超重力对梯度Al-Zn-Mg-Cu合金成分和微观组织的影响

Effects of supergravity on composition and microstructure of gradient Al-Zn-Mg-Cu alloy

提出了一种制备梯度Al-Zn-Mg-Cu合金的新方法,通过优化实验的工艺参数,在超重力降温离心的条件下结合定向凝固工艺获得具有梯度的成分含量、显微组织及力学性能。基于合金的析出特性,利用超重力技术和温度梯度区间实现冷却凝固过程中α-Al析出相和共晶T相的高效分离,大部分的α-Al析出相集中在试样顶部,而共晶组织主要分布在试样底部。不同密度的析出相在超重力的作用下分布于样品的不同位置,使得增大重力系数和扩大温度梯度有利于获得梯度范围更大的材料。结果表明,在超重力的条件下,降温离心可以在短时间内获得梯度铝合金,从而为梯度铝合金材料的制备提供了新的工艺手段和思路。

A new method for the preparation of gradient Al-Zn-Mg-Cu alloy was presented in this paper.The composition content,microstructure and mechanical properties in gradient combined with the directional solidification process were obtained by optimizing the experimental parameters under conditions of hypergravity cooling centrifugation.Based on the precipitation characteristics of the alloy,the efficient separation ofα-Al precipitated phase and eutectic T phase during cooling and solidification was realized by supergravity technology and temperature gradient range,in which most of theα-Al precipitated phrase was concentrated at the top of the sample,while the eutectic microstructure was mainly distributed at the bottom of it.Increasing the gravity coefficient and expanding the temperature gradient was beneficial to obtain materials with a larger gradient range,owing to the precipitated phases with different densities distributed at different positions of the sample under the supergravity.The results showed that the gradient aluminum alloys could be obtained in a short time by supergravity cooling centrifugation,thus providing new process means and ideas for the preparation of the gradient aluminum alloy materials.