超声处理对Mg-9Al-3Si合金组织及力学性能的影响

研究了超声处理对Mg-9Al-3Si合金凝固组织及力学性能的影响。结果表明,通过控制超声工艺参数可改善Mg-9Al-3Si合金凝固组织,提高其力学性能的目的。在超声功率为0~900W时,随着超声功率增大,合金中的Mg2Si相逐渐细化,其抗拉强度先增后减,转折点为700W。在超声处理时间为0~90s时,随着超声处理时间延长,合金中的Mg2Si相逐渐细化,其抗拉强度先增后减,转折点为60s。分析其断口发现,未经超声处理的合金断裂形式为解理断裂,经过超声处理的合金断口解理台阶尺寸减小,呈准解理断裂特征。

Influence of Ultrasonic Treatment on Solidification Structure and Mechanical Properties of Mg-9Al-3Si Alloy

The effects of ultrasonic power and treatment time on the solidification structure and mechanical properties of Mg-9Al-3Si alloy were investigated.The results reveal that refinement of the structure and improvement of the mechanical properties of the alloy can be achieved by controlling the ultrasonic parameters.In the range of 0~900 W,with the increase of ultrasonic power,the Mg2Si phase in the alloy is gradually refined,and its tensile strength is increased firstly and then decreased,where the turning point is 700 W.In the range of 0~90 s,with the increase of ultrasonic treatment time,the Mg2Si phase in the alloy is gradually refined,and its tensile strength is increased firstly and then decreased,and the turning point is 60 s.The fracture morphology of Mg-9Al-3Si alloy without ultrasonic treatment presents cleavage fracture,while the size of cleavage step of Mg-9Al-3Si alloy is decreased after ultrasonic treatment,characterized by quasi-cleavaye fracture.