Abstract: A pitch-based carbon fiber reinforced composite material is improved with regard to its compressive strength and compression strain at failure by combining polyacrylonitrile-based carbon fibers. The pitch-based carbon fibers have a modulus in tension of not less than 400 GPa, a tensile strength of not less than 2000 MPa, a compressive strength as a unidirectionally reinforced composite material of 100 MPa to 800 MPa and a fiber diameter of 4 .mu.m to 15 .mu.m and the polyacrylonitrile-based carbon fibers have a modulus in tension of not less than 200 GPa, a compressive strength and compression strain at failure as a unidirectionally reinforced composite material larger than those of the pitch-based carbon fibers, and a fiber diameter smaller than that of the pitch-based carbon fibers.

Abstract: A rod-type three-dimensional weaving method and apparatus sends weft rods from within a rod magazine between groups of warp rods consisting of a large number of warp rods disposed parallel to one another by means of rod pushers substantially continuously by automatically changing a used-up magazine with another one filled with a new set of weft rod groups. To achieve such continuous weaving, a sensor senses a point where one of the rods in the magazine reaches the preset limit for a magazine change, and a control unit acting on the signal from the sensor removes the used-up magazine and brings another magazine filled with a new set of rod groups into the rod filling position. Or the same control unit stops the rod pushers on one side and starts feeding weft rods from the opposite side by employing the magazine and rod pushers on the opposite side of the group of warp rods, with a significant reduction in the weaving time.

Abstract: A number of rods are disposed along at least three differently oriented axes, the rods being formed by bonding together bundles of fibers with a matrix. Each rod in one group is passed between rods of the other differently oriented groups. The cross-sectional shape of a rod extending in at least one direction is matched to the shape of a clearance which is left between rods extending in other directions to admit the rod inserted therethrough. Put otherwise, a rod extending in at least one direction has a projection to fill such a clearance. Great enough strength to withstand external forces exerted from any direction is imparted to the three-dimensional fabric composite materials either by increasing the area of contact between individual rods or by minimizing the clearances between rods by means of a matrix or the like.

Abstract: A number of rods are disposed along at least three differently oriented axes, the rods being formed by bonding together bundles of fibers with a matrix. Each rod in one group is passed between rods of the other differently oriented groups. The cross-sectional shape of a rod extending in at least one direction is matched to the shape of a clearance which is left between rods extending in other directions to admit the rod inserted therethrough. Put otherwise, a rod extending in at least one direction has a projection to fill such a clearance. Great enough strength to withstand external forces exerted from any direction is imparted to the three-dimensional fabric composite materials either by increasing the area of contact between individual rods or by minimizing the clearances between rods by means of a matrix of the like.

Abstract: A cooling drum for continuous-casting machines, for manufacturing thin metallic strips, and having a surface composing part of a casting mold wall in contact with molten metal, wherein the surface has numerous dimples disposed uniformly thereon and not in contact with each other, and each of the dimples has an opening portion in the form of a circle or an oval with a diameter of from 0.1 to 1.2 mm and a depth of from 5 to 100 .mu.m.