Wafers are sliced from a workpiece using a wire saw during slicing operations. The wire saw has a wire web of sawing wire and a setting device. The wire web is stretched in a plane between wire guide rollers that are mounted between fixed and moveable bearings. During each of the slicing operations, the setting device feeds the workpiece through the wire web along a feed direction perpendicular to a workpiece axis and perpendicular to the plane of the wire web. During each of the slicing operations, the movable bearings move oscillatingly axialy. The feeding of the workpiece through the wire web includes a simultaneous displacement of the workpiece along the workpiece axis using the setting element in accordance with a correction profile, which includes an oscillating component that is opposite to the effect which the axial moving of the movable bearings has on the shape of the sliced-off wafers.

A method for preparing a SiC ingot includes: preparing a reactor by disposing a raw material in a crucible body and disposing a SiC seed in a crucible cover, and then wrapping the crucible body with a heat insulating material having a density of 0.14 to 0.28 g/cc; and growing the SiC ingot from the SiC seed by placing the reactor in a reaction chamber and adjusting an inside of the reactor to a crystal growth atmosphere such that the raw material is vapor-transported and deposited to the SiC seed.

The invention relates to a method for separating a plurality of slices from workpieces (4) by means of a wire saw, wherein a wire grating (2) is tensioned in a plane between two wire-guiding rollers (1), wherein each of the two wire-guiding rollers (1) is mounted between a fixed bearing (5) and a floating bearing (6). The method involves delivering the workpiece (4) via the wire grating (2) by controlling the temperature of the workpiece (4) by wetting the workpiece (4) with a cooling medium, while simultaneously axially shifting the floating bearing (6) by controlling the temperature of the fixed bearing (5) with a cooling fluid according to the specification of a first temperature profile, and while simultaneously shifting the workpiece (4) along the workpiece axis by means of a control element (15) according to the specification of a second correction profile.

Slices are cut from workpieces using a wire saw having a wire array tensioned in a plane between two wire guide rollers each supported between fixed and floating bearings and comprising a chamber and a shell enclosing a core and having guide grooves for wires. During a cut-off operation, a workpiece is fed through the wire array perpendicular to a workpiece axis and the wire array plane. The workpiece is fed through the wire array while simultaneously: changing shell lengths by adjusting chamber temperatures in dependence on a depth of cut and a first correction profile; and moving the workpiece along the workpiece axis in accordance with a second correction profile. The correction profiles are opposed to a shape deviation.

A method uses a wire saw to cut slices from a workpiece. The wire saw has an array of saw wire tensioned in a plane between two rollers supported between fixed and floating bearings. During a cut-off operation, the workpiece is fed through the wire array with simultaneous axial movement of the floating bearings by adjusting the temperature of the fixed bearings with a cooling fluid in accordance with the temperature of the cooling fluid being in dependence on a depth of cut and correlating with a first correction profile, which specifies the travel of the floating bearings in dependence on the depth of cut. Also, the workpiece is fed through the wire array while simultaneously moving the workpiece along the workpiece axis in accordance with a second correction profile, specifying the travel of the workpiece. The first and second correction profiles are opposed to a shape deviation.

A tungsten wire that contains tungsten or a tungsten alloy is provided. An average width of surface crystal grains in a direction perpendicular to an axis of the tungsten wire is at most 98 nm. The tungsten wire has a tensile strength of at least 3900 MPa. The tungsten wire has a diameter of at least 100 μm and at most 225 μm.

A method of sampling a multi-layered material and a micro-sampling tool are described. The sampling method includes penetrating a top surface of a material in a component of interest with a micro-cutting tool to a predetermined depth sufficient to include each layer of the multi-layered material and a portion of the base, without cutting through the full depth of the base, undercutting from the depth of penetration through the base to define a micro-sample of the multi-layered material, and removing the micro-sample with each layer of the multi-layered material intact. The micro-sampler includes a cutting tool calibrated to cut to a depth no greater than 2 mm, and in some aspects, no greater than 200 microns into a multi-layered material, the material having a top surface and a metallic or ceramic base and a container for removing and storing a micro-sample cut from the material with each layer of the multi-layered material and a portion of the base intact.

One aspect of the present invention provides a composite sheet which comprises a nitride sintered body having a porous structure and a semi-cured product of a thermosetting resin composition impregnated into the nitride sintered body, the line roughness Rz specified by JIS B 0601:2013 of at least one main surface being 10 μm or less.

Provided is a wire sawing device comprising an ingot temperature controller, the wire sawing device comprising: a chamber; an ingot clamp supporting an ingot inside the chamber; a first roller and a second roller; a wire which is wound around the first roller and the second roller and cuts the ingot into a plurality of wafers by rotating; a temperature measuring unit which is mounted inside the chamber, in which the ingot is cut, and measures the temperature of the ingot; and a heater unit mounted inside the chamber.

A method cuts semiconductor wafers. The method includes: cutting a semiconductor ingot into a workpiece; and sawing the workpiece into slices using a wire grid having a fixed abrasive grain wire, while moving workpiece towards the wire grid. At a first contact of the workpiece with the wire grid, an initial cutting speed is less than 2 mm/min, coolant flow is less than 0.1 l/h and a wire speed is greater than 20 m/s. The workpiece is then guided through the wire grid until a first cutting depth is reached, and then the coolant flow is increased to at least 2000 l/h. The cutting speed is reduced to less than 70% of the initial cutting speed between the first contact of the workpiece with the wire grid up to a cutting depth of half a diameter of the cylinder, and is then increased.