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随着发动机性能指标的不断提高,对发动机活塞材料提出了新的更高的要求。在这种情况下,对过共晶Al-Si 合金的实验研究工作日益深入。通过实验研究发现,这种合金作为活塞材料,具有突出的优点:热膨胀系数小。Al-Si 系合金的热膨胀系数随硅含量提高而降低,过共晶Al-Si 合金的热膨胀系数比现用的所有活塞材料都小,用这种合金制造的活塞,容许较小的配缸间隙而不致发生拉缸现象。耐磨性好。这种合金的金相组织的特点使之具有好的耐磨性,可以延长活塞的使用寿命。较高的强度。特别是高温强度较高,可以保证发动机安全运转。
As engine performance continues to improve, new higher requirements are placed on engine piston materials. Under such circumstances, experimental research on hypereutectic Al-Si alloys has been increasingly carried out. Experimental studies have found that this alloy as a piston material, has the outstanding advantages: small thermal expansion coefficient. The thermal expansion coefficient of Al-Si based alloys decreases with increasing silicon content. The hypereutectic Al-Si alloy has a lower coefficient of thermal expansion than all existing piston materials. Pistons made with this alloy allow for smaller cylinder clearance The cylinder will not happen. Good wear resistance. The microstructure of this alloy gives it good wear resistance and extends the life of the piston. Higher intensity. Especially high temperature strength, can ensure the safe operation of the engine.