Abstract: A new substrate manufacturing method of obtaining a SiC epitaxial substrate having excellent flatness and a SiC epitaxial substrate having excellent flatness are provided. In a SiC epitaxial substrate having an epitaxial film obtained by epitaxially growing silicon carbide on a front surface of a silicon carbide substrate, the SiC epitaxial substrate has a first main surface made of the epitaxial film and a second main surface opposite to the first main surface. A maximum value of SBIR on the second main surface based on a 10 mm square site satisfies a condition of 0.1 µm or more and 1.5 µm or less.

Abstract: 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.

Abstract: An identification mark formation method for forming an identification mark on a refractory material single crystal substrate that is made of one selected from the group consisting of sapphire, gallium nitride, aluminum nitride, diamond, boron nitride, zinc oxide, gallium oxide, and titanium dioxide is disclosed. The method includes: (a) scanning a principal surface of the refractory material single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the refractory material single crystal substrate, thereby forming an identification mark in the principal surface of the refractory material single crystal substrate; and (b) scanning an inside of the groove of the refractory material single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: An identification mark formation method for forming an identification mark on a refractory material single crystal substrate that is made of one selected from the group consisting of sapphire, gallium nitride, aluminum nitride, diamond, boron nitride, zinc oxide, gallium oxide, and titanium dioxide is disclosed. The method includes: (a) scanning a principal surface of the refractory material single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the refractory material single crystal substrate, thereby forming an identification mark in the principal surface of the refractory material single crystal substrate; and (b) scanning an inside of the groove of the refractory material single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: An identification mark formation method for forming an identification mark on a refractory material single crystal substrate that is made of one selected from the group consisting of sapphire, gallium nitride, aluminum nitride, diamond, boron nitride, zinc oxide, gallium oxide, and titanium dioxide is disclosed. The method includes: (a) scanning a principal surface of the refractory material single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the refractory material single crystal substrate, thereby forming an identification mark in the principal surface of the refractory material single crystal substrate; and (b) scanning an inside of the groove of the refractory material single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: In a method of cutting a high-hardness material with a multi-wire saw, an ingot of the high-hardness material is sliced into a plurality of wafers by cutting the ingot at multiple points simultaneously with the multi-wire saw. The method comprises repeating a run cycle of reciprocating motion of a wire of the multi-wire saw so that the relationships (1) c1?20, given C1=b/a and (2) 0.35?c2?1.55, given c2=d/a are satisfied, where a is a maximum total contact length defined as a sum of the lengths of the ingot as projected onto multiple cut points when projecting the ingot onto the wire in a direction in which the ingot is going to be cut, b is a continuous travel distance of the wire, and d is a length of the wire newly fed in each said run cycle.

Abstract: A method for forming an identification mark on a silicon carbide single crystal substrate according to the present invention includes: (a) scanning a principal surface of a silicon carbide single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the silicon carbide single crystal substrate, thereby forming an identification mark which is constituted of one or more grooves in the principal surface of the silicon carbide single crystal substrate; and (b) scanning an inside of the groove formed in the principal surface of the silicon carbide single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: 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.

Abstract: A method for forming an identification mark on a silicon carbide single crystal substrate according to the present invention includes: (a) scanning a principal surface of a silicon carbide single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the silicon carbide single crystal substrate, thereby forming an identification mark which is constituted of one or more grooves in the principal surface of the silicon carbide single crystal substrate; and (b) scanning an inside of the groove formed in the principal surface of the silicon carbide single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: A method for forming an identification mark on a silicon carbide single crystal substrate according to the present invention includes: (a) scanning a principal surface of a silicon carbide single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the silicon carbide single crystal substrate, thereby forming an identification mark which is constituted of one or more grooves in the principal surface of the silicon carbide single crystal substrate; and (b) scanning an inside of the groove formed in the principal surface of the silicon carbide single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: An identification mark formation method for forming an identification mark on a refractory material single crystal substrate that is made of one selected from the group consisting of sapphire, gallium nitride, aluminum nitride, diamond, boron nitride, zinc oxide, gallium oxide, and titanium dioxide is disclosed. The method includes: (a) scanning a principal surface of the refractory material single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the refractory material single crystal substrate, thereby forming an identification mark in the principal surface of the refractory material single crystal substrate; and (b) scanning an inside of the groove of the refractory material single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: A method for forming an identification mark on a silicon carbide single crystal substrate according to the present invention includes: (a) scanning a principal surface of a silicon carbide single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the silicon carbide single crystal substrate, thereby forming an identification mark which is constituted of one or more grooves in the principal surface of the silicon carbide single crystal substrate; and (b) scanning an inside of the groove formed in the principal surface of the silicon carbide single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

Abstract: An apparatus for grinding a magnetic member comprises a cutting blade having a cutting edge including heat resistant resin and abrasive grain. A magnetic member including a rare-earth alloy is ground by the cutting blade while grinding fluid primarily made of water is supplied to a grinding region. A magnet separator having a surface magnetic flux density not smaller than 0.25 T magnetically separates sludge from used grinding fluid. Further, the grinding fluid is introduced into a tank, where the sludge contained in the grinding fluid is allowed to coagulate and sediment. The grinding fluid separated from the sludge is used in circulation. The same separation process can be used for separation of sludge containing a rare-earth alloy from waste fluid.

Abstract: A method of cutting a rare-earth alloy with a wire saw, obtained by fixing abrasive grains on a core wire with a resin layer, includes the step of moving the wire saw while a portion of the rare-earth alloy being machined with the wire saw is immersed in a coolant, which is mainly composed of water and has a surface tension of about 25 mN/m to about 60 mN/m at about 25° C., thereby cutting the rare-earth alloy. In the wire saw, an average distance between two of the abrasive grains, which are adjacent to each other in a length direction, is about 150% to less than about 400% of the average grain size of the abrasive grains, an average height of portions of the abrasive grains, protruding from the surface of the resin layer, is about 70% or less of the average grain size of the abrasive grains, and a thickness deviation percentage of the resin layer with respect to the core wire is about 40%.

Abstract: A method of cutting a rare-earth alloy with a wire 20, on which abrasive grains are fixed with a resin layer provided on the outer surface of a core wire, includes the steps of: providing a wire, of which the surface is coated with a lubricant including a glycol, by reeling the wire up in a pair of reel bobbins 40a and 40b; reeling the wire off one of the reel bobbins and letting the wire travel on a plurality of rollers 10a, 10b and 10c; and cutting the rare-earth alloy with the traveling wire while a portion of the rare-earth alloy being cut with the wire is supplied with a first coolant which is mainly composed of water. As a result, the life of a wire can be extended when a rare-earth alloy is cut with a wire saw machine using a coolant which is mainly composed of water.

Abstract: A method of cutting a rare-earth alloy with a wire saw, obtained by fixing abrasive grains on a core wire with a resin layers, includes the step of moving the wire saw while a portion of the rare-earth alloy being machined with the wire saw is immersed in a coolant, which is mainly composed of water and has a surface tension of about 25 mN/m to about 60 mN/m at about 25° C., thereby cutting the rare-earth alloy. In the wire saw, an average distance between two of the abrasive grains, which are adjacent to each other in a length direction, is about 150% to less than about 400% of the average grain size of the abrasive grains, an average height of portions of the abrasive grains, protruding from the surface of the resin layer, is about 70% or less of the average grain size of the abrasive grains, and a thickness deviation percentage of the resin layer with respect to the core wire is about 40%.

Abstract: A work chamfering apparatus includes a work holding portion. The work holding portion includes a work table and a clamper. The work table has an upper surface having two end portions each formed with holding grains projecting out of the upper surface. The two end portions of the upper surface of the work table have a static friction coefficient greater than 0.1, which is greater than that of a center portion. When chamfering, first, the work is held by the work table and a generally U-shaped member of the clamper. At this time, the two end portions of the upper surface of the work table contact a lower surface of the work, whereas lower surfaces of respective end portions of the U-shaped member contact an upper surface of the work. In this state, a rotating center of the work is between the lower surfaces, and the lower surfaces are apart generally equally from the rotating center.

Abstract: A method for cutting a rare earth alloy using a wire with abrasive grains fixed to a core wire, including the step of cutting the rare earth alloy with the wire traveling in a state that a portion of the rare earth alloy to be cut with the wire is immersed in a coolant containing water as the main component, the coolant having a surface tension at 25° C. in a range of 25 mN/m to 60 mN/m.

Abstract: A work cutting apparatus comprises a bed. The bed has an upper surface provided with a column including a rail slidably mounted with a slider. The slider has a front surface mounted with a supporting portion supporting two end portions of a rotating shaft. The rotating shaft is mounted with a plurality of cutting blade blocks. Each of the cutting blade blocks includes a plurality of cutting blades and a thicker cutting blade at each end of the cutting blade block. A table provided with a recess having a V-shaped section is disposed on the bed right beneath the cutting blade blocks. A plurality of works are disposed in the recess, each fixed by a fixing member. The cutting blades lowered while rotating, thereby cutting the works. During this operation, coolant is discharged from a plurality of supplying ports of a coolant supplying portion as well as from a supplying port of a coolant supplying path.

Abstract: A method for cutting a rare earth alloy using a wire with abrasive grains fixed to a core wire, including the step of cutting the rare earth alloy with the wire traveling in a state that a portion of the rare earth alloy to be cut with the wire is immersed in a coolant containing water as the main component, the coolant having a surface tension at 25° C. in a range of 25 mN/m to 60 mN/m.