新型高铝锌合金挤压铸造的研究

Research on Squeeze Casting of New Type High-Aluminium Zine Base Alloy

挤压铸造可细化Ｚｎ－Ａｌ４３型合金的铸态组织、减轻枝晶偏析、大幅度提高其力学性能，抗拉强度提高４０～８０％（１００～１５０ＭＰａ），延伸率提高至１０％以上，合金的耐磨性亦进一步提高．挤压铸造对合金组织的影响与凝固冷却速度的加快以及合金的平衡凝固温度升高有关，合金塑性、韧性显著改善的首要原因是枝晶间显微缩孔的消除，而合金强度的提高则主要是过饱和固溶体中的脱溶过程导致沉淀硬化与分散硬化的结果．

The refinement of as-cast structure,reduction of dendritic segregationand remarkable improvement of mechnical properties can be achieved by squeeze cast-ing for a Zn-Al43 type alloy.Tensile strength increases by 40～80%(100～150MPa),elongation comes up to 10%,and wear resistance can be further improved.The effect ofsqueeze casting on the structure of the alloy is related to the higher cooling rate duringsolidification and the raised liquidus temperat ure of the alloy,The improvement oftoughness of the alloy is caused primarily by the elimination of interdendritic microshrinkage,while the raised strength is a result of the precipitation hardening accompanying the deposition process in the supersaturated solid solution.