An apparatus for abrading a surface is provided. The apparatus includes: a framework with a motor housed therein; a chassis housing a drivetrain, the drivetrain including a drive pulley operative connected to the motor, a plurality of tool assembly pulleys, a belt operatively connecting the drive pulley and the plurality of tool assembly pulleys; a plurality of tool assemblies operatively connected to the drive pulley and the plurality of tool assembly pulleys, each tool assembly including: a tool holder, a tool plate comprising a tool segment with an abrading surface, wherein the tool holder and tool plate are detachably connected by a plurality of equidistantly spaced pins, wherein the number of pins is a multiple of three.

Disclosed are an additive raw material composition and an additive for superhard material product, a composite binding agent, a superhard material product, a self-sharpening diamond grinding wheel and a method for manufacturing the same. The raw material composition consisting of components in following mass percentage: Bi.sub.2O.sub.3 25%40%, B.sub.2O.sub.3 25%40%, ZnO 5%25%, SiO.sub.2 2%10%, Al.sub.2O.sub.3 2%10%, Na.sub.2CO.sub.3 1%5%, Li.sub.2CO.sub.3 1%-5%, MgCO.sub.3 0%5%, and CaF.sub.2 1%5%. The composite binding agent is prepared from the additive and a metal composite binding agent. The self-sharpening diamond grinding wheel prepared from the composite binding agent has high self-sharpness, high strength, and fine texture, is uniformly consumed during the grinding process, does not need to be trimmed during the process of being used, and maintains good grinding force all the time, fundamentally solving the problems of long trimming time and high trimming cost of the diamond grinding wheel (FIG. 1).

Disclosed are an additive raw material composition and an additive for superhard material product, a composite binding agent, a superhard material product, a self-sharpening diamond grinding wheel and a method for manufacturing the same. The raw material composition consisting of components in following mass percentage: Bi.sub.2O.sub.3 25%40%, B.sub.2O.sub.3 25%40%, ZnO 5%25%, SiO.sub.2 2%10%, Al.sub.2O.sub.3 2%10%, Na.sub.2CO.sub.3 1%5%, Li.sub.2CO.sub.3 1%-5%, MgCO.sub.3 0%5%, and CaF.sub.2 1%5%. The composite binding agent is prepared from the additive and a metal composite binding agent. The self-sharpening diamond grinding wheel prepared from the composite binding agent has high self-sharpness, high strength, and fine texture, is uniformly consumed during the grinding process, does not need to be trimmed during the process of being used, and maintains good grinding force all the time, fundamentally solving the problems of long trimming time and high trimming cost of the diamond grinding wheel (FIG. 1).

A method produces wafers from a cylindrical ingot of semiconductor material having an axis and an indexing notch in an outer surface of the cylindrical ingot and parallel to the axis. The method includes, in the order specified: (a) simultaneous removal of a multiplicity of sliced wafers from the cylindrical ingot by multi-wire slicing in the presence of a cutting agent; (b) etching of the sliced wafers with an alkaline etchant in an etching bath at a temperature of 20? C. to 50? C. and for a residence time, such that the material removed from each of the sliced wafers is less than 5/1000 of an initial wafer thickness; and (c) grinding of the etched wafers by simultaneous double-disk grinding using an annular abrasive covering.

A method produces wafers from a cylindrical ingot of semiconductor material having an axis and an indexing notch in an outer surface of the cylindrical ingot and parallel to the axis. The method includes, in the order specified: (a) simultaneous removal of a multiplicity of sliced wafers from the cylindrical ingot by multi-wire slicing in the presence of a cutting agent; (b) etching of the sliced wafers with an alkaline etchant in an etching bath at a temperature of 20? C. to 50? C. and for a residence time, such that the material removed from each of the sliced wafers is less than 5/1000 of an initial wafer thickness; and (c) grinding of the etched wafers by simultaneous double-disk grinding using an annular abrasive covering.

A fixed abrasive article having a body including abrasive particles contained within a bond material, the abrasive particles including shaped abrasive particles or elongated abrasive particles having an aspect ratio of length:width of at least 1.1:1, each of the shaped abrasive particles or elongated abrasive particles having a predetermined position or a predetermined three-axis orientation.

An abrasive segment can include an inner segment portion, an outer segment portion, and a central segment portion connected thereto. The inner segment portion can include an inner circumferential wall and an outer circumferential wall. Leading and trailing radial sidewalls can extend between the inner circumferential wall and the outer circumferential wall opposite each other. The outer segment portion can include an inner circumferential wall and an outer circumferential wall. Leading and trailing radial sidewalls can extend between the inner circumferential wall and the outer circumferential wall opposite each other. The central segment portion can include a leading radial sidewall and a trailing radial sidewall. The leading radial sidewall of the central segment portion can establish an acute angle, , with respect to the outer circumferential wall of the inner segment portion and an obtuse angle, , with respect the inner circumferential wall of the outer segment portion.

A grinding wheel which includes a plurality of vitrified bonded grindstone chips arranged on an outer periphery of an annular base metal thereof, and is configured to grind a workpiece with use of the grindstone chips while rotating the annular base metal, wherein each of the vitrified bonded grindstone chips is configured in such a manner that, in a rectangular parallelepiped including a rectangular grinding surface which is placed on an opposite side of the annular base metal and grinds the workpiece and four side surfaces adjacent to grinding surface, four ridge portions each of which is provided between the side surfaces are C-chamfered, each long side of the grinding surface is arranged along the outer periphery of the annular base metal, and each of the four ridge portions is C-chamfered in a range which is or more of a length of each short side of the grinding surface.

A grinding wheel which includes a plurality of vitrified bonded grindstone chips arranged on an outer periphery of an annular base metal thereof, and is configured to grind a workpiece with use of the grindstone chips while rotating the annular base metal, wherein each of the vitrified bonded grindstone chips is configured in such a manner that, in a rectangular parallelepiped including a rectangular grinding surface which is placed on an opposite side of the annular base metal and grinds the workpiece and four side surfaces adjacent to grinding surface, four ridge portions each of which is provided between the side surfaces are C-chamfered, each long side of the grinding surface is arranged along the outer periphery of the annular base metal, and each of the four ridge portions is C-chamfered in a range which is or more of a length of each short side of the grinding surface.

An annular grindstone includes a grindstone portion including a binding material, and abrasive grains which are dispersed into the binding material to be fixed, in which the binding material contains a nickel-iron alloy. Preferably, a contained ratio of iron in the nickel-iron alloy is in a range of 5 wt % or more to less than 60 wt %. More preferably, a contained ratio of iron in the nickel-iron alloy is in a range of 20 wt % or more to 50 wt % or less. Preferably, the annular grindstone includes the grindstone portion only. In addition, the annular grindstone further includes an annular base including a grip portion, in which the grindstone portion is exposed at an outer peripheral edge of the annular base.