SiC对流变轧制Mg-3Sn-1Mn-xSiC复合材料组织性能的影响

Effect of SiC on microstructure and property of Mg-3Sn-1Mn-xSiC composite prepared by rheo-rolling

利用剪切/搅拌与流变轧制制备了Mg-3Sn-1Mn-xSiC(质量分数/%)复合板材,研究了SiC对流变轧制Mg-3Sn-1Mn-xSiC复合材料组织性能的影响.结果表明:经过活化处理的SiC颗粒在Mg-3Sn-1Mn-xSiC复合材料内部分布较均匀;SiC颗粒可促进Mg-3Sn-1Mn-xSiC复合材料在凝固过程中Mg2Sn相异质形核,Mg2Sn相在SiC颗粒表面形核长大;同时,SiC颗粒可促进Mg-3Sn-1Mn-xSiC复合材料在凝固过程中α-Mg晶粒的细化与球化,随着SiC含量增加,α-Mg晶粒平均直径和圆度逐渐减小.制备的Mg-3Sn-1Mn-10SiC复合板材抗拉强度和伸长率分别达到242±4MPa和7.6±0.3%,比相同条件下制备的Mg-3Sn-1Mn合金板材的抗拉强度和伸长率分别提高了38%和36%.

Mg-3Sn- 1Mn- xSiC （mass fraction/% ） composite strip was prepared by stirring and rheo- rolling, and the effect of SiC on microstructure and property of Mg - 3Sn - 1Mn - xSiC composite was investigated. The results indicated that distribution of the activated SiC particles is uniform in the Mg - 3Sn - 1Mn - xSiC composite. SiC particle could promote heterogeneous nucleation of Mg2 Sn phase during solidification of Mg - 3 Sn - 1Mn - xSiC composite, and Mg2Sn phase could nucleate and grow on SiC surface. In addition, SiC particle could promote refinement and nodularizalion ofce - Mg grain during solidification. With increase of SiC content, the average diameter and roundness of ee - Mg grain decrease. The tensile strength and elongation of Mg - 3Sn - 1Mn - 10SIC composite strip reache 242 ＋ 4 MPa and 7.6 ＋ 0. 3 % which are increased by 38 % and 36 % respectively compared with that of Mg- 3 Sn -1 Mn alloy strip prepared by the same process.