 10 wt%, such as at least about 12 wt%, at least about 13 wt%, or even at least about 14 wt%. It is to be understood that the total content of alkali metal oxide compounds within the range between any of the minimum and maximum percentages noted above may be included in the bond material.

According to a particular embodiment, the bond material may be formed from no greater than about 3 of the above-described individual alkali metal oxide compounds (R2O). Indeed, certain bond materials may include no greater than about 2 alkali metal oxide compounds in the bond material.

In addition, the binder material may be formed such that the individual content of any alkali metal oxide compounds in the binder material does not exceed one-half of the total content (in weight percent) of alkali metal oxide compounds. In addition, according to a particular embodiment, the amount of sodium oxide may be greater than the content (weight percent) of lithium oxide or potassium oxide. In more particular instances, the total content of sodium oxide measured in weight percent may be greater than the sum of the content of lithium oxide and potassium oxide measured in weight percent. Additionally, in one embodiment, the amount of lithium oxide may be greater than the amount of potassium oxide.

According to one embodiment, the total amount of alkali metal oxide compounds, measured in weight percent, that form the bond material may be less than the amount of boron oxide (in weight percent) in the bond material. Indeed, in some instances, the total weight percent of alkali metal oxide compounds compared to the total weight percent of boron oxide in the bond material may be in the range of about 0.9 to 1.5, such as in the range of about 0.9 to 1.3, or even in the range of about 0.9 to 1.1.

The bond material may be formed from an amount of an alkaline earth metal compound (RO), where R represents a group IIA element of the periodic table of elements. For example, the bond material may include an alkaline earth oxide compound, such as calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), or even strontium oxide (SrO). According to one embodiment, the bond material may contain not greater than about 3.0 wt% alkaline earth oxide compound based on the total weight of the bond material. In other cases, the bond material can contain less alkaline earth oxide compounds, such as on the order of no greater than about 2.8 wt.%, no greater than about 2.2 wt.%, no greater than about 2.0 wt.%, or even no greater than about 1.8 wt.%. Further, according to one embodiment, the bond material may comprise one or more alkaline earth oxide compounds in an amount of at least about 0.5 wt%, such as at least about 0.8 wt%, at least about 1.0 wt%, or even at least about 1.4 wt%, based on the total weight of the bond material. It is to be understood that the amount of alkaline earth oxide compound in the bond material can be within a range between any of the minimum and maximum percentages noted above.

According to one embodiment, the bond material may be formed from no greater than about 3 different alkaline earth oxide compounds. In practice, the bond material may contain no more than 2 alkaline earth oxide compounds. In one particular case, the bond material may be formed from 2 alkaline earth oxide compounds consisting of calcium oxide and magnesium oxide.

In one embodiment, the bond material may include an amount of calcium oxide that is greater than an amount of magnesium oxide. Additionally, the amount of calcium oxide in the bond material may be greater than the content of any of the other alkaline earth oxide compounds present in the bond material.

The bond material can be formed from a combination of alkali metal oxide compounds and alkaline earth metal oxide compounds such that the total content is no greater than about 20 wt% based on the total weight of the bond material. In other embodiments, the total content of alkali metal oxide compounds and alkaline earth metal oxide compounds in the bond material can be no greater than about 19 wt%, such as no greater than about 18 wt%, or even no greater than about 17 wt%. However, in certain embodiments, the total content of alkali metal oxide compounds and alkaline earth metal oxide compounds present in the bond material may be at least about 12 wt%, such as at least about 13 wt%, such as at least about 14 wt%, at least about 15 wt%, or even at least about 16 wt%. It is to be understood that the bond material can have a total content of alkali metal oxide compounds and alkaline earth metal oxide compounds within a range between any of the minimum and maximum percentages noted above.

According to one embodiment, the bond material may be formed such that the content of alkali metal oxide compounds present in the bond material is greater than the total content of alkaline earth metal oxide compounds. In a particular embodiment, the bond material can be formed such that the ratio (R) of the total content (in weight percent) of the alkali metal oxide compounds to the total weight percent of the alkaline earth metal oxide compounds₂RO) is in the range of about 5: 1 to about 15: 1. In other embodiments, the total weight percent of alkali metal oxide compounds and alkaline earth metal oxide compounds present in the bond materialThe ratio of the total weight percent of (A) is in the range of about 6: 1 to about 14: 1, such as in the range of about 7: 1 to about 12: 1, or even in the range of about 8: 1 to about 10: 1.

According to one embodiment, the bond material may be formed from not greater than about 3wt phosphorous pentoxide, based on a total weight of the bond material. In certain other instances, the bond material can include not greater than about 2.5 wt%, such as not greater than about 2.0 wt%, not greater than about 1.5 wt%, not greater than about 1.0 wt%, not greater than about 0.8 wt%, not greater than about 0.5 wt%, or even not greater than about 0.2 wt% phosphorous pentoxide, based on the total weight of the bond material. Indeed, in some cases, the bond material may be substantially free of phosphorus pentoxide. Suitable levels of phosphorus pentoxide can contribute to certain characteristics and grinding performance characteristics as described herein.

According to one embodiment, the bond material may be formed from no more than about 1 wt% of certain oxide compounds (including, for example, such as MnO)₂、ZrSiO₂、CoAl₂O₄And an oxide compound of MgO). Indeed, in particular embodiments, the bond material may be substantially free of the oxide compounds noted above.

In addition to the bond material disposed in the mixture, the method of forming a bonded abrasive article can further include introducing a type of abrasive particle. According to one embodiment, the abrasive particles may comprise microcrystalline alumina (MCA). Indeed, in some instances, the abrasive particles may consist essentially of microcrystalline alumina.

The abrasive particles can have an average particle size of not greater than about 1050 micrometers. In other embodiments, the average particle size of the abrasive particles can be smaller, such as about not greater than 800 microns, not greater than about 600 microns, not greater than about 400 microns, not greater than about 250 microns, not greater than about 225 microns, not greater than about 200 microns, not greater than about 175 microns, not greater than about 150 microns, or even not greater than about 100 microns. Further, the abrasive particles can have an average particle size of at least about 1 micron, such as at least about 5 microns, at least about 10 microns, at least about 20 microns, at least about 30 microns, or even at least about 50 microns, at least about 60 microns, at least about 70 microns, or even at least about 80 microns. It will be appreciated that the average particle size of the abrasive particles can be within a range between any of the minimum and maximum values noted above.

Further, with respect to abrasive particles utilizing microcrystalline alumina, it is to be understood that microcrystalline alumina can be formed from grains having an average grain size of submicron size. In fact, the average grain size of the microcrystalline alumina can be no greater than about 1 micron, such as no greater than about 0.5 microns, no greater than about 0.2 microns, no greater than about 0.1 microns, no greater than about 0.08 microns, no greater than about 0.05 microns, or even no greater than about 0.02 microns.

In addition, the formation of a mixture comprising abrasive particles and bond material may further include the addition of other components, such as fillers, pore formers, and materials suitable for forming the final shaped bonded abrasive article. Some suitable examples of pore-forming materials include, but are not limited to, foamed alumina, foamed mullite, hollow spheres (including hollow glass spheres, hollow ceramic spheres, or hollow polymer spheres), polymeric or plastic materials, organic compounds, fibrous materials (including glass, ceramic, or polymeric strands or fibers). Other suitable pore-forming materials may include naphthalene, PDB, shells, wood, and the like. In other embodiments, the filler may comprise one or more inorganic materials including, for example, oxides, and may include, inter alia, crystalline or amorphous phases of zirconia, silica, titania, and combinations thereof.

After the mixture is properly formed, the mixture may be shaped. Suitable shaping methods may include pressing operations and/or molding operations, and combinations thereof. For example, in one embodiment, the mixture may be shaped by cold pressing the mixture in a mold to form a green body.

After the green body is properly formed, the green body may be sintered at a particular temperature to facilitate forming an abrasive article having a glass phase bond material. It should be noted that the sintering operation may be performed at a sintering temperature of less than about 1000 ℃. In particular embodiments, the sintering temperature may be less than about 980 ℃, less than about 950 ℃, and particularly in the range of about 800 ℃ to 950 ℃. It will be appreciated that a particularly low sintering temperature may be utilized with the above-described bond components such that excessive temperatures are avoided, thereby limiting the decomposition of the abrasive particles during the forming process.

According to a particular embodiment, the bonded abrasive body comprises a bond material having a glass phase material. In particular instances, the binding material may be a single phase vitreous material.

The final shaped bonded abrasive body can have a particular content of bond material, abrasive particles, and pores. For example, the body of the bonded abrasive article can have at least about 42vol porosity for the total volume of the bonded abrasive body. In other embodiments, the amount of porosity can be greater such that, for example, at least about 43vol, such as at least about 44vol, at least about 45vol, at least about 46vol, at least about 48vol, or even at least about 50vol for the total volume of the bonded abrasive body. According to an embodiment, the bonded abrasive body can have not greater than about 70vol, such as not greater than about 65vol, not greater than about 62vol, not greater than about 60vol, not greater than about 56vol, not greater than about 52vol, or even not greater than about 50vol porosity. The bonded abrasive body can comprise about 46 vol% to about 50 wt% porosity for the total volume of the bonded abrasive body, for example about 46 vol% to about 48 wt% porosity for the total volume of the bonded abrasive body. It is to be understood that the bonded abrasive body can have pores within a range between any of the minimum and maximum percentages noted above.

According to one embodiment, the bonded abrasive body can have at least about 35vol abrasive particles for the total volume of the bonded abrasive body. In other embodiments, the total content of abrasive particles may be greater, such as at least about 37 vol%, or even at least about 39 vol%. According to a particular embodiment, the bonded abrasive body can be formed such that it has not greater than about 50vol abrasive particles, such as not greater than about 48vol, or even not greater than about 46vol, for the total volume of the bonded abrasive body. It is to be understood that the content of abrasive particles in the bonded abrasive body can be within a range between any of the minimum and maximum percentages noted above.

In particular instances, the bonded abrasive body is formed such that it includes a small content (vol%) of bond material compared to the content of pores and abrasive particles. For example, the bonded abrasive body can have not greater than about 15vol bond material for the total volume of the bonded abrasive body. In other cases, the bonded abrasive body can be formed such that it comprises not greater than about 14vol, not greater than about 13vol, or even not greater than about 12vol bond material for the total volume of the bonded abrasive body. In a particular instance, the bonded abrasive body can be formed such that it comprises at least about 7vol, such as at least about 8vol, about at least about 9vol, or even at least about 10vol bond material for the total volume of the bonded abrasive body.

Fig. 1 includes a representation of phases present in a particle bonded abrasive article according to an embodiment. Fig. 1 includes vol% bond material, vol% abrasive particles, and vol% porosity. Shaded region 101 represents a conventional bonded abrasive article suitable for grinding applications, while shaded portion 103 represents the phase content of a bonded abrasive article according to embodiments herein.

It should be noted that the phase content of the conventional bonded abrasive article (i.e., shaded region 101) is significantly different from the phase content of the bonded abrasive article of the embodiment. It should be noted that conventional bonded abrasive articles typically have a maximum porosity in the range of about 40 vol% to 51 vol%, an abrasive grain content of about 42 vol% to 50 vol%, and a bond material content of about 9 vol% to 20 vol%. Conventional bonded abrasive articles typically have a maximum pore content of 50 vol% or less because grinding applications require bonded abrasive bodies of sufficient strength to handle the excessive forces encountered during grinding, and highly porous bonded abrasive bodies have not previously been able to withstand such forces.

According to one embodiment, a bonded abrasive article may have many more pores than conventional bonded abrasive articles. For example, a bonded abrasive article of an embodiment can have a void content in a range from about 51vol to about 58vol for the total volume of the bonded abrasive body. Additionally, as shown in fig. 1, the bonded abrasive article of embodiments has an abrasive particle content in a range of about 40 vol% to about 42 vol% for the total volume of the bonded abrasive article, and a particularly low bond material content in a range of about 2 vol% to about 9 vol%.

It should be noted that bonded abrasive bodies in embodiments herein can have particular characteristics, unlike conventional bonded abrasive bodies. In particular, the bonded abrasive articles herein may have particular amounts of porosity, abrasive particles, and bond material, while exhibiting particular mechanical properties that may make them suitable for particular applications, such as grinding applications. For example, in one embodiment, a bonded abrasive body can have a particular modulus of rupture (MOR), which can correspond to a particular modulus of elasticity (MOE). For example, for a MOE of at least about 40GPa, the bonded abrasive body may have a MOR of at least 45 MPa. In one embodiment, for a MOE of 40GPa, the MOR may be at least about 46MPa, such as at least about 47MPa, at least about 48MPa, at least about 49MPa, or even at least about 50 MPa. Further, for a MOE of 40GPa, the bonded abrasive body can have a MOR of not greater than about 70MPa, such as not greater than about 65MPa, or not greater than about 60 MPa. It will be appreciated that MOR can be within a range between any of the minimum and maximum values noted above.

In another embodiment, the MOR may be at least about 45MPa for certain bonded abrasive bodies having a MOE of 45 GPa. Indeed, for certain bonded abrasive bodies having a MOE of 45GPa, the MOR may be at least about 46MPa, such as at least about 47MPa, at least about 48MPa, at least about 49MPa, or even at least about 50 MPa. Further, for a MOE of 45GPa, the MOR may be not greater than about 70MPa, not greater than about 65MPa, or even not greater than about 60 MPa. It will be appreciated that MOR can be within a range between any of the minimum and maximum values noted above.

MOR can be measured on samples having dimensions of 4 "x 1" x 0.5 "using the standard 3-point bending test, where a load is applied in the 1" x 0.5 "plane, typically according to ASTM D790, with only the sample dimensions being different. The failure load can be documented and the MOR calculated back using standard equations. The MOE may be calculated by measuring the natural frequency of the composite material using a grindononic instrument or similar device, as per standard practice in the abrasive grinding wheel industry.

In one embodiment, the bonded abrasive body can have a strength ratio, which is a measure of MOR divided by MOE. In particular instances, the strength ratio (MOR/MOE) of a particular bonded abrasive body may be at least about 0.8. In other cases, the intensity ratio may be at least about 0.9, such as at least about 1.0, at least about 1.05, at least about 1.10. Further, the intensity ratio can be not greater than about 3.00, such as not greater than about 2.50, not greater than about 2.00, not greater than about 1.70, not greater than about 1.50, not greater than about 1.40, or not greater than about 1.30. It will be appreciated that the strength ratio of the bonded abrasive body can be within a range between any of the minimum and maximum values noted above.

According to one embodiment, the bonded abrasive body may be adapted for a particular grinding operation. For example, the bonded abrasive bodies of the embodiments herein have been found to be suitable for use in grinding operations. In fact, bonded abrasive bodies can be utilized without damaging the workpiece and providing suitable or improved grinding performance.

The grinding ability of the bonded abrasive body referred to herein may relate to grinding operations such as centerless grinding, cylindrical grinding, crankshaft grinding, various surface grinding operations, bearing and gear grinding operations, creep feed grinding, and various tool shop grinding processes. In addition, suitable workpieces for grinding operations may include inorganic or organic materials. In particular instances, the workpiece may comprise a metal, metal alloy, plastic, or natural material. In one embodiment, the workpiece may comprise ferrous metals, non-ferrous metals, metal alloys, metal superalloys, and combinations thereof. In another embodiment, the workpiece may comprise an organic material, including, for example, a polymeric material. In other cases, the workpiece may be a natural material, including, for example, wood.

Some versions of the wheel size of these abrasive articles may vary in diameter from greater than about 4.5 inches to about 54 inches. Typical cut amounts vary from about 0.0001 inch to about 0.500 inch, depending on the application.

In certain instances, it has been noted that bonded abrasive bodies are capable of grinding workpieces at particularly high removal rates. For example, in one embodiment, the bonded abrasive body can have a material removal rate of at least about 0.4 inches³Minute/inch (258 mm)³Per minute/mm) was performed. In other embodiments, the material removal rate may be at least about 0.45 inches³Minute/inch (290 mm)³Per minute/mm), e.g., at least about 0.5 inch³Minute/inch (322 mm)³Per minute/mm) of at least about 0.55 inch³Minute/inch (354 mm)³Per minute/mm), or even at least about 0.6 inch³Minute/inch (387 mm)³In terms of/min/mm). Further, for certain bonded abrasive bodies, the material removal rate can be not greater than about 1.5 inches³Minute/inch (967 mm)³Per minute/mm), such as not greater than about 1.2 inches³Minute/inch (774 mm)³Per minute/mm), no greater than about 1.0 inch³Minute/inch (645 mm)³Per minute/mm), or even no greater than about 0.9 inches³Minute/inch (580 mm)³In terms of/min/mm). It will be appreciated that the bonded abrasive body of the present application can grind a workpiece at a material removal rate within a range between any of the minimum and maximum values noted above.

In certain grinding operations, it has been noted that the bonded abrasive bodies of the present application can grind a particular depth of cut (DOC) or (Zw). For example, the depth of cut achieved by the bonded abrasive body can be at least about 0.003 inches (0.0762 millimeters). In other cases, the bonded abrasive body can achieve a depth of cut of at least about 0.004 inches (0.102 mm), such as at least about 0.0045 inches (0.114 mm), at least about 0.005 inches (0.127 mm), or even at least about 0.006 inches (0.152 mm), during the grinding operation. It is to be understood that the depth of cut for grinding operations utilizing the bonded abrasive bodies herein can be no greater than about 0.01 inches (0.254 mm), or no greater than about 0.009 inches (0.229 mm). It will be appreciated that the depth of cut can be within a range between any of the minimum and maximum values noted above.

In other embodiments, it has been noted that bonded abrasive bodies can grind workpieces at a maximum power of no more than about 10Hp (7.5kW) while using the grinding parameters as previously described. In other embodiments, the maximum power in the grinding operation is no greater than about 9Hp (6.8kW), such as no greater than about 8Hp (6.0kW), or even no greater than about 7.5Hp (5.6 kW).

According to another embodiment, during grinding operations, it has been noted that the bonded abrasive articles of the embodiments herein have superior angular fixturing capabilities, particularly as compared to conventional bonded abrasive articles. In fact, at a depth of cut (Zw) of at least about 1.8, the bonded abrasive body can have an angular fixity factor of not greater than about 0.07 inches, corresponding to 0.00255 inches/sec-arc. It should be noted that as used herein, a depth of cut of 1.0 corresponds to 0.00142 inches/second-arc, and a depth of cut (Zw) of 1.4 corresponds to 0.00198 inches/second-arc. It should be understood that the angle fixing factor is a measure of the change in radius (in inches) after 5 grindings of a workpiece 4330V, which is a NiCrMoV hardened and tempered high strength steel alloy, at a particular depth of cut. In certain other embodiments, the bonded abrasive article exhibits an angular fixity factor of not greater than about 0.06 inch, such as not greater than about 0.05 inch, not greater than about 0.04 inch, for a depth of cut of at least about 1.80.

In one embodiment, an abrasive article may include a bonded abrasive body having abrasive particles contained in a bond material. The bonded abrasive body can comprise an abrasive particle-to-bond material interfacial modulus of elasticity (MOE) of at least about 225 GPa. The bonded abrasive body can be configured to abrade a workpiece comprising metal at a speed of less than about 60 m/s.

For example, the abrasive particle-bond material interface MOE may be at least about 250GPa, such as at least about 275GPa, or even at least about 300 GPa. Alternatively, the abrasive particle-bond material interface MOE can be not greater than about 350GPa, such as not greater than about 325GPa, or even not greater than about 320 GPa.

In another embodiment, an abrasive article can include a bonded abrasive body having abrasive particles contained in a bond material. The bonded abrasive body can comprise an abrasive particle-to-bond material interfacial hardness of at least about 13 GPa. The bonded abrasive body can be configured to abrade a workpiece comprising metal at a speed of less than about 60 m/s. In other embodiments, the abrasive particle-bond material interfacial hardness may be at least about 14GPa, or even at least about 15 GPa. Alternatively, the abrasive particle-bond material interfacial hardness can be not greater than about 20GPa, such as not greater than about 18GPa, or even not greater than about 16 GPa.

In yet another embodiment, the bonded abrasive body can include a surface finish of not greater than about 125 microinches.

The bonded abrasive body can be operated at a feed rate (Z' w) of at least about 1.0 inch/minute. For example, Z' w can be no greater than about 1.4 inches/minute, such as no greater than about 1.8 inches/minute, no greater than about 2.0 inches/minute, or even 2.2 inches/minute.

In one aspect, the bonded abrasive body can comprise at least about 0.235 inches³Material removal rate per minute.

Embodiments of abrasive articles may include a bonded abrasive body having abrasive particles contained in a bond material. The bonded abrasive body can include a varying cut factor defined as a change in x-axis radius relative to a change in feed rate. The grinding factor may be not greater than about 0.040. The bonded abrasive body can be configured to abrade a workpiece comprising metal at a speed of less than about 60 m/s. The grinding factor can be not greater than about 0.035, such as not greater than about 0.030, or even not greater than about 0.028.

In a particular embodiment, the bonded abrasive body can include an x-axis angular fixity factor of not greater than about 0.080 inches. For example, the x-axis angle fixation factor may be not greater than about 0.070 inches, such as not greater than about 0.060 inches, not greater than about 0.050 inches, or even not greater than about 0.042 inches.

The angle fixing factor may be expressed as a percentage change in wheel radius. For example, for a 7 inch diameter (i.e., 3.5 inch radius) wheel, a fixed x-axis angle factor of 0.080 inches indicates a 2.3% change in the x-axis radius of the wheel of 1- (3.5-0.08)/3.5. The change in the x-axis radius of the wheel was 2%, 1.7%, 1.4% and 1.2% for x-axis angle fixation factors of 0.07, 0.06, 0.05 and 0.042, respectively. Thus, the bonded abrasive body can have an x-axis radius variation of no greater than 3%. For example, the nodal abrasive body can have a change in x-axis radius of no greater than 2.5%, such as no greater than about 2%, no greater than about 1.7%, no greater than about 1.5%, or even no greater than about 1.3%.

Other embodiments of bonded abrasive bodies can include a grinding factor defined as the change in y-axis radius as a function of feed rate. The grinding factor may be not greater than about 0.018. Other examples of grinding factors may be no greater than about 0.016, such as a grinding factor of no greater than about 0.014, a grinding factor of no greater than about 0.012, or even a grinding factor of no greater than about 0.010.

In a particular embodiment, the bonded abrasive body can include a y-axis angular fixity factor of not greater than about 0.033 inches, such as not greater than about 0.030 inches, not greater than about 0.025 inches, or even not greater than about 0.024 inches.

The angle fixing factor may be expressed as a percentage change in wheel radius. For example, for a 7 inch diameter (i.e., 3.5 inch radius) wheel, a fixed y-axis angle factor of 0.033 inches indicates a change in the y-axis radius of the wheel of 1- (3.5-0.033)/3.5 of 0.94%. The x-axis radius of the wheel varied by 0.86%, 0.71%, and 0.69% for y-axis angle fixation factors of 0.03, 0.025, and 0.024, respectively.

Thus, the bonded abrasive body can have a y-axis radius variation of not greater than about 1%. For example, the bonded abrasive body can have an x-axis radius variation of no greater than 0.9%, such as no greater than about 0.8%, or even no greater than about 0.7%.

Other versions of the abrasive article may include a body requiring at least about 3% less dressing than a conventional OD abrasive grinding wheel, such as at least about 4%, at least about 5%, or even at least about 6% less dressing than a conventional OD abrasive grinding wheel.

In other embodiments, the body may require at least about 5% less cycle time than a conventional OD abrasive grinding wheel. For example, the body may require at least about 10% less cycle time than a conventional OD abrasive grinding wheel, such as at least about 15% less, or even at least about 18% less cycle time.

Embodiments of abrasive articles can have a bonded abrasive body that can be configured to abrade a workpiece comprising metal at a velocity of less than about 55 m/s. For example, the velocity may be less than about 50m/s, such as less than about 45m/s, or even less than about 40 m/s. In still other aspects, the velocity can be at least about 35m/s, such as at least about 40m/s, at least about 45m/s, or even at least about 50m/s.

The abrasive article may have a body including a wheel having an outer diameter in the range of about 24 inches to about 30 inches, for example, an outer diameter of about 18 inches to about 30 inches, about 10 inches to about 36 inches, or even about 5 inches to about 54 inches.

Other embodiments of the abrasive article may include a bond material comprising a single phase vitreous material. Some aspects of the bonded abrasive body can include at least about 42vol porosity, for example, not greater than about 70vol porosity, for the total volume of the bonded abrasive body.

The bonded abrasive body can include at least about 35vol abrasive particles for the total volume of the bonded abrasive body. In other embodiments, the bonded abrasive body can include not greater than about 15vol bond material for the total volume of the bonded abrasive body.

Examples of the bond material may be formed from not greater than about 20 wt% boron oxide (B) based on the total weight of the bond material₂O₃) And (4) forming. In other aspects, the bond material can include not greater than about 3.2 silicon dioxide (SiO)₂) Weight percent and alumina (Al)₂O₃) Ratio of (a) to (b) (SiO)₂∶Al₂O₃). The bond material may be composed of not greater than about 3.0 wt% phosphorus pentoxide (P)₂O₅) And (4) forming. Or,the binder material may be substantially free of phosphorus pentoxide (P)₂O₅)。

Other embodiments of the bond material may be formed from an alkaline earth metal oxide compound (RO). For example, the total amount of alkaline earth oxide compounds (RO) present in the bond material may be no greater than about 3.0 wt%. The bond material may be formed of not greater than about 3 alkaline earth oxide compounds (RO) selected from the group consisting of calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), and strontium oxide (SrO). The binder material may also comprise a material selected from lithium oxide (Li)₂O), sodium oxide (Na)₂O), potassium oxide (K)₂O) and cesium oxide (Cs)₂O) and alkali metal oxide compounds (R) of combinations thereof₂O). The binder material may be composed of a total of no greater than about 20 wt% alkali metal oxide compounds (R)₂O) is formed. Alternatively, the bond material can include no greater than about 3 alkali metal oxide compounds (R)₂O). In other embodiments, the amount (wt%) of any one of the alkali metal oxide compounds present in the bond material may be no greater than half of the total amount (wt%) of alkali metal oxide.

In still other embodiments, the bond material may be composed of no greater than about 55 wt% silicon dioxide (SiO)₂) And (4) forming. The bond material may be composed of at least about 12 wt% alumina (Al)₂O₃) And (4) forming. The binder material may be composed of at least one alkali metal oxide compound (R)₂O) and at least one alkaline earth metal oxide compound (RO), wherein the total content of alkali metal oxide compound and alkaline earth metal oxide compound is no greater than about 20 wt.%.

Some embodiments of the bond material may be formed from boron oxide (B)₂O₃) And silicon dioxide (SiO)₂) Wherein the total content of boron oxide and silicon dioxide may be no greater than about 70 wt%. Content of Silica (SiO)₂) May be greater than the boron oxide content.

In one particular embodiment, the binder material may be formed from a composition comprising not greater than about 1 wt% of a material selected from MnO₂、ZrSiO₂、CoAl₂O₄And MgO oxide compoundThe composition of (a). The binder material may be formed substantially free of materials selected from MnO₂、ZrSiO₂、CoAl₂O₄And an oxide compound of MgO. Additionally, the bonded abrasive body can be sintered at a temperature of not greater than about 1000 ℃.

Embodiments of the bond material may include about 2.4 to about 3.5 silicon dioxide (SiO)₂) Weight percent and alumina (Al)₂O₃) Ratio of weight percents (SiO)₂∶Al₂O₃). The binder material may include trace amounts (< 1%) of Fe₂O₃、TiO₂And Mg each or a combination thereof. The bond material can include about 32 to about 52 silicon dioxide (SiO)₂) Ratio of weight percent to weight percent CaO (SiO)₂CaO). The bond material may also include about 9.6 to about 26 silicon dioxide (SiO)₂) Weight percent and Li₂Ratio of O in weight percent (SiO)₂∶Li₂O). In another embodiment, the bond material can include about 4.8 to about 10.4 silicon dioxide (SiO)₂) Weight percent of Na₂Ratio of O in weight percent (SiO)₂∶Na₂O). The bond material can include about 9.6 to about 26 silicon dioxide (SiO)₂) Weight percent and K₂Ratio of O in weight percent (SiO)₂∶K₂O). The bond material may also include about 2.8 to about 5.2 silicon dioxide (SiO)₂) Weight percent and B₂O₃Ratio of (a) to (b) (SiO)₂∶B₂O₃)。

Embodiments of the bond material may include about 10 to about 20 alumina (Al)₂O₃) Ratio of weight percent to weight percent CaO (Al)₂O₃CaO). The bond material may include about 3 to about 10 alumina (Al)₂O₃) Weight percent and Li₂Ratio of O weight percent (Al)₂O₃∶Li₂O). The bond material may also include about 1.5 to about 4 alumina (Al)₂O₃) Weight percent of Na₂Ratio of O weight percent (Al)₂O₃∶Na₂O). One embodiment of the bond material may include about 3 to about 10 alumina (Al)₂O₃) Weight percent and K₂Ratio of O weight percent (Al)₂O₃∶K₂O). The bond material may also include about 0.9 to about 2 alumina (Al)₂O₃) Weight percent and B₂O₃Ratio of weight percent (Al)₂O₃∶B₂O₃)。

In other embodiments, the binder material may include a weight percent of CaO to Li of about 0.2 to about 0.75₂Ratio of O weight percent (CaO: Li)₂O). The binder material may include CaO and Na in an amount of about 0.1 to about 0.3 weight percent₂The ratio of the weight percent of O (CaO: Na)₂O). The binder material may also include a weight percent of CaO and K of about 0.2 to about 0.75₂Ratio of O weight percent (CaO: K)₂O). Additionally, the binder material may include a weight percent of CaO of about 0.16 to about 0.15 with B₂O₃Weight percent ratio (CaO: B)₂O₃)。

Other embodiments of the bonding material may include from about 0.2 to about 1 Li₂O weight percent and Na₂Ratio of O weight percent (Li)₂O∶Na₂O). The binder material may include about 0.4 to about 2.5 Li₂O weight percent and K₂Ratio of O weight percent (Li)₂O∶K₂O). The binder material may also include about 0.12 to about 0.5 Li₂O weight percent and B₂O₃Ratio of weight percents (Li)₂O∶B₂O₃)。

One particular embodiment of the binder material may include from about 1 to about 5 Na₂O weight percent and K₂Ratio of O weight percent (Na)₂O∶K₂O). The binder material may also include about 0.3 to about 1 Na₂O weight percent and B₂O₃Ratio of weight percents (Na)₂O∶B₂O₃). Additionally, the bonding material may comprise from about 0.12 to about 0.5K of₂O weight percent and B₂O₃Ratio of weight percents (K)₂O∶B₂O₃)。

Other embodiments of abrasive articles can include a bonded abrasive body having abrasive particles contained in a bond material consisting of: not greater than about 20 wt% boron oxide (B)₂O₃) Having not greater than about 3.2 (in weight percent) silicon dioxide (SiO)₂) The weight percentage is as follows: alumina (Al)₂O₃) A ratio of weight percent, and not greater than about 3.0 wt% phosphorus pentoxide (P)₂O₅) Wherein the bonded abrasive body has at least about 42 vol% porosity for the total volume of the bonded abrasive body. The bonded abrasive body is capable of grinding a workpiece comprising metal at a speed of less than about 60 m/s.

Embodiments of a method of grinding an abrasive article may include forming a bonded abrasive body having abrasive particles contained in a bond material such that the bonded abrasive body comprises an abrasive particle-bond material interfacial modulus of elasticity (MOE) of at least about 225 GPa. The method can include abrading a workpiece comprising metal with a bonded abrasive body at a speed of less than about 60 m/s.

Another embodiment of a method of grinding an abrasive article may include forming a bonded abrasive body having abrasive particles contained within a bond material such that the bonded abrasive body comprises an abrasive particle-bond material interfacial hardness of at least about 13 GPa. The method can include abrading a workpiece comprising metal with a bonded abrasive body at a speed of less than about 60 m/s.

Yet another embodiment of a method of grinding an abrasive article may include forming a bonded abrasive body having abrasive particles contained in a bond material such that the bonded abrasive body comprises a grinding factor defined as a change in x-axis radius as a function of feed rate and the grinding factor is not greater than about 0.040 for a feed rate (Z' w) of at least about 1.0 inch/minute. The method can include abrading a workpiece comprising metal with a bonded abrasive body at a speed of less than about 60 m/s.

The method of grinding an abrasive article can further comprise forming a bonded abrasive body having abrasive particles contained in a bond material such that the bonded abrasive body comprises a grinding factor defined as a change in y-axis radius as a function of in-feed rate and the grinding factor is not greater than about 0.018 for an in-feed rate (Z' w) of at least about 1.0 inches/minute. The method can include abrading a workpiece comprising metal with a bonded abrasive body at a speed of less than about 60 m/s.

Yet another method of grinding an abrasive article can include a bonded abrasive body having abrasive particles contained in a bond material, the bond material consisting of: not greater than about 20 wt% boron oxide (B)₂O₃) Having not greater than about 3.2 (in weight percent) silicon dioxide (SiO)₂) The weight percentage is as follows: alumina (Al)₂O₃) A ratio of weight percent, and not greater than about 3.0 wt% phosphorus pentoxide (P)₂O₅) Wherein the bonded abrasive body has at least about 42 vol% porosity for the total volume of the bonded abrasive body. The method can include abrading a workpiece comprising metal with a bonded abrasive body at a speed of less than about 60 m/s.

Examples

Example 1

The life or performance of a grinding wheel in OD grinding applications may depend on the number of grindings that it can withstand, or the number of parts that the grinding wheel can grind before losing its shape or angular fixturing ability, which also affects the quality of the parts. The life of the grinding wheel may also be related to the frequency of dressing required to produce a fresh surface for subsequent grinding operations. The form retention or angle retention capability of the wheel may also be related to the ability of the bond material to retain the grains and retain the advantages of its effective grinding operation. In this example, abrasive wheels with 38A fused alumina abrasive grains containing different bond materials were tested. The testing device is an MTS nanoindenter XP and utilizes a Berkovich type indenter. For each sample, indentation was performed at 20 locations along double lines (see fig. 2), extending from the abrasive grain through the grain boundaries to the bond material area and then into the next abrasive grain. The indentations in the rows were spaced 10 microns apart, with a distance of 10 microns between rows. The indentation was performed to a depth of 1 micron.

Fig. 3 and 4 depict a comparison of the modulus of elasticity (MOE) and hardness for three different binding materials, respectively. Lines 1301, 1302, and 1303 represent the MOEs of the abrasive particles, bond material, and abrasive particle-bond material interfaces, respectively, for samples of bonded abrasive articles formed according to embodiments herein. The sample has a bond material content range of about 7 vol% to about 12 vol% for the total volume of the bonded abrasive body. Additionally, the sample has a porosity range of about 46 vol% to about 50 vol% for the total volume of the bonded abrasive body.

In fig. 3, first conventional sample CS1 produced MOE values of 1305, 1306 and 1307 for its abrasive particle, bond material and abrasive particle-bond material interface, respectively. Sample CS1 is a bonded abrasive article commercially available as the VS product from Saint Gobain Corporation. The second conventional sample, CS2, is a bonded abrasive article commercially available from Saint Gobain Corporation as the VH product. Sample CS2 produced MOE values for 1310, 1311, and 1312 for its abrasive particles, bond, and abrasive particle-bond interfaces, respectively.

As shown in fig. 3, the interfacial MOE 1303 of the embodiment significantly surpassed the interfacial MOEs 1307 and 1312 of the conventional samples CS1 and CS2, respectively. Such results show that the abrasive particle-bond material interface MOE of a bonded abrasive article formed according to embodiments herein is a significant improvement over conventional bonded abrasive articles of the prior art.

In fig. 4, lines 1401, 1402, and 1403 represent the hardness of the abrasive particles, bond material, and abrasive particle-bond material interface, respectively, for a sample of bonded abrasive articles formed according to the embodiment of fig. 3. The first conventional sample CS1 produced hardness values for 1405, 1406, and 1407, respectively, for its abrasive particles, bond material, and abrasive particle-bond material interface. Sample CS1 was the same as disclosed above in fig. 3. Similarly, second conventional sample CS2 produced hardness values for its abrasive particles, bond material, and abrasive particle-bond material interface of 1410, 1411, and 1412, respectively. Sample CS2 was the same as disclosed above in fig. 3.

As illustrated in fig. 4, the interfacial hardness 1403 of the embodiment significantly surpassed the interfacial hardnesses 1407 and 1412 of conventional samples CS1 and CS2, respectively. Such results show that the hardness of the abrasive particle-bond material interface of a bonded abrasive article formed according to embodiments herein is significantly improved over conventional bonded abrasive articles of the prior art.

Thus, the new bonding material has a higher modulus and hardness. This is particularly noticeable for the weaker components (bond material and interface) in the grinding wheel. The improvement in modulus and hardness of the interface can help to strengthen the interface and show better attachment to the abrasive particles. These designs are intended to improve the life of the grinding wheel under harsh grinding conditions.

Example 2

For this angle fixing application and test, 47 inch wheel samples were prepared. The 4 samples included 3 conventional binder materials and 1 binder material according to embodiments herein. All 4 samples included 38A fused alumina grains, and each included a bond material content of about 7 vol% to about 12 vol%, and a porosity of about 46% to about 50%, based on the total volume of the bonded abrasive body. The conventional samples used the same VS and VH binder materials as used in example 1. Table 1 contains more detailed information for the test conditions used in example 2.

TABLE 1

The 4 samples were tested in an angle-fixed configuration on a Bryant grinder. The grinding wheel speed was 50.36 m/s. The test material was 3.745 inch OD 4330V steel (R)_c28-32). The speed of the test material was 1.15 m/s. The grinding mode is 0.100Inch wide ground outer cut. Each wheel was dressed with a reverse diamond coated roller. The feed rate was adjusted to give 1.0, 1.4 and 1.8 inches³Target material removal rate per minute per inch (Z' W). 5 consecutive radius grindings without dressing were performed on each test wheel at the target feed rate. Surface finish and unevenness are obtained from the work material after the last grinding. After each grinding, for the corner radius and radial wear tests, a test wheel was used to grind a Formica blank that describes the profile of the wheel. Measurements were obtained from the blanks.

Fig. 6 includes a line of surface finish Ra versus feed rate (Z' w) for 3 conventional bonded abrasive articles 1600, 1601, and 1602 and embodiment bonded abrasive article 1605. The bonded abrasive body 1605 of an embodiment comprises a surface finish of not greater than about 85 micro-inches at a feed rate (Z' w) of 1.4 inches/minute. In contrast, articles 1600, 1601, and 1602 all exhibited a surface finish of at least about 125 microinches at a feed rate (Z' w) of 1.4 inches/minute.

Fig. 7 includes a plot of material removal versus feed rate (Z' w) for 5 passes of 3 conventional bonded abrasive articles 1700, 1701, and 1702 and bonded abrasive article 1705 of the embodiments. Bonded abrasive body 1705 comprises at least about 0.241 inches at a feed rate (Z' w) of 1.8 inches/minute³Material removal rate per minute. In contrast, the conventional articles 1700, 1701, and 1702 all exhibit a feed rate (Z' w) of no greater than about 0.235 inch at 1.8 inches/minute³Material removal rate per minute.

A schematic diagram of changes in angular wear or radius measurements is shown in fig. 5. Dimension 1500 represents the original dimension of the sample along the x-axis (i.e., an axial width of 0.875 inches), while dimension 1501 represents the post-grind dimension of the sample along the x-axis. Similarly, dimension 1502 represents the original dimension of the sample along the y-axis (i.e., 7 inches in diameter), while dimension 1503 represents the ground dimension of the sample along the y-axis.

Fig. 8 includes a graph illustrating the change in x-axis radius of the angular fixing factor with respect to feed rate (Z' w) for the same 3 conventional bonded abrasive articles 1800, 1801, and 1802, and embodiment bonded abrasive article 1805. The bonded abrasive body 1805 of an embodiment includes an x-axis angular fixation factor of about 0.042 inches at a feed rate (Z' w) of 1.8 inches/minute. In contrast, conventional articles 1800, 1801, and 1802 all exhibit an x-axis angular fixation factor of at least about 0.080 inches at a feed rate (Z' w) of 1.8 inches/minute.

Additionally, bonded abrasive body 1805 includes a grinding factor defined as a change in x-axis radius as a function of feed rate. The grinding factor is essentially the average slope of the lines in fig. 8. For example, for body 1805, the numerator of the grinding factor is 0.042-0.019 ═ 0.023. The denominator is 1.80-1.00 ═ 0.80. 0.023/0.80-grinding factor is about 0.029. In contrast, articles 1800, 1801, and 1802 have a grinding factor of at least about 0.050.

Similarly, fig. 9 includes a graph illustrating the change in the y-axis radius of the angular fixing factor relative to the feed rate (Z' w) for the same 3 conventional bonded abrasive articles 1900, 1901, and 1902 and the bonded abrasive article 1905 of the embodiment. Body 1905 exhibits a y-axis angle fixation factor of about 0.024 inches at a feed rate (Z' w) of 1.8 inches/minute. Articles 1900, 1901, and 1902 have a y-axis angular fixation factor of at least about 0.033 inches at a feed rate (Z' w) of 1.8 inches/minute.

The grinding factor is also calculated based on fig. 9. For example, for body 1905, the grinding factor has a numerator of 0.024-0.016 ═ 0.008. The denominator is 1.80-1.00 ═ 0.80. The grinding factor is about 0.01 at 0.008/0.80. In contrast, articles 1900, 1901, and 1902 have a grinding factor of at least about 0.0188.

Thus, the variation of the corner radius along both the x-axis and the y-axis shows that products with the bonding material according to embodiments herein exhibit minimal angular wear at all material removal rates compared to products made from conventional bonding systems.

Example 3

In this example, an embodiment including a combination of sol gel and fused alumina abrasive particles was formed with the bond material described above for the above example. This sample was tested in a centerless plunge application to finish profile, in contrast to a product having a combination of sol gel and fused alumina abrasive particles and the conventional bond material VH previously used in other examples. The grinding wheel had a 16 inch diameter and the material ground was mild steel (1014). The goal is to improve productivity by increasing the parts per dressing. The wheel speed was 57.45 m/sec and the part speed was 1.15 m/sec.

Table 2 contains more detailed information for the test conditions used in example 3.

TABLE 2

Fig. 10 includes a chart of parts per dressing for a conventional bonded abrasive article 2000 and a bonded abrasive article 2005 of an embodiment. Article 2005 showed significantly improved parts per finish (about 7% improvement) as well as good surface finish or shape compared to article 2000.

Another advantage observed is that the feed rate can be increased significantly for a new sand wheel, which facilitates a reduction in cycle time. The reduced cycle time is more efficient in grinding operations. The cycle times were tested on the same samples described in fig. 10 and the results are shown in fig. 11. Fig. 11 is a graph of cycle time for a conventional bonded abrasive article 2100 and an embodiment bonded abrasive article 2105. Article 2105 shows a significant improvement (about 18%) over article 2100.

The foregoing embodiments relate to abrasive products, and more particularly, to bonded abrasive products that exhibit departures from the prior art. The bonded abrasive products of the embodiments herein utilize a combination of features that facilitate improved grinding performance. As described herein, bonded abrasive bodies of embodiments herein utilize a particular amount and type of abrasive particles, a particular amount and type of bond material, and a particular amount of porosity. In addition to the discovery that these products can be effectively formed, although in the known art of conventional abrasive products in terms of grade and structure, such products have also been found to exhibit improved grinding performance. It should be noted that the bonded abrasives of embodiments of the present invention, while having significantly higher porosity than conventional grinding wheels, are found to be capable of operating at low speeds during grinding operations. Indeed, it is highly unexpected that the bonded abrasive bodies of the embodiments herein exhibit the ability to operate at wheel speeds of less than about 60m/s while also exhibiting improved material removal rates, improved angular fixturing capabilities, and suitable surface finishes as compared to prior art grinding wheels.

In the foregoing, reference to specific embodiments and the connection of certain components is illustrative. It is to be understood that references to components being joined or connected are intended to disclose direct connections between the components or indirect connections through one or more intervening components as would be understood by practicing the methods discussed herein. Accordingly, 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 construed 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 is provided to comply with patent statutes 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, 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 of the features of any of the disclosed embodiments. Thus, the following claims are hereby incorporated into the detailed description, with each claim standing on its own as defining separately claimed subject matter.

Claims

1. An abrasive article, comprising:

a bonded abrasive body having abrasive particles contained in a bond material;

wherein the bonding material comprises: alkali metal oxide compound (R)₂O) and an alkaline earth metal oxide compound (RO), the total content of the combination being at least 14 wt. -%, based on the total weight of the bond material; and is

Wherein the bonding material comprises: an oxidation content of at least 11 wt% and not more than 17 wt% based on the total weight of the binder materialBoron (B)₂O₃)。

2. The abrasive article of claim 1, wherein the bonded abrasive body comprises an abrasive particle-to-bond material interfacial hardness of at least 13 GPa.

3. The abrasive article of claim 1, wherein the bonded abrasive body is configured to grind a workpiece comprising metal at a speed of at least 35 m/s.

4. The abrasive article of claim 1, wherein the bonded abrasive body comprises at least 42 vol% to 70 vol% porosity for the total volume of the bonded abrasive body, and the bonded abrasive body comprises at least 35 vol% abrasive particles for the total volume of the bonded abrasive body.

5. The abrasive article of claim 1, wherein the bond material comprises at least one alkali metal oxide compound (R)₂O) and at least one alkaline earth metal oxide compound (RO), wherein the total content of the alkali metal oxide compound and the alkaline earth metal oxide compound is not more than 20 wt.%.

6. The abrasive article of claim 1, wherein the Silica (SiO) in the bond material₂) Weight percent and Li₂Ratio of O weight percent (SiO)₂:Li₂O) is 9.6 to 26.

7. The abrasive article of claim 1, wherein the Silica (SiO) in the bond material₂) Weight percent of Na₂Ratio of O weight percent (SiO)₂:Na₂O) is 4.8 to 10.4.

8. The abrasive article of claim 1, wherein the tackSilicon dioxide (SiO) in junction materials₂) Weight percent and K₂Ratio of O weight percent (SiO)₂:K₂O) is 9.6 to 26.

9. The abrasive article of claim 1, wherein the Silica (SiO) in the bond material₂) Weight percent and B₂O₃Ratio of weight percents (SiO)₂:B₂O₃) Is 2.8 to 5.2.

10. The abrasive article of claim 1, wherein Li in the bond material₂O weight percent and Na₂Ratio of O weight percent (Li)₂O:Na₂O) is 0.2 to 1.

11. The abrasive article of claim 1, wherein Li in the bond material₂O weight percent and K₂Ratio of O weight percent (Li)₂O:K₂O) is 0.4 to 2.5.

12. The abrasive article of claim 1, wherein the bond material is Na₂O weight percent and K₂Ratio of O weight percent (Na)₂O:K₂O) is 1 to 5.

13. The abrasive article of claim 1, wherein the bonded abrasive body comprises a grinding factor defined as a change in x-axis radius versus change in feed rate, and the grinding factor is not greater than 0.040 for a feed rate (Z' w) of at least 1.0 inches/minute.

14. The abrasive article of claim 1, wherein the bonded abrasive body comprises a cut factor defined as a change in y-axis radius versus a change in feed rate, and the cut factor is not greater than 0.018 for a feed rate (Z' w) of at least 1.0 inches/minute.

15. The abrasive article of claim 1, wherein the bond material comprises not greater than 20wt boron oxide (B)₂O₃) And comprises silicon dioxide (SiO)₂) And alumina (Al)₂O₃) Wherein silicon dioxide (SiO)₂): alumina (Al)₂O₃) Is not more than 3.2, and comprises not more than 3.0 wt% of phosphorus pentoxide (P)₂O₅) And wherein the bonded abrasive body has at least 42 vol% porosity for the total volume of the bonded abrasive body.