Abstract: A heat treatment furnace jig having a box-like frame including a rim part and a bottom part, the bottom part being removable from the rim part, and a removable net of woven strands disposed in the box-like frame and supported from below by the bottom part. The net has a triaxial weave of strands, each strand having a bundle of carbon fibers that are aligned without twisting, wherein, among the woven strands, strands of at least one direction are held by two strands in another direction, and the net is impregnated with a matrix material.

Abstract: The present invention improves the strength of the bottom (net) of the jig and makes it more difficult and unlikely for deviation of the mesh to occur. A workpiece is loaded on the net (2) of the heat treat furnace jig (hereinafter, heat treatment furnace jig). In the net (2), a first strand (10), a second strand (20) and a third strand (30) are in contact at a contact point (X1). Near the contact point (X1), the second strand (20) overlaps the first strand (10) from above and the third strand (30) overlaps the first strand (10) from below. As a result, the first strand (10) is held between the second strand (20) and the third strand (30) in the up/down directions.

Abstract: The present invention improves the strength of the bottom (net) of the jig and makes it more difficult and unlikely for deviation of the mesh to occur. A workpiece is loaded on the net (2) of the heat treat furnace jig (hereinafter, heat treatment furnace jig). In the net (2), a first strand (10), a second strand (20) and a third strand (30) are in contact at a contact point (X1). Near the contact point (X1), the second strand (20) overlaps the first strand (10) from above and the third strand (30) overlaps the first strand (10) from below. As a result, the first strand (10) is held between the second strand (20) and the third strand (30) in the up/down directions.

Abstract: A purpose is to provide a tray for oil quenching heat treatment furnaces that can inhibit oil infiltration to reduce adverse effects on the quality of the workpiece and also can make lightweight design of the tray possible. Provided is a tray including a carbon material and being capable of placing a workpiece thereon for oil quenching of the workpiece, characterized in that the cumulative pore volume of pores with a pore radius of greater than or equal to 1 ?m is less than or equal to 40 mm3/g in the carbon material. The carbon material is desirably such that a C/C composite is impregnated with a thermosetting resin and burned.

Abstract: There is obtained a carbon material for lithium-ion secondary battery negative electrode, a low-crystalline carbon impregnated carbon material for lithium-ion secondary battery negative electrode, a negative electrode plate, and a lithium-ion secondary battery, each of which realizes a first charge/discharge cycle with less gas generation and provides a rapid charge/discharge. The carbon material is obtained by: blending and kneading a carbonaceous aggregate with a binder to form a composition; press molding the composition into an article; carbonizing the press molded article; graphitizing the article to obtain an artificial graphite block; milling the block; and carrying out particle size control. The carbon material has characteristics of: (1) R-value=(I1360/I1580)?0.2, where R-value is defined by the ratio of D band to G band in Raman spectrum using Nd:YAG laser light of 532 nm wavelength; and (2) d(002)?0.

Abstract: A crucible 1 made of a C/C composite material for use in single crystal pulling, the crucible 1 having a lateral cylindrical portion 11 and a bottom portion 12 integrally formed as multiple layers wound by a filament winding method, in which the first layer 2 as the innermost crucible layer, among the multiple layers, is wound such that carbon fibers form tracks passing the polar point O at the bottom 12, the second layer 3 wound on the outer surface of the first layer 2 is wound along tracks to form a first outer circular bottom 8 that extends outwardly from about a middle part of a raised portion 6 where the carbon fibers of the first layer 2 are localized to the polar point O, and the third layer 4 and the succeeding layers wound on the outer surface of the second layer 3 are wound respectively along tracks to form outer circular bottoms that extend stepwise outwardly from about the middle parts of the outer surfaces of layers situated inside the respective layers, and the top for the raised portion of the

Abstract: A crucible 1 made of a C/C composite material for use in single crystal pulling, the crucible 1 having a lateral cylindrical portion 11 and a bottom portion 12 integrally formed as multiple layers wound by a filament winding method, in which the first layer 2 as the innermost crucible layer, among the multiple layers, is wound such that carbon fibers form tracks passing the polar point O at the bottom 12, the second layer 3 wound on the outer surface of the first layer 2 is wound along tracks to form a first outer circular bottom 8 that extends outwardly from about a middle part of a raised portion 6 where the carbon fibers of the first layer 2 are localized to the polar point O, and the third layer 4 and the succeeding layers wound on the outer surface of the second layer 3 are wound respectively along tracks to form outer circular bottoms that extend stepwise outwardly from about the middle parts of the outer surfaces of layers situated inside the respective layers, and the top for the raised portion of the