Methods of making vitreous bond abrasive articles and their precursors using powder bed jetting are disclosed. Vitreous bond abrasive articles prepared by the method include abrasive articles having arcuate or tortuous cooling channels, unitary structured abrasive discs, abrasive segments, shaped abrasive particles, and abrasive wheels.

A processing tool for removing a chamfer of a wafer that is formed on its front surface with a central region and a peripheral surplus region, the chamfer being formed in the peripheral surplus region. The processing tool includes an annular grinding grindstone with an opening into which a spindle is inserted and having first and second side surfaces and a polishing grindstone formed on at least one of the first side surface or the second side surface. The processing tool is formed in such a manner as to satisfy both the following conditions (1) and (2):

[00001]$\begin{array}{cc}H+h>L& \left(1\right)\end{array}$$\begin{array}{cc}L/3>h>L/100& \left(2\right)\end{array}$

where L is a length in a radial direction from a peripheral end of the chamfer to be removed, H is a width of the grinding grindstone, and h is a width of the polishing grindstone.

A processing tool for removing a chamfer of a wafer that is formed on its front surface with a central region and a peripheral surplus region, the chamfer being formed in the peripheral surplus region. The processing tool includes an annular grinding grindstone with an opening into which a spindle is inserted and having first and second side surfaces and a polishing grindstone formed on at least one of the first side surface or the second side surface. The processing tool is formed in such a manner as to satisfy both the following conditions (1) and (2):

[00001]$\begin{array}{cc}H+h>L& \left(1\right)\end{array}$$\begin{array}{cc}L/3>h>L/100& \left(2\right)\end{array}$

where L is a length in a radial direction from a peripheral end of the chamfer to be removed, H is a width of the grinding grindstone, and h is a width of the polishing grindstone.

A grinding worm being a dressable grinding worm, wherein a first section of the grinding worm has a first abrasive grain which is incorporated in a matrix material and wherein a second section of the grinding worm has second abrasive grain which is incorporated in the matrix material. The first abrasive grain and the second abrasive grain differ from one another in terms of grain size and/or grain material. A transition section is formed between the first section and the second section, in which both the first abrasive grin and the second abrasive grain are incorporated in fie matrix material, wherein the first section, the second section and the transition section have the same matrix material and wherein an intermixing of the first abrasive grain and the second abrasive grain is formed at least in sections in the transition section.

A grinding worm being a dressable grinding worm, wherein a first section of the grinding worm has a first abrasive grain which is incorporated in a matrix material and wherein a second section of the grinding worm has second abrasive grain which is incorporated in the matrix material. The first abrasive grain and the second abrasive grain differ from one another in terms of grain size and/or grain material. A transition section is formed between the first section and the second section, in which both the first abrasive grin and the second abrasive grain are incorporated in fie matrix material, wherein the first section, the second section and the transition section have the same matrix material and wherein an intermixing of the first abrasive grain and the second abrasive grain is formed at least in sections in the transition section.

An abrasive tool including a bonded abrasive including a body comprising abrasive particles contained within a three-dimensional matrix of bond material, the bond material including an organic material, the abrasive tool further including a first filler contained within the three-dimensional matrix of bond material including a silicate in a first content and a second filler contained within the three-dimensional matrix of bond material including a sulfate in a second content, and the first content is greater than the second content.

A multi-abrasive tool is constituted by a support on which abrasive elements are present. Such abrasive elements are arranged in a manner so as to form one or more paths along which the successive abrasive elements have grain size sequentially increasing or decreasing by an arbitrary quantity when passing from on element to the next. Such principle gives rise to abrasive tools with different conformation both for polishing machines and for grindstones. For roto-orbital and planetary polishing machines, and optionally orbital, such support is circular and the grain sequence is circumferential, or radial, or in both directions. A first tool is constituted by contiguous (or non-contiguous) circular rings, that are differently abrasive. A second tool comprises differently abrasive elements arranged along the circular peripheral edge. A third tool comprises differently abrasive elements arranged along a spiral path of 360 starting from the edge. A fourth tool comprises two 180 spiral paths with reversed roughness sequences. A fourth tool comprises pairs of differently abrasive small cylinders fixed to a plate on concentric circumferences. A fifth tool is obtained directly on the plate of the polishing machine by means of reliefs and spacers for fixing differently abrasive sectors. For linear polishing machines, the abrasive support is a belt along which differently abrasive rectangular or oblique zones follow each other. For alternative polishing machines, the abrasive support is a plate shaped like the aforesaid belt. For tools to use with grindstones, the multi-abrasive element has a cylindrical rotation symmetry, or conical with rounded tip, or spherical symmetry.

A multi-abrasive tool is constituted by a support on which abrasive elements are present. Such abrasive elements are arranged in a manner so as to form one or more paths along which the successive abrasive elements have grain size sequentially increasing or decreasing by an arbitrary quantity when passing from on element to the next. Such principle gives rise to abrasive tools with different conformation both for polishing machines and for grindstones. For roto-orbital and planetary polishing machines, and optionally orbital, such support is circular and the grain sequence is circumferential, or radial, or in both directions. A first tool is constituted by contiguous (or non-contiguous) circular rings, that are differently abrasive. A second tool comprises differently abrasive elements arranged along the circular peripheral edge. A third tool comprises differently abrasive elements arranged along a spiral path of 360 starting from the edge. A fourth tool comprises two 180 spiral paths with reversed roughness sequences. A fourth tool comprises pairs of differently abrasive small cylinders fixed to a plate on concentric circumferences. A fifth tool is obtained directly on the plate of the polishing machine by means of reliefs and spacers for fixing differently abrasive sectors. For linear polishing machines, the abrasive support is a belt along which differently abrasive rectangular or oblique zones follow each other. For alternative polishing machines, the abrasive support is a plate shaped like the aforesaid belt. For tools to use with grindstones, the multi-abrasive element has a cylindrical rotation symmetry, or conical with rounded tip, or spherical symmetry.

A grinding disc includes an inner layer (20) which is made of grindable material (containing abrasive particles) and an outer layer (20) which covers at least a portion of the surface of the inner layer (50) and which is made of non-grindable material (i.e. not-containing abrasive grain).

A gear-grinding multilayer grindstone includes: a first thread-shaped grindstone and a second thread-shaped grindstone that are fixed to each other, such that the first and second thread-shaped grindstones have a rotational axis that is common to the first and second thread-shaped grindstones; and a thread-shaped groove that is provided in a first outer circumferential surface of the first thread-shaped grindstone and a second outer circumferential surface of the second thread-shaped grindstone. The thread-shaped groove extends continuously over the first outer circumferential surface and the second outer circumferential surface. The second thread-shaped grindstone is constituted by abrasive cloths that are laminated on each other, and has a higher elasticity than the first thread-shaped grindstone.