活塞是发动机的关键部件,大多数为铝合金制造,少数用铸铁。由于铝合金比重小,运劫惯性小,可使发动机效率提高,且易制造,放至今φ400mm以下的活塞大都选用它。在薄壁球墨铸铁出现以后,在大于φ400mm的活塞上采用,显现出了很好的耐热性。为了弥朴铝合金活塞的耐热性的不足,就出现丁顶部用铸铁、裙部用铝合金,以螺 Pistons are the key components of the engine, most of the aluminum alloy, a few with cast iron. As a small proportion of aluminum alloy, robbery inertia, can improve the engine efficiency, and easy to manufacture, put the most of the piston below φ400mm choose it. After the emergence of thin-walled ductile iron, the use of piston greater than φ400mm, showing good heat resistance. In order to Pak Plum aluminum piston lack of heat resistance, there Ding Ding with cast iron, skirt with aluminum alloy, snail