An abrasive article including a substrate having an elongated body, a tacking layer overlying the substrate, and a first type of abrasive particle overlying the tacking layer and defining a first abrasive particle concentration at least about 10 particles per mm of substrate.

An abrasive wire including a steel core and an outer coating including a binder and abrasive particles, the binder being formed by at least one nickel-cobalt alloy layer having a cobalt content of between 20 wt.-% and 85 wt.-% in relation to the weight of the Ni/Co alloy.

Monofilament metal saw wire for a wire saw, wherein the saw wire being provided with a plurality of crimps. The crimps are arranged in at least two different planes, such that, when measured, between measuring rods of a micrometer, over a length comprising crimps in at least two different planes, a circumscribed enveloping D diameter of the saw wire is between 1.05 and 1.50 times a diameter d of the saw wire itself.

A process for manufacturing an abrasive wire formed by abrasive particles held on a central core by a binder comprises depositing abrasive particles on the central core, each particle comprising a magnetic material that has a relative permeability greater than 50 and that represents at least 1% of the volume of the abrasive particle, and depositing binder on the central core to keep the abrasive particles attached to it. The core has south poles and north poles alternating along either its circumference or its length.

Fibers for diamond-impregnated cutting tools and their associated methods for manufacture and use are described. A matrix is formed that contains fibers made from carbon, glass, ceramic, polymer, and the like. The matrix is then sintered to form a cutting portion of a drill bit. The type and concentration of the fibers can be modified to control the tensile strength and the erosion rate of the matrix to optimize the cutting performance of the tools. Additionally, the fibers may be added to the cutting section to weaken the structure and allow higher modulus binders to be used for the cutting tools at a lower cost, allowing the amount of fibers to be tailored to retain the diamonds in the cutting portion for the desired amount. As the cutting portion erodes, the fibers may also increase the lubricity at the face of the cutting portion.

This method of cutting a high-hardness material with a multi-wire saw includes the steps of: (A) providing at least one ingot which includes a body portion 10a with two ends and a low-quality crystal portion 10e that is located at only one of the two ends of the body portion; (B) fixing the at least one ingot onto a fixing base; and (C) slicing the at least one ingot by moving the ingot with respect to a saw wire so that the saw wire does not contact with the low-quality crystal portion 10e of the at least one ingot but does contact with its body portion 10a.

The present invention is a fixed-abrasive-grain wire including a core wire and abrasive grains fixed on a surface of the core wire, wherein an abrasive grain density is 1200 grains/mm.sup.2 or more, where the abrasive grain density is the number of the abrasive grains per unit area on the surface of the core wire, and 2% or less of all distances between centroids of the abrasive grains are equal to or shorter than an average circle equivalent diameter of the whole abrasive grains. There can be provided a fixed-abrasive-grain wire, a wire saw, and a method for slicing a workpiece that can suppress meandering of the fixed-abrasive-grain wire during slicing a workpiece and improve TTV and warp of wafers sliced from the workpiece.

An abrasive article including a substrate having an elongated body, a tacking layer overlying the substrate, a first type of abrasive particle overlying the tacking layer, a second type of abrasive particle different than the first type of abrasive particles overlying the tacking layer, and a bonding layer overlying at least a portion of one of the first type of abrasive particle and the second type of abrasive particle and the tacking layer.

A wire saw which has excellent cutting ability and which is not easily clogged by chips formed by cutting is provided. It has a body 6 having a first metal wire 1 which is made of a cobalt-based alloy, two second metal wires 2a and 2b which are made of a cobalt-based alloy, and three third metal wires 3a-3c which are made of a cobalt-based alloy and are wound on the first metal wire 1. The second metal wires 2a and 2b are helically wound on each of the third metal wires 3a-3c in opposite directions so as to cross each other. Cutting teeth are constituted by projections 8 which are formed by the crossing points of the two second metal wires 2a and 2b.

A method for simultaneously cutting a multiplicity of slices from a cylindrical workpiece, along strictly convex cutting faces, by supplying a suspension of hard substances in a carrier liquid, as cutting medium, to wire portions, while the wire portions, having a longitudinal tension, define a relative motion to the workpiece as a result of wire guide roller rotation with continual alternation between a first direction of rotation and a second direction of rotation, which is opposite to the first direction of rotation, wherein, during the rotation in the first direction, the wire is moved a first length, and during the rotation in the second direction, the wire is moved a second length, and the second length is shorter than the first, and at the cutting operation start a first longitudinal wire tension is greater than a second longitudinal tension at the end.