Sr和超声对富铁A356合金凝固组织及力学性能的影响
Effects of Sr and Ultrasound on Solidified Structure and Mechanical Properties of Iron-rich A356 Alloy
陈志堂 1周全 1彭家辉 1潘俊霖1
作者信息
- 1. 南昌航空大学航空制造工程学院,南昌 330063
- 折叠
摘要
利用OM、SEM、EDS、XRD、布氏硬度计及拉伸试验机等手段,研究了Sr和超声处理对富铁A356合金凝固组织及力学性能的影响.结果表明,Sr和超声处理均可以有效细化合金初生晶粒、共晶Si相和富Fe相并提高其力学性能;与未处理合金相比,复合处理合金的针状富Fe相长度减小了66%,其布氏硬度、抗拉强度和伸长率分别提高了23.1%、43.5%和120.3%;复合处理条件下,在0～900 W范围内,随着超声功率提高,合金的初生晶粒和共晶Si相逐渐细化,针状富Fe相尺寸逐渐减小;在0～90 s内,随着超声处理时间增加,合金的初生晶粒和共晶Si相先细化后粗化,针状富Fe相尺寸先减小后增大,转折点均为60 s.富铁A356合金的力学性能与其凝固组织基本对应,合金的初生晶粒、共晶Si相及富Fe相越细小,其拉伸性能和硬度越高.
Abstract
Effects of Sr and ultrasound on solidified structure and mechanical properties of iron-rich A356 alloy were investigated by OM,SEM,EDS,XRD,Brinell hardness tester and tensile tester.The results indicate that Sr and ultrasonic treatment can effectively refine primary grain,eutectic Si phase and iron-rich phase and improve mechanical properties of the alloy.Compared with that of untreated alloy,the length of needle-like iron-rich phase of the compos-ite treated alloy is decreased by 66%,and Brinell hardness,tensile strength,and elongation are increased by 23.1%,43.5%,and 120.3%,respectively.Under the compound treatment condition,in the range of 0～900 W,grains and eutectic Si phase in the alloy are refined gradually with the increase of processing power,and size of the iron-rich phase is reduced gradually.In the range of 0～90 s,with the ultrasound progressing,grains and eutectic Si phase in the alloy are refined at first and then coarsened and size of the iron-rich phase is decreased at first and then increased with the turning points of 60 s.The mechanical properties of iron-rich A356 alloy are directly retated with solidified structure.With decreasing in the grain size,eutectic Si phase and iron-rich phase of the alloy,the tensile properties and hardness are improved.
关键词
Sr/超声复合处理/富铁A356合金/凝固组织/力学性能Key words
Sr/Ultrasonic Composite Treatment/Iron-rich A356 Alloy/Solidified Structure/Mechanical Properties引用本文复制引用
出版年
2025
NETL
NSTL
万方数据