Si、Er对Al-Zr合金时效析出行为的影响

Effect of Si and Er on aging precipitation behavior of Al-Zr alloys

本文采用传统铸锭冶金的方法制备不同Si和Er含量的Al-Zr合金,研究Si和Er对Al-Zr合金时效析出行为的影响。结果表明:Si的添加促进了Al-Zr合金的时效硬化响应,Si大大降低第二相Al3Zr的析出温度。Al-0.25Zr-0.30Si合金在325℃等温时效时获得最佳时效强化增量,最高硬度值达到57.1HV,较其固溶态合金增加25.8 HV。Al-Zr合金获得最佳时效硬化增量的Si含量为0.30%(质量分数)。Er的添加进一步促进Al-Zr合金的时效响应,拓宽了Al-Zr合金时效析出温度范围(325~375℃),析出相变得更加细密。Al0.25Zr-0.30Si-0.25Er合金在350℃等温时效时获得最大时效强化增量,最高硬度值达到60.5 HV,这主要是由于Si、Er复合微合金化比单独添加Si更能提高Al-Zr合金沉淀相的数量密度并细化其尺寸。

The effect of Si and Er on the aging behavior of Al-Zr alloy was studied.The results show that the Siaddition promotes the aging strengthening effect of Al-Zr alloy,and greatly reduces the precipitation temperature of Al3Zr precipitates.The Al-0.25Zr-0.30Si alloy obtains the maximum increment of strengthening when isothermal aging at 325℃.The highest hardness is 57.1 HV,which is greater by 25.8 HV than that in the solid solution state.Content of 0.30%Si is optimal to obtain the maximum hardening increment for Al-0.25Zr alloy.The addition of Er further promotes the aging response of Al-Zr alloy,which widens the aging precipitation temperature range(325−375℃)of Al-Zr alloy and the precipitates become finer and denser.Al-0.25Zr-0.30Si0.25Er alloy has the maximum hardening increment as isothermal aging at 350℃and the peak hardness is 60.5 HV.Because co-microalloying with Er and Si can increase the number density and refine the size of precipitates in Al-0.25Zr alloy compared with adding Si alone.