CAJ | 학술논문

通过显微组织观察、X射线及电子衍射结构分析对挤压态Mg98Zn1.2Y0.8合金的第二相结构及分布,以及Mg基固溶体组织形态进行了研究,并对其100/s ~667/s应变速率下的力学行为及断裂机制进行了分析.结果表明：Mg98Zn1.2Y0.8合金在300℃、挤压比为16的热挤压过程中发生了完全的动态再结晶；挤压态组织为晶粒细小的镁基固溶体、其上弥散分布的化合物H相,以及沿晶界分布的Z相.室温下随着应变速率从100/s提高到667/s,挤压态Mg98Zn1.2Y0.8合金的屈服强度及抗拉强度明显升高,延伸率也从9.2%提高到13%.室温下应变速率为100/s~667/s时挤压态Mg98Zn1.2Y0.8合金的拉伸断裂方式是以韧性断裂为主并伴有脆性断裂的混合断裂.
통과현미조직관찰、X사선급전자연사결구분석대제압태Mg98Zn1.2Y0.8합금적제이상결구급분포,이급Mg기고용체조직형태진행료연구,병대기100/s ~667/s응변속솔하적역학행위급단렬궤제진행료분석.결과표명：Mg98Zn1.2Y0.8합금재300℃、제압비위16적열제압과정중발생료완전적동태재결정；제압태조직위정립세소적미기고용체、기상미산분포적화합물H상,이급연정계분포적Z상.실온하수착응변속솔종100/s제고도667/s,제압태Mg98Zn1.2Y0.8합금적굴복강도급항랍강도명현승고,연신솔야종9.2%제고도13%.실온하응변속솔위100/s~667/s시제압태Mg98Zn1.2Y0.8합금적랍신단렬방식시이인성단렬위주병반유취성단렬적혼합단렬.
The structure of compounds and the microstructure of as-extruded Mg98 Zn1. 2 Y0. 8 alloy were investigated through OM, SEM, TEM and XRD.The dynamic behavior at high strain rate conditions of as-extruded Mg98 Zn1. 2 Y0. 8 alloy was also researched through the tensile test and fracture surface observation.The results show that the complete dynamic recrystallization occurs in the Mg98Zn1.2Y0.8 alloy during extruding process at a temperature of 300 ℃ and a reduction ratio of 1 6:1 .The fine particles of compound H-phase dispersively distribute in the Mg-based solid solution with fine grain size, and the particles of Z-phase mainly distribute along the grain boundaries.At room temperature, the yield strength and the tensile strength rise with the increase of strain rates from 1 00 /s to 667 /s, and the elongation also increases from 9. 2% to 1 3%. Ductile fracture with some proportion of brittleness fracture occurs in the as-extruded Mg98Zn1.2Y0.8 alloy at room temperature and strain rate 1 00 /s -667 /s.