一、前言 活塞在高温(300℃)、高压及高应力状态下工作,在气缸内作往复运动,活塞与气缸间应有良好的气密性,配缸间隙要小。因此,要求活塞材料比重小,重量轻,导热性好、热膨胀系数低,尺寸稳定性及耐磨耐蚀性好,足够高的高温(300℃)强度及弹性模数,所以活塞材料的物理机械性能是影响活塞质量的主要因素。 用作铝活塞的铸造铝合金大体分为四 First, the preamble Pistons work at high temperature (300 ℃), high pressure and high stress, reciprocating motion in the cylinder, piston and cylinder should have a good air tightness, with cylinder clearance to be small. Therefore, the piston material requires a small specific gravity, light weight, good thermal conductivity, low coefficient of thermal expansion, dimensional stability and wear resistance, good high temperature (300 ℃) strength and elastic modulus, so the physical mechanical piston Performance is the main factor affecting the quality of the piston. Cast aluminum used as aluminum piston is roughly divided into four