Abstract: There is provided a heat sink having excellent heat dissipation characteristics and mechanical reliability, which is used for motors for electric vehicles, control circuits therefor, internal combustion engines, general power control units, general motors, general semiconductors (CPUs, power modules, etc.), optical semiconductors and various electronic components, etc. The heat sink is configured so that an aluminum alloy layer is formed on at least one side or on both sides of a metallic plate shaped body and fins are formed on the aluminum alloy layer. Because the fins are formed on the aluminum alloy layer provided on the metallic plate shaped body, satisfactory thermal diffusion is effected in the metallic plate shaped body, and the thermal resistance between the metallic plate shaped body and the fin is low, so that the heat radiating effect is high, and the heat sink can be made small. Also, excellent and stable heat dissipation can be achieved for a long period of time.

Abstract: A clamping tool having a clamping head, a cylinder member coupled to an edge portion of the clamping head, a ram member coupled to and movably arranged within the cylinder member, a first die member coupled to the clamping head, and a second die member arranged to face the first die member and movable by the ram member toward and away from the first die member, wherein at least the clamping head is formed of a composite material prepared by dispersing at least one reinforcing material selected from the group consisting of ceramic fibers, ceramic whiskers and ceramic particles into a matrix metal consisting essentially of an aluminum alloy or a magnesium alloy. The clamping head is light, has a high Young's modulus, exhibits a high fatigue resistance, and is free from cracking and scattering of the cracked pieces. The clamping tool permits an operator to operate the clamping tool under a safe environment, and lessens the burden given to the operator, leading to an improved working efficiency.