V合金化对Al-9Si合金凝固组织与力学性能的影响  

Effect of V Alloying on the Solidification Microstructure and Mechanical Properties of Al-9Si Alloy

作　　者：席卫国 陈旭 陈吉 程婧璠[1] 蔡启舟[1] XI Weiguo;CHEN Xu;CHEN Ji;CHENG Jingfan;CAI Qizhou(State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074

出　　处：《铸造技术》2024年第3期279-287,共9页Foundry Technology

基　　金：国家自然科学基金(52075198)。

摘　　要：研究了V合金化对Al-9Si合金凝固过程、微观组织和力学性能的影响。结果表明,在Al-9Si合金中添加V,析出化合物Si_(2)V,而无AlV化合物析出,V对初生α-Al的析出温度无明显影响。随着V量增加,Al-9Si合金的初生α-Al的形核温度和形核过冷度同步增加,0.4%V(质量分数)使形核温度由未添加V的607.5℃上升至612.6℃,过冷度由24℃增加至27.1℃;继续增加V量,形核温度略有升高,但形核过冷度略有减小。V添加使Al-9Si合金初生α-Al晶粒形态由枝晶向等轴晶转变,Al-9Si-0.4V合金的α-Al晶粒尺寸由Al-9Si的593μm细化至302μm。V对共晶Si无变质作用,但V能使针状β-Al_(5)FeSi转变为鱼骨状的Al_(12)(Fe,V)_(3)Si相。0.6%Sb(质量分数)变质Al-9Si-0.4V合金的抗拉强度、屈服强度和伸长率为153.9 MPa、78.5 MPa和6.56%,较Al-9Si合金分别提高23.8%、14.1%和102.4%;硬度由47.3 HV提高至59.1 HV。Al-9Si合金的拉伸断口由撕裂棱和解理台阶组成,而Al-9Si-0.4V-0.6Sb合金断口中的解理台阶显著减少,撕裂棱变得更加致密,出现了以共晶Si为中心的韧窝,呈混合断裂特征。The effect of V alloying on the solidification process,microstructure,and mechanical properties of an Al-9Si alloy was investigated.The results show that when V is added to the Al-9Si alloy,the Si_(2)V phase precipitates,but no AlV phase precipitates,and V has no obvious effect on the precipitation temperature of the primaryα-Al.With increasing V content,the nucleation temperature and supercooling of the primaryα-Al particles in the Al-9Si alloy increase simultaneously.By adding 0.4 wt.%V,the nucleation increases from 607.5℃for Al-9Si to 612.6℃,and the supercooling increases from 24℃to 27.1℃.With increasing V content,the nucleation temperature slightly increases,but the nucleation supercooling slightly decreases.A transition from columnar to equiaxed growth occurs when V is added to the Al-9Si alloy.Theα-Al grain size of the Al-9Si-0.4V alloy is refined from 593μm for Al-9Si to 302μm.V has no modifying effect on the eutectic Si,but V could cause the transformation of needle-shapedβ-Al_(5)FeSi to fishbone-shaped Al_(12)(Fe,V)_(3)Si.The tensile strength,yield strength and elongation of the 0.6 wt.%Sb-modified Al-9Si-0.4V alloy are 153.9 MPa,78.5 MPa and 6.56%,respectively,which are 23.8%,14.1%and 102.4%greater than those of the Al-9Si alloy.The hardness increases from 47.3 HV to 59.1 HV.The fracture morphology of the Al-9Si alloy is composed of tearing edges and cleavage steps,while the cleavage steps of the Al-9Si-0.4V-0.6Sb alloy are significantly reduced,the tearing edges become denser,and dimples with eutectic Si as the center appear,revealing mixed fracture features.

关 键 词：Al-9Si合金 V合金化 凝固过程 微观组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—金属材料]