河北科技大学学报2017，Vol.38Issue(2)：196-201,6.DOI:10.7535/hbkd.2017yx02015
工艺参数对7075半固态铸-锻组织均匀性的影响
Influence of process parameters on the uniformity of microstructure of semi-solid casting-forging 7075 alloy
摘要
Abstract
Liquid phase segregation frequently occurs in the process of semi-solid die forging,which makes the parts appear "weak point" or "weak region",and usually,the "weak point" or "weak area" is the reason of crack and service condition failure.In order to analyze the influencing factors for the liquid phase segregation of the semi-solid die forging,in this paper,the sample of semi-solid 7075 alloy is prepared by hand stirring method.The casting-forging forming of the sample is made by means of press machine and cup mould to research the influence of alloy temperature,head preheating temperature,hold time and other process parameters on the uniformity of the microstructure.The results show that the semi-solid casting-forging process is feasible within a set of mold.Under the conditions of head temperature of 400 ℃,hold time of 2 s and the forming pressure of 50 MPa,the liquid phase segregation degree of cup sample increases,the uniformity of the microstructure becomes worse with increasing of alloy temperature.The segregation degree is up t0 14.02％ when the alloy temperature is 628 ℃.The liquid phase segregation degree of cup sample decreases and uniformity of the microstructure becomes better along with increasing of head preheating temperature.Under the conditions of alloy temperature of 621 ℃,the forming pressure of 50 MPa,and head preheating temperature of 400 ℃,the liquid phase segregation degree of cup sample decreases,the uniformity of the microstructure becomes better along with increasing of the hold time.The segregation degree is up t0 2.99％ when the hold time is 4 s.The results could provide theoretical reference for the process formulation and experimental research of aluminum alloy semi-solid casting-forging forming.关键词
铸造工艺与设备/半固态铸-锻/保持时间/7075合金/组织均匀性/液相偏析度Key words
foundry technique and equipment/semi-solid casting-forging/hold time/7075 alloy/uniformity of the microstructure/liquid phase segregation degree分类
矿业与冶金引用本文复制引用
谭建波,魏胜辉,刘雪萍..工艺参数对7075半固态铸-锻组织均匀性的影响[J].河北科技大学学报,2017,38(2):196-201,6.基金项目
河北省自然科学基金(E2014208087) （E2014208087）
河北省高等学校科学技术研究项目(ZD2015003) （ZD2015003）
河北省引进留学人员资助项目(C201400515) （C201400515）
