CAJ | 학술논문

在250℃下以Bc路径对Al-10Mg-4Si合金进行4道次和8道次的等通道转角挤压,以求达到改善合金组织和提高合金力学性能的目的.扫描电子显微镜(SEM)和透射电子显微镜(TEM)对挤压前后的微观组织分析表明:铸态合金基体晶粒比较粗大,第二相Mg_2Si以粗大的汉字状或骨骼状分布于基体晶界处;经ECAP挤压后,基体晶粒得到细化,原粗大的汉字状Mg_2Si被碎化为短棒状或多边形状颗粒,并呈一定的弥散分布.室温拉伸测试结果表明:ECAP4道次挤压后,合金的抗拉强度和伸长率由铸态的166MPa、1.64%提高为322MPa、21.7%;ECAP8道次挤压后,合金的伸长率继续提高为24.7%.但抗拉强度下降到293MPa.
재250℃하이Bc로경대Al-10Mg-4Si합금진행4도차화8도차적등통도전각제압,이구체도개선합금조직화제고합금역학성능적목적.소묘전자현미경(SEM)화투사전자현미경(TEM)대제압전후적미관조직분석표명:주태합금기체정립비교조대,제이상Mg_2Si이조대적한자상혹골격상분포우기체정계처;경ECAP제압후,기체정립득도세화,원조대적한자상Mg_2Si피쇄화위단봉상혹다변형상과립,병정일정적미산분포.실온랍신측시결과표명:ECAP4도차제압후,합금적항랍강도화신장솔유주태적166MPa、1.64%제고위322MPa、21.7%;ECAP8도차제압후,합금적신장솔계속제고위24.7%.단항랍강도하강도293MPa.
The Al-10Mg-4Si alloy Was pressed by ECAP through 4 and 8 passes at 250 ℃ in route Bc.The microstructures of the alloy before and after ECAP were investigated by scanning electron microscope (SEM) and transmission electron microscope(TEM).The mechanical properties at room temperature were measured by tension test.The experimental results show that the as-cast microstructure of the alloy is very coarse,with the large Chinese script or skeleton-shaped Mg_2Si distributed along the grain boundary;through ECAP,the matrix grain is significantly refined.The initial coarse Chinese-script-shape Mg_2Si is obviously broken into fine rod-shaped or polygonal particles and the distribution becomes more dispersed.The tensile strength and elongation of the alloy through ECAP 4 passes increase from 166 MPa and 1.64% in the as-cast alloy to 322 MPa and 21.7%,respectively;through 8 passes ECAP,the elongation further increases to 24.7%,but the tensile strength decreases to 293 MPa.