摘要
在固溶和时效条件相同的情况下 ,选择 3种淬火水温对砂铸 A35 6合金做淬火处理 ,对这 3种淬火态合金的拉伸及疲劳裂纹扩展性能进行了研究 .结果表明 :随淬火介质温度的降低 ,淬火降温速率提高 ,合金的强度增加 ,塑性下降 ;当应力比 R较低时 ,淬火条件对合金疲劳门槛区的裂纹扩展阻力有明显影响 .降低淬火介质温度可以提高合金疲劳裂纹面的粗糙度 ,增加粗糙度诱发的裂纹闭合 ,同时还能降低α( Al)基体中的粗大β′-Mg2 Si相和无沉淀区 。
The tensile performance and fatigue crack growth behavior of sand casting A356 aluminum alloys with three different quench conditions in same solution heat treatment and aging condition are investigated. The results show that the ultimate tensile strength and yield strength of the alloys rise but the total elongation decreases as the temperature of quench medium drops. When stress ratio R is relatively low, quench condition has obviously influence on the near-threshold crack growth behavior of the alloy. Raising quench rate can increase the asperity of fatigue crack plane, therefore enhance asperity-induced closure, and it also can decrease bulky β′-Mg 2Si phase and non\|precipitate zone. So, the fatigue crack growth resistance of the alloy is strengthened.
出处
《郑州大学学报（自然科学版）》
2001年第4期46-49,共4页
Journal of Zhengzhou University (Natural Science)
