JP2015521963A - Abrasive articles for slower grinding operations - Google Patents

Abstract

The abrasive article includes a bonded abrasive body having abrasive particles contained within the binding material. The bonded abrasive body may include an elastic modulus (MOE) of the interface between the abrasive particles and the bonding material 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. [Selection] Figure 1

Description

  The following is directed to abrasive articles and in particular to bonded abrasive articles suitable for performing grinding operations at lower speeds.

  Abrasive tools are generally formed with abrasive grains contained within a bonding material for material removal applications. Seeded (and not seeded) sintered sol-gel alumina, also referred to as superabrasive abrasive (eg, diamond or cubic boron nitride (CBN)), or microcrystalline alpha alumina (MCA) abrasive Abrasive grains can be used in such polishing tools. The binding material can be an organic material such as a resin or an inorganic material such as glass or glassy material. In particular, bonded abrasive tools that use glassy bonded materials and contain MCA abrasive grains or superabrasive grains are commercially useful for grinding.

  Certain bonded abrasive tools, particularly those that utilize glassy bonding materials, often require a high temperature formation process above about 1100 ° C., which can adversely affect the abrasive grains of the MCA. Indeed, at such high temperatures required to form the polishing tool, the bonding material can react with the abrasive grains, particularly the MCA abrasive grains, which can impair the integrity of the abrasive, and the sharpness of the abrasive grains and It has been recognized that it degrades performance characteristics. As a result, the industry has moved to reduce the formation temperature necessary for forming the bonding material in order to suppress high temperature degradation of the abrasive grains during the formation process. The industry continues to seek to improve the performance of such bonded abrasive articles.

The present disclosure may be better understood with reference to the accompanying drawings, and numerous features and advantages thereof will be apparent to those skilled in the art.
2 is a chart of percent porosity, percent abrasive, and percent binder for prior art bonded abrasive articles and abrasive articles according to embodiments. 3 is a photograph illustrating the elastic modulus and hardness test of abrasive grains, binders, and their interfaces. 2 is a graph of the elastic modulus (MOE) of an abrasive, a binder, and an abrasive-binder interface, comparing two conventional bonded abrasive articles with a bonded abrasive article according to one embodiment herein. 2 is a graph of abrasive, binder, and abrasive-binder interface hardness comparing two conventional bonded abrasive articles to a bonded abrasive article according to one embodiment herein. 2 is a schematic view of an abrasive article showing shape loss along both the x-axis and the y-axis. FIG. FIG. 2 is a diagram of surface finish Ra versus feed rate (Z′w) for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment. FIG. 3 is a diagram of material removal at a 5 times grinding versus feed rate (Z′w) for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment. FIG. 4 is a diagram of x-axis radius change versus feed rate (Z′w) showing corner retention factors for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment. FIG. 4 is a diagram of change in y-axis radius versus feed rate (Z′w) showing corner retention factors for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment. 2 is a graph of the number of parts per dressing for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment. 2 is a cycle time graph for a conventional bonded abrasive article and a bonded abrasive article according to one embodiment. The use of the same symbols in different drawings indicates similar or identical items.

  The following is directed to bonded abrasive articles that may be suitable for workpiece grinding and forming. In particular, the bonded abrasive articles of the embodiments herein can incorporate abrasive particles within the vitreous bonding material. Applications suitable for using the bonded abrasive articles of the embodiments herein include, for example, centerless grinding, cylindrical grinding, crankshaft grinding, various surface grinding operations, bearing and gear grinding operations, creep feed grinding, and Grinding operations include various tool room applications.

According to one embodiment, the method of forming a bonded abrasive article of one embodiment can begin by forming a suitable compound and component mixture to form a bonding material. The binder can be formed of a compound of an inorganic material such as an oxide compound. For example, one suitable oxide material includes silicon oxide (SiO ₂ ). According to one embodiment, the bonding material can be formed from about 55 wt% or less silicon oxide, based on the total weight of the bonding material. In other embodiments, the silicon oxide content can be less, such as about 54 wt% or less, about 53 wt% or less, about 52 wt% or less, or even about 51 wt% or less. Further, in certain embodiments, the binding material is at least about 47%, such as at least about 47%, such as at least about 47%, at least about 48%, or even at least about 49% by weight relative to the total weight of the binding material. At least about 45% by weight silicon oxide. It will be appreciated that the amount of silicon oxide can be within the range of any of the minimum and maximum percentages described above.

The binding material can also incorporate a content of aluminum oxide (Al ₂ O ₃ ). For example, the bonding material can include at least about 12 wt% aluminum oxide, based on the total weight of the bonding material. In other embodiments, the amount of aluminum oxide can be at least about 14%, at least about 15%, or even at least about 16% by weight. In certain instances, the binding material is in an amount of about 23 wt% or less, about 21 wt% or less, about 20 wt% or less, about 19 wt% or less, or even about 18 wt% or less based on the total weight of the binder. Of aluminum oxide. It will be appreciated that the amount of aluminum oxide can be within the range of any of the minimum and maximum percentages described above.

  In certain instances, the bonding material can be formed from a specific ratio of the amount of silicon oxide as measured by weight percent and the amount of aluminum oxide as measured by weight percent. For example, the ratio of silica to alumina can be described by dividing the weight percent of silicon oxide in the bonding material by the weight percent of aluminum oxide. According to one embodiment, the ratio of silicon oxide to aluminum oxide can be about 3.2 or less. In other cases, the ratio of silicon oxide to aluminum oxide in the bonding material can be about 3.1 or less, about 3.0 or less, or even about 2.9 or less. Further, the bonding material may in some instances have a ratio of weight percent silicon oxide to weight percent aluminum oxide of at least about 2.4, at least about 2.5, at least about 2.6, or even at least about 2. At least about 2.2, such as at least about 2.3, such as a degree of 7. It will be appreciated that the total amount of aluminum oxide and silicon oxide can be within the range of any of the minimum and maximum values described above.

According to one embodiment, the bonding material can be formed from a content of boron oxide (B ₂ O ₃ ). For example, the bonding material can incorporate up to about 20% by weight boron oxide, based on the total weight of the bonding material. In other instances, the amount of boron oxide can be less, such as about 19% or less, about 18% or less, about 17% or less, or even about 16% or less. Further, the bonding material may be formed from at least about 11 wt% boron oxide, such as at least about 12 wt%, at least about 13 wt%, or even at least about 14 wt%, based on the total weight of the bonding material. it can. It will be appreciated that the amount of boron oxide can be within the range of any of the minimum and maximum percentages described above.

  According to one embodiment, the bonding material has a total content (ie, total) of weight percent boron oxide and weight percent silicon oxide in the bonding material of about 70% by weight, based on the total weight of the bonding material. It can be formed so that it can be as follows. In other cases, the total content of silicon oxide and boron oxide can be about 69 wt% or less, such as about 68 wt% or less, about 67 wt% or less, or even about 66 wt% or less. According to one particular embodiment, the total weight percent content of silicon oxide and boron oxide is at least about 58% by weight, at least about 60% by weight, at least about 62% by weight, based on the total weight of the binding material, It can be at least about 55 wt%, such as about 63 wt%, at least about 64 wt%, or even at least about 65 wt%. It will be appreciated that the total weight percent of silicon oxide and boron oxide in the binding material can be within the range of any of the minimum and maximum percentages described above.

  Further, in certain instances, the amount of silicon oxide can be greater than the amount of boron oxide in the bonding material when measured in weight percent. In particular, the amount of silicon oxide is at least about 1.5 times greater, at least about 1.7 times greater, at least about 1.8 times greater, at least about 1.9 times greater, and at least about 2 greater than the amount of boron oxide. 0.0 times more, and at least about 2.5 times more. Further, in one embodiment, the bonding material may include an amount of silicon oxide that is no more than about 5 times, such as no more than about 4 times, no more than about 3.8 times, no more than about 3.5 times, etc. It will be appreciated that the difference in the amount of silicon oxide as compared to the amount of boron oxide can be within the range of any of the aforementioned minimum and maximum values.

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

  According to one embodiment, the bonding material can be formed from a total content of alkali oxide compounds of no more than about 20% by weight, based on the total weight of the bonding material. For other bonded abrasive articles according to embodiments herein, the total alkali oxide compound content is about 19% or less, about 18% or less, about 17% or less, about 16% or less, and even more It can be about 15% by weight or less. Further, in one embodiment, the total content of alkali oxide compounds in the bonding material is at least about 10% by weight, such as at least about 12% by weight, at least about 13% by weight, or even at least about 14% by weight. be able to. It will be appreciated that the binding material can include a total content of alkali oxide compounds within any of the minimum and maximum percentages described above.

According to one particular embodiment, the bonding material can be formed from no more than about 3 distinct alkali oxide compounds (R ₂ O), as described above. Indeed, some bonding materials may incorporate no more than about two alkali oxide compounds within the bonding material.

  Furthermore, the binding material can be formed such that the individual content of any of the alkali oxide compounds is no more than half of the total content (weight percent) of the alkali oxide compound in the binding material. Further, according to one particular embodiment, the amount of sodium oxide can be greater than the lithium oxide or potassium oxide content (weight percent). In more specific cases, the total content of sodium oxide as measured by weight percent can be greater than the sum of lithium oxide and potassium oxide content as measured by weight percent. Furthermore, in one embodiment, the amount of lithium oxide can be greater than the content of potassium oxide.

  According to one embodiment, the total amount of alkali oxide compound, as measured by weight percent, that forms the binding material may be less than the amount of boron oxide (as measured by weight percent) in the binding material. it can. Indeed, in certain instances, the total weight percent of the alkali oxide compound as compared to the total weight percent of boron oxide in the bonding material is in the range of about 0.9 to 1.3, and even about 0.9. Can be in the range of about 0.9 to 1.5, such as in the range of about 1.1.

  The binding material can be formed from an amount of alkaline earth compound (RO), where R represents an element from an element of Group IIA of the Periodic Table of Elements. For example, the binding material can incorporate alkaline earth oxide compounds such as calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), and even strontium oxide (SrO). According to one embodiment, the bonding material can contain up to about 3.0 wt% alkaline earth oxide compound, based on the total weight of the bonding material. In yet other instances, the bonding material may include less alkaline earth, such as on the order of about 2.8% or less, 2.2% or less, about 2.0% or less, or about 1.8% or less. An oxide compound may be contained. Further, according to one embodiment, the bonding material is at least about 0.8 wt%, at least about 1.0 wt%, even at least about 1.4 wt%, etc., based on the total weight of the bonding material, It may contain a content of at least about 0.5% by weight of one or more alkaline earth oxide compounds. It will be appreciated that the amount of alkaline earth oxide compound in the bonding material can be within the range of any of the minimum and maximum percentages described above.

  According to one embodiment, the bonding material can be formed from up to about 3 different alkaline earth oxide compounds. Indeed, the binding material may contain no more than two different alkaline earth oxide compounds. In one particular case, the binding material can be formed from two alkaline earth oxide compounds consisting of calcium oxide and magnesium oxide.

  In one embodiment, the binding material can include an amount of calcium oxide greater than the amount of magnesium oxide. Furthermore, the amount of calcium oxide in the binding material can be greater than the content of any of the other alkaline earth oxide compounds present in the binding material.

  The binding material can be formed from a combination of an alkali oxide compound and an alkaline earth oxide compound such that the total content is not more than about 20% by weight relative to the total weight of the binding material. In other embodiments, the total content of alkaline oxide compounds and alkaline earth oxide compounds in the binding material is no greater than about 19 wt%, such as no greater than about 18 wt%, or even no greater than about 17 wt%. be able to. However, in certain embodiments, the total content of alkali oxide and alkaline earth oxide compounds present in the binding material is at least about 14%, such as at least about 13%, such as at least about 13%, May be at least about 12% by weight, such as at least about 16% by weight. It will be appreciated that the binding material can have a total content of alkali and alkaline earth oxide compounds within any of the minimum and maximum percentage ranges described above.

According to one embodiment, the binding material can be formed such that the content of alkali oxide compounds present in the binding material is greater than the total content of alkaline earth oxide compounds. In one particular embodiment, the binding material has a ratio (R ₂ O: RO) of the total content (weight percent) of the alkaline oxide compound as compared to the total weight percent of the alkaline earth oxide compound. It can be formed to be in the range of about 5: 1 to about 15: 1. In other embodiments, the ratio of the total weight percent of the alkali oxide compound and the total weight percent of the alkaline earth oxide compound present in the bonding material is within the range of about 7: 1 to about 12: 1, and Can be in the range of about 6: 1 to about 14: 1, such as in the range of about 8: 1 to about 10: 1.

  According to one embodiment, the bonding material can be formed from less than or equal to about 3% by weight phosphorous oxide based on the total weight of the bonding material. In certain other instances, the bonding material is about 2.0 wt% or less, about 1.5 wt% or less, about 1.0 wt% or less, about 0.8 wt% or less, based on the total weight of the bonding material. About 2.5 wt% or less, such as about 0.5 wt% or less, or even about 0.2 wt% or less. Indeed, in certain cases, the binding material can be essentially free of phosphorous oxide. A suitable content of phosphorous oxide can facilitate certain characteristics and grinding performance characteristics as described herein.

According to one embodiment, the bonding material is formed from a composition comprising no more than about 1 wt% of an oxide compound, including oxide compounds such as MnO ₂ , ZrSiO ₂ , CoAl ₂ O ₄ , and MgO. can do. Indeed, in certain embodiments, the binding material can be essentially free of the oxide compounds identified above.

  In addition to the bonding material disposed within the mixture, the process of forming a bonded abrasive article can further include the incorporation of certain types of abrasive particles. According to one embodiment, the abrasive particles can comprise microcrystalline alumina (MCA). Indeed, in some cases, the abrasive particles can consist essentially of microcrystalline alumina.

  The abrasive particles can have an average particle size of about 1050 microns or less. In other embodiments, the average particle size of the abrasive particles is 800 microns or less, about 600 microns or less, about 400 microns or less, about 250 microns or less, about 225 microns or less, about 200 microns or less, about 175 microns or less, about 150. It can be made smaller, such as less than a micron, or even about 100 microns or less. Further, the average particle size of the abrasive particles is at least about 5 microns, at least about 10 microns, at least about 20 microns, at least about 30 microns, even at least about 50 microns, at least about 60 microns, at least about 70 microns, or even at least It can be at least about 1 micron, such as about 80 microns. It will be appreciated that the average particle size of the abrasive particles can be within the range of any of the minimum and maximum values described above.

  With further reference to abrasive particles that utilize microcrystalline alumina, it will be appreciated that microcrystalline alumina can be formed of abrasive grains having an average abrasive grain size of submicron size. In fact, the average abrasive grain size of microcrystalline alumina is about 0.5 microns or less, about 0.2 microns or less, about 0.1 microns or less, about 0.08 microns or less, about 0.05 microns or less, Can be about 1 micron or less, such as about 0.02 micron or less.

  In addition, the formation of the mixture comprising abrasive particles and binder further includes the addition of other ingredients such as fillers, pore formers, and materials suitable for forming the final bonded abrasive article. Can do. Some suitable examples of pore-forming materials include: hollow alumina, bubble mullite, hollow glass sphere, hollow ceramic sphere, or hollow sphere including hollow polymer sphere, polymer or plastic material, organic compound, glass, ceramic, or polymer Fiber-like materials including, but not limited to, strands and / or fibers. Other suitable pore forming materials include naphthalene, PDB, shell, wood and the like. In yet another embodiment, the filler can include one or more inorganic materials including, for example, oxides, and in particular includes a crystalline or amorphous phase of zirconia, silica, titania, and combinations thereof. May be included.

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

  After suitably forming the green body, the green body can be sintered at a specific temperature to facilitate the formation of an abrasive article having a vitreous phase binder material. In particular, the sintering operation can be performed at a sintering temperature that is less than about 1000 ° C. In certain embodiments, the sintering temperature may be less than about 980 ° C, such as less than about 950 ° C, particularly in the range of about 800 ° C to 950 ° C. It will be appreciated that particularly low firing temperatures can be utilized for the above-described binding components, thus avoiding extremely high temperatures and thus limiting the degradation of the abrasive particles during the formation process.

  According to one particular embodiment, the bonded abrasive body includes a bonding material having a vitreous phase material. In certain cases, the bonding material can be a single phase vitreous material.

  The finally formed bonded abrasive body can have a specific content of bonding material, abrasive particles, porosity. In particular, the body of the bonded abrasive article can have a porosity of at least about 42% by volume relative to the total volume of the bonded abrasive body. In other embodiments, the amount of porosity is at least about 44% by volume, at least about 45% by volume, at least about 46% by volume, at least about 48% by volume, and even at least about at least about the total volume of the bonded abrasive body. More, such as at least about 43% by volume, such as 50% by volume. According to one embodiment, the bonded abrasive body is about 65% or less, about 62% or less, about 60% or less, about 56% or less, about 52% or less, or even about 50% or less, etc. Of about 70% by volume or less. The bonded abrasive body may include a porosity of about 46% to about 50% of the total volume of the bonded abrasive body, such as a porosity of about 46% to about 48% of the total volume of the bonded abrasive body. It will be appreciated that the bonded abrasive body can have a porosity within the range of any of the minimum and maximum percentages described above.

  According to one embodiment, the bonded abrasive body can have at least about 35% by volume abrasive particles relative to the total volume of the bonded abrasive body. In other embodiments, the total content of abrasive particles can be higher, such as at least about 37% by volume, even at least about 39% by volume. According to one particular embodiment, the bonded abrasive body has no more than about 50 volume% abrasive particles, such as no more than about 48 volume%, or even no more than about 46 volume%, relative to the total volume of the bonded abrasive body. Can be formed. It will be appreciated that the content of abrasive particles within the bonded abrasive body can be within the range of any of the minimum and maximum percentages described above.

  In certain cases, the bonded abrasive body is formed to contain a small content (% by volume) of the bonding material as compared to the porosity and the content of abrasive particles. For example, the bonded abrasive body can have up to about 15% by volume bonded material relative to the total volume of the bonded abrasive body. In other cases, the bonded abrasive body can be formed to contain no more than about 14 volume%, no more than about 13 volume%, or even no more than about 12 volume% relative to the total volume of the bonded abrasive body. In one particular case, the bonded abrasive body is at least about 7% by volume, such as at least about 8% by volume, at least about 9% by volume, or even at least about 10% by volume, relative to the total volume of the bonded abrasive body. It can be formed so as to contain a binding material.

  FIG. 1 includes a diagram of the phases present in a particular bonded abrasive article according to one embodiment. FIG. 1 includes volume percent binder, volume percent abrasive particles, and volume percent porosity. Shaded area 101 represents a conventional bonded abrasive article suitable for grinding applications, while shaded area 103 represents the phase content of a bonded abrasive article according to one embodiment herein.

  In particular, the phase content of conventional bonded abrasive articles (ie, shaded region 101) is significantly different from the phase content of the bonded abrasive article of one embodiment. In particular, conventional bonded abrasive articles generally have a maximum porosity in the range of approximately 40 volume% to 51 volume%, an abrasive particle content of approximately 42 volume% to 50 volume%, and approximately 9 to 20 volume%. Having a binder content of Conventional bonded abrasive articles require a bonded application that has sufficient strength to cope with the excessive forces encountered during grinding, and a highly porous bonded abrasive is not able to handle such forces. In general, it has a maximum pore content of 50% by volume or less.

  According to one embodiment, the bonded abrasive article can have a significantly greater porosity than conventional bonded abrasive articles. For example, one bonded abrasive article of one embodiment can have a pore content in the range of about 51 volume% to about 58 volume% relative to the total volume of the bonded abrasive body. Further, as illustrated in FIG. 1, an embodiment of the bonded abrasive article has an abrasive particle content in the range of about 40 volume% to about 42 volume%, and approximately, relative to the total volume of the bonded abrasive article, and It can have a particularly low binder content in the range of 2% to about 9% by volume.

  In particular, the bonded abrasive body of the embodiment of the present specification can have unique characteristics different from those of a conventional bonded abrasive body. In particular, the bonded abrasive articles herein have specific contents of porosity, abrasive particles, and binders while making the bonded abrasive articles suitable for specific applications such as grinding applications. Characteristics can be shown. For example, in one embodiment, the bonded abrasive body can have a specific modulus of failure (MOR) that can correspond to a specific modulus of elasticity (MOE). For example, the bonded abrasive body can have a MOR of at least 45 MPa for a MOE of at least about 40 GPa. In one embodiment, the MOR can be at least about 46 MPa, such as at least about 47 MPa, at least about 48 MPa, at least about 49 MPa, or even at least about 50 MPa for a 40 GPa MOE. Further, the bonded abrasive body may have a MOR of about 70 MPa or less, such as about 65 MPa or less, or about 60 MPa or less, for a 40 GPa MOE. It will be appreciated that the MOR can be within the range of any of the minimum and maximum values described above.

  In another embodiment, for a bonded abrasive body having an MOE of 45 GPa, the MOR can be at least about 45 MPa. Indeed, for certain bonded abrasive bodies having an MOE of 45 GPa, the MOR can be at least about 46 MPa, such as at least about 47 MPa, at least about 48 MPa, at least about 49 MPa, or even at least about 50 MPa. Further, the MOR can be about 70 MPa or less, about 65 MPa or less, or about 60 MPa or less for a 45 GPa MOE. It will be appreciated that the MOR can be within the range of any of the minimum and maximum values described above.

  MOR can be measured using a standard three-point bend test on a sample size of 4 inches x 1 inch x 0.5 inches (about 101.6 mm x about 25.4 mm x about 12.7 mm) In addition to the sample size, the load is applied across a 1 inch × 0.5 inch (about 25.4 mm × about 12.7 mm) plane, generally in accordance with ASTM D790. The failure load can be recorded and calculated back to MOR using standard equations. The MOE can be calculated by measuring the natural frequency of the composite using a Grindonic Sonic instrument or similar device according to standard techniques in the abrasive grinding wheel industry.

  In one embodiment, the bonded abrasive body can have an intensity ratio that is a measure of MOR divided by MOE. In certain instances, the strength ratio (MOR / MOE) of a particular bonded abrasive body can be at least about 0.8. In other instances, the intensity ratio can 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 is about 2.50 or less, about 2.00 or less, about 1.70 or less, about 1.50 or less, about 1.40 or less, or about 1.30 or less, such as about 3.00 or less. It can be. It will be appreciated that the strength ratio of the bonded abrasive body can be within any of the above-described minimum and maximum values.

  According to one embodiment, the bonded abrasive body may be suitable for use in a specific grinding operation. For example, it has been discovered that the bonded abrasive bodies of the embodiments herein are suitable for grinding operations. In fact, the bonded abrasive body can be utilized without damaging the workpiece and provides suitable or improved grinding performance.

  References herein to the grinding ability of bonded abrasives include centerless grinding, cylindrical grinding, crankshaft grinding, various surface grinding operations, bearing and gear grinding operations, creep feed grinding, and various tool chamber grinding processes, etc. It can be related to the grinding operation. Furthermore, suitable workpieces for grinding operations include inorganic materials or organic materials. In certain instances, the workpiece includes a metal, metal alloy, plastic, or natural material. In one embodiment, workpieces include ferrous metals, non-ferrous metals, metal alloys, metal superalloys, and combinations thereof. In another embodiment, the workpiece includes an organic material, including, for example, a polymeric material. In yet other instances, the workpiece can be a natural material including, for example, wood.

  Some versions of the wheel size of these abrasive articles can range from greater than about 4.5 inches (about 11.43 cm) to about 54 inches (about 137.16 cm) in diameter. Typical stock removal may range from about 0.0001 inch (about 0.0025 mm) to about 0.500 inch (about 12.7 mm), depending on the application.

In certain instances, it has been noted that bonded abrasive bodies can grind workpieces with particularly high removal rates. For example, in one embodiment, the bonded abrasive body can perform a grinding operation with a material removal rate of at least about 0.4 inch ³ / min / inch (258 mm ³ / min / mm). In other embodiments, the material removal rate is at least about 0.5 inch ³ / min / inch (322 mm ³ / min / mm), at least about 0.55 inch ³ / min / inch (354 mm ³ / min / mm). And at least about 0.45 inch ³ / min / inch (290 mm ³ / min / mm), such as at least about 0.6 inch 3 / min / inch (387 mm ³ / min / mm). Furthermore, the material removal rate of a certain bonded abrasive is about 1.2 inches ³ / min / inch (774 mm ³ / min / mm) or less, about 1.0 inches ³ / min / inch (645 mm ³ / min / mm). or less, more about 0.9 inch ³ / min / inch, etc. (580 mm ³ / min / mm) or less, may be about 1.5 inches ³ / min / inch (967Mm ³ / min / mm) or less. It will be appreciated that the bonded abrasive body of the present application can grind a workpiece with a material removal rate within either of the minimum and maximum values mentioned above.

  It is noted that during certain grinding operations, the bonded abrasive bodies of the present application can be ground with a specific 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 instances, the bonded abrasive body is at least about 0.0045 inches (0.114 millimeters), at least about 0.005 inches (0.127 millimeters), or even at least about 0.006 inches ( A depth of cut of at least about 0.004 inches (0.102 millimeters) can be achieved, such as 0.152 millimeters). It is recognized that the depth of cut for grinding operations utilizing the bonded abrasive body herein can be about 0.01 inches (0.254 millimeters) or less, or about 0.009 inches (0.229 millimeters) or less. Will be done. It will be appreciated that the depth of cut can be within the range of any of the minimum and maximum values described above.

  In other embodiments, it has been noted that a bonded abrasive body can grind a workpiece with a maximum power not exceeding about 10 Hp (7.5 kW) while the above grinding parameters are utilized. In other embodiments, the maximum power during the grinding operation can be about 9 Hp (6.8 kW) or less, such as about 8 Hp (6.0 kW) or less, or even about 7.5 Hp (5.6 kW) or less.

  According to another embodiment, during the grinding operation, it is noted that the bonded abrasive articles of the embodiments herein have superior corner retention capabilities, especially compared to conventional bonded abrasive articles. . In practice, the bonded abrasive body is about 0.07 inch (about 1.78 mm) with a depth of cut (Zw) of at least about 1.8, which corresponds to 0.00255 inch / second, radians. It can have the following corner retention factors. In particular, as used herein, a depth of cut of 1.0 corresponds to 0.00142 inches (radio), radians, and a depth of cut (Zw) of 1.4 is 0.00198 inch (0.05029 mm) / sec, equivalent to radians. The corner retention factor should be a measure of the change in radius in inches after grinding a 4330V workpiece, which is a NiCrMoV hardened tempered high strength steel alloy, at a specific depth of cut. Will be recognized. In certain other embodiments, the bonded abrasive article has a depth of cut of at least about 1.80, such as no more than about 0.05 inches, no more than about 0.04 inches, etc. A corner retention factor that is less than or equal to about 0.06 inches (about 1.52 mm).

  In one embodiment, the abrasive article can include a bonded abrasive body having abrasive particles contained within the bonding material. The bonded abrasive body may include an elastic modulus (MOE) of the interface between the abrasive particles and the bonding material 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.

  For example, the elastic modulus MOE of the interface between the abrasive particles and the binding material can be at least about 250 GPa, such as at least about 275 GPa, or even at least about 300 GPa. Alternatively, the elastic modulus MOE at the interface between the abrasive particles and the binding material can be about 350 GPa or less, such as about 325 GPa or less, or even about 320 GPa or less.

  In another embodiment, the abrasive article may include a bonded abrasive body having abrasive particles contained within the bonding material. The bonded abrasive body may include an interface hardness between the abrasive particles and the bonding material of at least about 13 GPa. The bonded abrasive body may be configured to grind a workpiece comprising metal at a speed of less than about 60 m / s. In other examples, the hardness of the interface between the abrasive particles and the binding material can be at least about 14 GPa, or even at least about 15 GPa. Alternatively, the hardness of the interface between the abrasive particles and the binding material may be about 20 GPa or less, such as about 18 GPa or less, or even about 16 GPa or less.

  In yet another example, the bonded abrasive body may include a surface finish of about 125 microinches (about 3.18 mm).

  The bonded abrasive body may function at a feed rate (Z'w) of at least about 1.0 inch (about 25.4 mm) / min. For example, Z′w is about 1.8 inches (about 45.7 mm) / min or less, about 2.0 inches (about 50.8 mm) / min or less, and further 2.2 inches (55.9 mm) / min. Or about 1.4 inches / minute.

In one version, the bonded abrasive body may include a material removal rate of at least about 0.235 in ³ (about 3.851 cm ³ ) / min.

  Embodiments of the abrasive article can include a bonded abrasive body having abrasive particles contained within the bonding material. The bonded abrasive body may include a grinding factor, defined as a change in x-axis radius over a change in feed rate. The grinding factor can be about 0.040 or less. The bonded abrasive body may be configured to grind a workpiece comprising metal at a speed of less than about 60 m / s. The grinding factor can be about 0.035 or less, such as a grinding factor of about 0.030 or less, or even a grinding factor of 0.028 or less.

  In certain embodiments, the bonded abrasive body may include a corner retention factor of about 0.080 inches or less. For example, the corner retention factor of the x-axis is about 0.060 inch (about 1.524 mm) or less, about 0.050 (about 1.270 mm) or less, further 0.042 inch (about 1.067 mm) or less, etc. Of about 0.070 inches (about 1.778 mm).

  The corner retention factor can be expressed as a percent change in the radius of the wheel. For example, for a grindstone having a diameter of 7 inches (ie, a radius of 3.5 inches (about 88.9 mm)), an x-axis corner retention factor of 0.080 inches (about 2.032 mm) is 1- This represents a change in the x-axis radius of the grindstone with a change of (3.5−0.08) /3.5=2.3%. For x-axis corner retention factors of 0.07, 0.06, 0.05, and 0.042, the change in x-axis radius of the wheel is 2%, 1.7%, 1.4%, respectively. And 1.2%. Thus, the bonded abrasive body can have a change in x-axis radius of 3% or less. For example, a bonded abrasive has an x-axis radius change of 2.5% or less, such as about 2% or less, about 1.7% or less, about 1.5% or less, or even about 1.3% or less. Can do.

  Other embodiments of a bonded abrasive body may include a grinding factor, defined as a change in y-axis radius over a change in feed rate. The grinding factor can be about 0.018 or less. Examples of other grinding factors can be about 0.016 or less, such as a grinding factor of about 0.014 or less, a grinding factor of about 0.012 or less, or even a grinding factor of about 0.010 or less.

  In certain embodiments, the bonded abrasive body is about 0.030 inches or less, about 0.025 inches or less, or even about 0.024 inches (about 0.610 mm). It may include a y-axis corner retention factor of about 0.033 inches (about 0.838 mm), such as:

  The corner retention factor can be expressed as a percent change in the radius of the wheel. For example, for a grindstone having a diameter of 7 inches (ie, a radius of 3.5 inches (about 88.9 mm)), a 0.033 inch (about 0.838 mm) y-axis corner retention factor is 1− This represents a change in the y-axis radius of the grindstone with a change of (3.5−0.033) /3.5=0.94%. For y-axis corner retention factors of 0.03, 0.025, and 0.024, the change in the x-axis radius of the grindstone is 0.86%, 0.71%, and 0.69%, respectively.

  Thus, the bonded abrasive body can have a change in y-axis radius of about 1% or less. For example, the bonded abrasive body may have a change in x-axis radius of about 0.9% or less, such as about 0.8% or less, or even about 0.7% or less.

  Other versions of the abrasive article are at least about 3% more than conventional outer diameter abrasive grinding wheels, such as at least about 4%, at least about 5%, or even at least about 6%, than conventional outer diameter abrasive grinding wheels. May include a body that requires less dressing.

  In another example, the body may require a cycle time of at least about 5% less than a conventional outer diameter abrasive grinding wheel. For example, the body may require at least about 10% less cycle time, such as at least about 15% and even at least about 18% less cycle time than conventional outer diameter abrasive grinding wheels.

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

  The abrasive article may be from about 18 inches (about 457.2 mm) to about 30 inches (about 762.0 mm), from about 10 inches (about 254.0 mm) to about 36 inches (about 914.4 mm), or even about 5 inches ( Having a body including a grindstone having an outer diameter in the range of about 24 inches (about 609.6 mm) to about 30 inches (about 762.0 mm), such as about 127.0 mm (about 127.0 mm) to about 54 inches (about 1371.6 mm); Can do.

  Other embodiments of the abrasive article can include a bonding material comprising a single phase vitreous material. Some versions of the bonded abrasive body may include a porosity of at least about 42% by volume of the total volume of the bonded abrasive body, such as a porosity of about 70% or less by volume.

  The bonded abrasive body may comprise at least about 35% by volume abrasive particles of the total volume of the bonded abrasive body. In another example, the bonded abrasive body may include less than about 15% by volume of bonded material of the total volume of the bonded abrasive body.

An example of a binding material may be formed from up to about 20 wt% boron oxide (B ₂ O ₃ ) based on the total weight of the binding material. In another version, the bonding material may comprise a ratio of weight percent silicon oxide (SiO ₂ ) to weight percent aluminum oxide (Al ₂ O ₃ ) (SiO ₂ : Al ₂ O ₃ ) of about 3.2 or less. . The binding material may be formed from up to about 3.0 wt% phosphorous oxide (P ₂ O ₅ ). Alternatively, the binding material can be essentially free of phosphorus oxide (P ₂ O ₅ ).

Other embodiments of the binding material may be formed from an alkaline earth oxide compound (RO). For example, the total amount of alkaline earth oxide compound (RO) present in the binding material can be about 3.0% or less. The binding material may be formed from about three different alkaline earth oxide compounds (RO) selected from the group of calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), strontium oxide (SrO). . The binding material is also selected from the group of compounds consisting of lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), potassium oxide (K ₂ O), and cesium oxide (Cs ₂ O), and combinations thereof. Alkali oxide compounds (R ₂ O) may also be included. The binding material may be formed from a total amount of alkali oxide compound (R ₂ O) of up to about 20% by weight. Alternatively, the binding material may include up to about 3 alkali oxide compounds (R ₂ O). In another example, the content (% by weight) of any alkali oxide compound present in the bonding material may be less than or equal to half of the total content (% by weight) of alkali oxide.

In yet other embodiments, the bonding material is formed from about 55 wt% or less of silicon oxide (SiO ₂ ). The binding material may be formed from at least about 12% by weight aluminum oxide (Al ₂ O ₃ ). The binding material may also be formed from at least one alkaline oxide compound (R ₂ O) and at least one alkaline earth oxide compound (RO), the total content of the alkaline oxide compound and the alkaline earth oxide compound The amount is about 20% by weight or less.

Some examples of binders can be formed from boron oxide (B ₂ O ₃ ) and silicon oxide (SiO ₂ ), and the total content of boron oxide and silicon oxide can be up to about 70% by weight. The content of silicon oxide (SiO ₂ ) can be greater than the content of boron oxide.

In certain versions, the binder may be formed from a composition comprising no more than about 1% by weight oxide compound selected from the group consisting of MnO ₂ , ZrSiO ₂ , CoAl ₂ O ₄ , and MgO. Binding agent _can be formed from _{MnO 2, ZrSiO 2, CoAl 2} O 4, and does not include an oxide compound selected from the group consisting of MgO essentially composition. In addition, the bonded abrasive body can be sintered at a temperature of about 1000 ° C. or less.

Embodiments of the bonding material have a ratio of weight percent silicon oxide (SiO ₂ ) to weight percent aluminum oxide (Al ₂ O ₃ ) of about 2.4 to about 3.5 (SiO ₂ : Al ₂ O ₃ ). May be included. The binding material can include trace amounts (<1%) of Fe ₂ O ₃ , TiO ₂ , and Mg, respectively, and combinations thereof. The binder material may comprise a ratio of about 32 to about 52 weight percent silicon oxide (SiO ₂ ) to weight percent CaO (SiO ₂ : CaO). The bonding material may also include a ratio of about 9.6 to about 26 weight percent silicon oxide (SiO ₂ ) to weight percent Li ₂ O (SiO ₂ : Li ₂ O). In another example, the bonding material may include a ratio of about 4.8 to about 10.4 weight percent silicon oxide (SiO ₂ ) to weight percent Na ₂ O (SiO ₂ : Na ₂ O). The binder material may include a ratio of about 9.6 to about 26 weight percent silicon oxide (SiO ₂ ) and weight percent K ₂ O (SiO ₂ : K ₂ O). The binder material may also include a ratio of about 2.8 to about 5.2 weight percent silicon oxide (SiO ₂ ) to weight percent B ₂ O ₃ (SiO ₂ : B ₂ O ₃ ).

Embodiments of the binding material can include a ratio of about 10 to about 20 weight percent aluminum oxide (Al ₂ O ₃ ) to weight percent CaO (Al ₂ O ₃ : CaO). The binding material may comprise a ratio of about 3 to about 10 weight percent aluminum oxide (Al ₂ O ₃ ) and weight percent Li ₂ O (Al ₂ O ₃ : Li ₂ O). The bonding material may also include a ratio of about 1.5 to about 4 weight percent aluminum oxide (Al ₂ O ₃ ) to weight percent Na ₂ O (Al ₂ O ₃ : Na ₂ O). Examples of binding materials may include a ratio of about 3 to about 10 weight percent aluminum oxide (Al ₂ O ₃ ) and weight percent K ₂ O (Al ₂ O ₃ : K ₂ O). The binder material may also include a ratio of about 0.9 to about 2 weight percent aluminum oxide (Al ₂ O ₃ ) to weight percent B ₂ O ₃ (Al ₂ O ₃ : B ₂ O ₃ ).

In another example, the bonding material may include a weight percent CaO to weight percent Li ₂ O ratio (CaO: Li ₂ O) of about 0.2 to about 0.75. The bonding material may include a weight percent CaO to weight percent Na ₂ O ratio of about 0.1 to about 0.3 (CaO: Na ₂ O. The bonding material may also include about 0.2 to about 0.75. The weight percent CaO to weight percent K ₂ O ratio (CaO: K ₂ O) may include: In addition, the binder material may comprise about 0.16 to about 0.15 weight percent CaO and weight percent B ₂ O. ₃ (CaO: B ₂ O ₃ ).

Other embodiments of the binding material can include a weight percent Li ₂ O to weight percent Na ₂ O ratio (Li ₂ O: Na ₂ O) of about 0.2 to about 1. The binding material can include a ratio of weight percent Li ₂ O to weight percent K ₂ O of about 0.4 to about 2.5 (Li ₂ O: K ₂ O). The binder material can also include a ratio of about 0.12 to about 0.5 weight percent Li ₂ O and weight percent B ₂ O ₃ (Li ₂ O: B ₂ O ₃ ).

Particular embodiments of the binding material may include a ratio of about 1 to about 5 weight percent Na ₂ O to weight percent K ₂ O (Na ₂ O: K ₂ O). The bonding material may also include a ratio of weight percent Na ₂ O to weight percent B ₂ O _{3 of} about 0.3 to about 1 (Na ₂ O: B ₂ O ₃ ). In addition, the bonding material can include a ratio of weight percent K ₂ O to weight percent B ₂ O _{3 of} about 0.12 to about 0.5 (K ₂ O: B ₂ O ₃ ).

Another example of an abrasive article is formed from about 20 wt% or less boron oxide (B ₂ O ₃ ) and about 3.0 wt% or less phosphorous oxide (P ₂ O ₅ ), with about 3.2 wt% Percent abrasive) having a ratio of weight percent of silica (SiO ₂ ) to weight percent alumina (Al ₂ O ₃ ) of less than or equal to about 42 volumes of the total volume of the bonded abrasive body. % Porosity. The bonded abrasive body may be capable of grinding a workpiece comprising metal at a speed of less than about 60 m / s.

  Embodiments of a method for grinding an abrasive article include forming a bonded abrasive body having abrasive particles contained within the bonding material, such that the bonded abrasive body comprises at least about 225 GPa of abrasive particles and the bonding material. Includes the elastic modulus (MOE) of the interface. The method can include grinding 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 bonding material, so that the bonded abrasive body binds at least about 13 GPa of abrasive particles. Includes the hardness of the interface with the material. The method can include grinding 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 for grinding an abrasive article includes forming a bonded abrasive body having abrasive particles contained within the bonding material, so that the bonded abrasive body has an x-axis radius over a change in feed rate. The grinding factor, which is defined as the change in, is about 0.040 or less for a feed rate (Z′w) of at least about 1.0 inch (about 25.4 mm) / min. The method can include grinding 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 also includes forming a bonded abrasive body having abrasive particles contained within the bonding material, and thus the bonded abrasive body is defined as a change in y-axis radius over a change in feed rate. The grinding factor is about 0.018 or less for a feed rate (Z′w) of at least about 1.0 inch (about 25.4 mm) / min. The method can include grinding 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 is formed from about 20 wt% or less boron oxide (B ₂ O ₃ ) and about 3.0 wt% or less phosphorous oxide (P ₂ O ₅ ); Forming a bonded abrasive body having a ratio of weight percent silica (SiO ₂ ) and weight percent alumina (Al ₂ O ₃ ) of 2 (weight percent) or less, wherein the bonded abrasive body is bonded abrasive It has a porosity of at least about 42% by volume of the total body volume. The method can include grinding a workpiece comprising metal with a bonded abrasive body at a speed of less than about 60 m / s.

Example Example 1
The life or performance of a wheel in an external grinding application can depend on the number of times it can be sustained, or the number of parts that can be ground before it loses its shape or corner retention capability, and also affects the quality of the parts. Will give. Wheel life may also be related to the dressing frequency required to create a new surface for subsequent grinding operations. The shape retention ability or corner retention ability of a grindstone can also be related to the ability of a binder to retain abrasive grains and maintain their goodness for effective grinding operations. In this example, an abrasive wheel having 38A fused alumina abrasive particles with different binders was tested. The test apparatus was an MTS Nanoindenter XP using a Berkovich type indenter tip. For each sample, the indenter push is along a double line (see FIG. 2) that extends from the abrasive particle across the particle boundary to the binder region and then into the next abrasive particle. And went in 20 places. The spacing between the indenters in the rows was 10 microns and the rows themselves were separated by a distance of 10 microns. The indenter push was advanced to a depth of 1 micron.

  Figures 3 and 4 show the modulus of elasticity (MOE) and hardness for three different binders, respectively. Diagrams 1301, 1302, and 1303 represent the abrasive, binder, and abrasive-binder interface MOEs of samples of bonded abrasive articles formed in accordance with embodiments herein, respectively. This sample had a binder content range of approximately 7% to approximately 12% by volume of the total volume of the bonded abrasive body. In addition, this sample had a porosity ranging from approximately 46% to approximately 50% by volume of the total volume of the bonded abrasive body.

  In FIG. 3, the first conventional sample CS1 produced MOE values 1305, 1306, and 1307 for the abrasive, binder, and abrasive-binder interface, respectively. Sample CS1 is a bonded abrasive article that is commercially available as a VS product from Saint Gobain Corporation. A second conventional sample CS2 is a bonded abrasive article that is commercially available as a VH product from Saint Gobain Corporation. Sample CS2 yielded MOE values 1310, 1311, and 1312 for the abrasive, bond, and abrasive-binder interfaces, respectively.

  As shown in FIG. 3, the interface MOE 1303 of the embodiment was significantly superior to the interfaces MOE 1307 and 1312 of the conventional samples CS1 and CS2, respectively. Such results show a significant improvement in the MOE of the abrasive-binder interface of bonded abrasive articles formed according to embodiments herein, over prior art bonded bonded articles of the state of the art.

  In FIG. 4, diagrams 1401, 1402, and 1403 represent the hardness of the abrasive, binder, and abrasive-binder interface of a sample of the bonded abrasive article formed according to the embodiment of FIG. 3, respectively. The first conventional sample CS1 produced hardness values 1405, 1406, and 1407 for the abrasive, binder, and abrasive-binder interface, respectively. Sample CS1 is the same as disclosed above for FIG. Similarly, the second conventional sample CS2 yielded hardness values 1410, 1411, and 1412 for the abrasive, binder, and abrasive-binder interface, respectively. Sample CS2 is the same as disclosed above for FIG.

  As shown in FIG. 4, the interface hardness 1403 of the embodiment was considerably superior to the interface hardness 1407 and 1412 of the conventional samples CS1 and CS2, respectively. Such results show a significant improvement in the hardness of the abrasive-binder interface of bonded abrasive articles formed according to embodiments herein, over prior art bonded bonded articles of the state of the art.

  Thus, the new binder has a higher modulus and hardness. This is particularly noticeable for weaker parts (binders and interfaces) in the grinding wheel. An increase in modulus and interface hardness can help strengthen the interface and also indicate that the interface has better connectivity with the abrasive. These designs are useful for improving the life of the grinding wheel under severe grinding conditions.

Example 2
Four samples of 7 inch wheels were prepared for this corner holding application and testing. The four samples included three different conventional binders and one binder according to one embodiment herein. All four samples contained 38A molten alundum abrasive and each had a binder content of about 7% to about 12% by volume and about 46% to about 50% of the total volume of the bonded abrasive body. % Porosity was included. Conventional samples used the same VS and VH binders used in Example 1. Table 1 contains further details regarding the test conditions used in Example 2.

Four samples were tested on a Bryant grinder in a corner holding configuration. The grinding wheel speed was 50.36 m / sec. The test material was 4330 V steel (Rc = 28-32) with an outer diameter of 3.745 inches (about 95.123 mm). The speed of the test material was 1.15 m / sec. The grinding mode was external plunge with a grinding width of 0.100 inch (about 2.54 mm). Each grindstone was dressed with the aid of a reverse-plated diamond roll. The infeed rate was adjusted to obtain target material removal rates (Z'w) of 1.0, 1.4, and 1.8 inches ³ (about 29.5 cm ³ ) / min / inch. Each test grindstone was subjected to continuous grinding in the radial direction 5 times without performing dressing at the target feed speed. A surface finish and waviness was obtained from the workpiece material after the last grinding. For each corner radius and radial wear measurement, a Folica blank that records the wheel profile was ground using a test wheel after each grinding. Measurements were obtained from the blank.

  FIG. 6 includes a diagram of surface finish Ra versus feed rate (Z′w) for three conventional bonded abrasive articles 1600, 1601, and 1602, and bonded abrasive article embodiment 1605. The bonded abrasive body embodiment 1605 includes a surface finish of about 85 microinches (about 2.16 μm) or less at a feed speed (Z′w) of 1.4 inches (about 35.6 mm) / min. In contrast, articles 1600, 1601, and 1602 all exhibited a surface finish of at least about 125 microinches (about 3.18 μm) at a feed rate (Z′w) of 1.4 inches per minute.

FIG. 7 includes a diagram of material removal versus feed rate (Z′w) in five grindings of the same three conventional bonded abrasive articles 1700, 1701, and 1702, and embodiment 1705 of the bonded abrasive article. The bonded abrasive body 1705 included a material removal rate of at least about 0.241 in ³ (about 3.949 cm ³ ) / min at a feed rate (Z′w) of 1.8 inches (about 45.7 mm) / min. . In contrast, conventional articles 1700, 1701, and 1702 all have a material removal of about 0.235 in ³ (about 3.851 cm ³ ) / min or less at a feed rate (Z′w) of 1.8 inches / min. Presented speed.

  A schematic of the change in corner wear or radius measurement is shown in FIG. The dimension 1500 represents the original dimension of the sample along the x-axis (ie, the axial width of 0.875 inches), while dimension 1501 represents the sample along the x-axis. Represents dimensions after grinding. Similarly, dimension 1502 represents the original dimension of the sample along the y-axis (ie, 7 inch diameter), while dimension 1503 is after grinding of the sample along the y-axis. Of dimensions.

  FIG. 8 shows the x-axis radius change versus feed rate (Z′w) line showing the corner retention factor of the same three conventional bonded abrasive articles 1800, 1801, and 1802, and bonded abrasive article embodiment 1805. Includes figures. The bonded abrasive article embodiment 1805 has an x-axis corner retention factor of about 0.042 inches at a feed rate (Z'w) of 1.8 inches. Inclusive. In contrast, conventional articles 1800, 1801, and 1802 all retain x-axis corners of at least about 0.080 inches (about 2.032 mm) at a feed rate (Z'w) of 1.8 inches / minute. Presented a factor.

  In addition, the bonded abrasive body 1805 included a grinding factor, defined as the change in x-axis radius over the change in feed rate. The grinding factor is essentially the average slope of the line in FIG. For example, in the case of the main body 1805, the grinding factor has a numerator of 0.042−0.019 = 0.023. The denominator is 1.80-1.00 = 0.80. The grinding factor is 0.023 / 0.80 = about 0.029. In contrast, articles 1800, 1801, and 1802 had a grinding factor of at least about 0.050.

  Similarly, FIG. 9 shows the same three conventional bonded abrasive articles 1900, 1901, and 1902, as well as the angular retention factor of bonded abrasive article embodiment 1905, versus change in y-axis radius versus feed rate (Z′w). ). The body 1905 exhibited a y-axis corner retention factor of about 0.042 inches at a feed rate (Z'w) of 1.8 inches (about 45.7 mm) / min. Articles 1900, 1901, and 1902 had a y-axis corner retention factor of at least about 0.033 inches at a feed rate (Z'w) of 1.8 inches / minute.

  Based on FIG. 9, the grinding factor was also calculated. For example, in the case of the 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 0.008 / 0.80 = about 0.01. In contrast, articles 1900, 1901, and 1902 had a grinding factor of at least about 0.0188.

  Thus, the change in corner radius along the x-axis and y-axis is the least at all removal rates for products with binders according to embodiments herein compared to products with conventional binding systems It shows the amount of corner wear.

Example 3
This example, as well as an embodiment comprising a combination of sol-gel and fused alumina abrasive, was formed by the binder described above for the previous example. This sample was tested with a centerless plunge applied to a finished shape for a conventional product with a sol-gel and a fused alumina abrasive with the conventional binder VH used above for other examples. The grinding wheel had a diameter of 16 inches (about 406.4 mm) and the ground material was mild steel (1014). The aim was to improve productivity by increasing the number of parts per dress. The grinding wheel speed was 57.45 m / sec and the part speed was 1.15 m / sec.

Table 2 contains further details regarding the test conditions used in Example 3.

  FIG. 10 includes a graph of the number of parts per dress for a conventional bonded abrasive article 2000 and a bonded abrasive article embodiment 2005. Article 2005 showed a significant improvement (about 7% improvement) in the number of parts per dress with a good surface finish or shape compared to article 2000.

  Another advantage that has been observed is that the feed rate for a new wheel can be greatly increased, helping to reduce cycle time. Shorter cycle times have better efficiency of the grinding operation. The same sample described with respect to FIG. 10 was tested for cycle time and the results are shown in FIG. FIG. 11 is a graph of cycle time for a conventional bonded abrasive article 2100 and a bonded abrasive article embodiment 2105. Article 2105 showed a significant improvement (approximately 18%) over article 2100.

  The foregoing embodiments are directed to abrasive products, and in particular to bonded abrasive products that show a breakthrough from the state of the art. The bonded abrasive product of the embodiments herein utilizes a combination of features that help improve grinding performance. As described herein, the bonded abrasive bodies of the embodiments herein utilize a specific amount and type of bonding material, a specific amount and type of bonding material, and a specific amount of porosity. . In addition to the discovery that such products can be efficiently formed, such products have improved grinding performance, despite being outside the known field of conventional abrasive products in terms of their grade and structure. I also found that In particular, it has been discovered that the bonded abrasive of this embodiment can be operated at lower speeds during grinding operations, despite having a much higher porosity than conventional grinding wheels. In fact, very surprisingly, the bonded abrasive bodies of the embodiments herein show the ability to operate at a grinding wheel speed of less than about 60 m / s, while compared to state-of-the-art grinding wheels. Also shown is an improved removal rate, improved corner retention, and a suitable surface finish.

  In the foregoing, references to specific embodiments and certain components are exemplary. References to components as being connected or connected are either direct connections between the components, or one or more intervening, as will be appreciated to perform the methods discussed herein. It will be appreciated that any indirect connection through the components is intended to be disclosed. Thus, the subject matter disclosed above is to be regarded as illustrative and not restrictive, and the scope of the appended claims is to be included within the true scope of the present invention, It is intended to encompass all such modifications, improvements, and other embodiments. Accordingly, the scope of the present invention should be determined by the broadest acceptable interpretation of the following claims and their equivalents to the maximum extent permitted by law, as set forth in the foregoing detailed description. Shall not be limited or limited by

  This summary of the disclosure is provided to comply with patent law and it will not be used to interpret or limit the scope or meaning of the claims It is submitted with the understanding. In addition, in the foregoing detailed description, various features can be grouped together in a single embodiment for the purpose of streamlining the present disclosure or described in a single embodiment. This disclosure should not be construed 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 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 a separate definition of the claimed subject matter.

Claims (15)

An abrasive article,
A bonded abrasive body having abrasive particles contained within the binder material, the bonded abrasive body having an elastic modulus (MOE) of the interface between the abrasive particles and the binder material of at least about 225 GPa;
The bonded abrasive body is configured to grind a workpiece comprising metal at a speed of less than about 60 m / s;
Abrasive article.   The abrasive article of claim 1, wherein the bonded abrasive body has a hardness at the interface between abrasive particles and a binding material of at least about 13 GPa.   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 about 35 m / s.   The bonded abrasive body has a porosity of at least about 42% to about 70% by volume of the total volume of the bonded abrasive body, and the bonded abrasive body is at least about 35 volumes of the total volume of the bonded abrasive body. The abrasive article of claim 1 comprising% abrasive particles. The binding material is formed of at least one alkaline oxide compound (R ₂ O) and at least one alkaline earth oxide compound (RO), and contains the total of the alkaline oxide compound and the alkaline earth oxide compound. The abrasive article of claim 1, wherein the amount is about 20 wt% or less. The abrasive article of claim 1, wherein the bonding material has a weight percent silicon oxide (SiO ₂ ) to weight percent Li ₂ O ratio (SiO ₂ : Li ₂ O) of about 9.6 to about 26. . The binder material of claim 1, wherein the binder material has a ratio of weight percent silicon oxide (SiO ₂ ) to weight percent Na ₂ O (SiO ₂ : Na ₂ O) of about 4.8 to about 10.4. Abrasive article. The abrasive article of claim 1, wherein the bonding material has a ratio of weight percent silicon oxide (SiO ₂ ) to weight percent K ₂ O (SiO ₂ : K ₂ O) of about 9.6 to about 26. . The bonding material according to claim 1, wherein the binder material has a ratio of weight percent silicon oxide (SiO ₂ ) to weight percent B ₂ O ₃ (SiO ₂ : B ₂ O ₃ ) of about 2.8 to about 5.2. The abrasive article as described. The abrasive article of claim 1, wherein the binding material has a ratio of weight percent Li ₂ O to weight percent Na ₂ O (Li ₂ O: Na ₂ O) of about 0.2 to about 1. The abrasive article of claim 1, wherein the binding material has a ratio of weight percent Li ₂ O to weight percent K ₂ O (Li ₂ O: K ₂ O) of about 0.4 to about 2.5. . The abrasive article of claim 1, wherein the binding material has a weight percent Na ₂ O to weight percent K ₂ O ratio (Na ₂ O: K ₂ O) of about 1 to about 5.   The bonded abrasive body includes a grinding factor, defined as a change in x-axis radius over a change in feed rate, wherein the grinding factor is at least about 1.0 inch (about 25.4 mm) / minute feed rate (Z The abrasive article of claim 1, wherein the abrasive article is about 0.040 or less for 'w).   The bonded abrasive body includes a grinding factor, defined as a change in y-axis radius over a change in feed rate, wherein the grinding factor is at least about 1.0 inch (about 25.4 mm) / minute feed rate (Z The abrasive article of claim 1, wherein the abrasive article is about 0.018 or less relative to 'w). The binding material is formed from about 20% by weight or less of boron oxide (B ₂ O ₃ ) and about 3.0% by weight or less of phosphorus oxide (P ₂ O ₅ ) and about 3.2% (by weight) or less. Having a ratio of weight percent silica (SiO ₂ ) to weight percent alumina (Al ₂ O ₃ ), wherein the bonded abrasive body has a porosity of at least about 42% by volume of the total volume of the bonded abrasive body; The abrasive article according to claim 1.