(哈爾濱理工大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150040)
摘 要: 在合金熔煉過(guò)程中通過(guò)控制磁場(chǎng)的施加，分別制備無(wú)電磁攪拌和施加電磁攪拌的Mg-2.0Zn-0.7Zr-0.5Ca鎂合金鑄錠。采用等通道擠壓(ECAP)工藝分別對(duì)這兩種狀態(tài)的合金進(jìn)行擠壓加工，研究電磁攪拌對(duì)ECAP前后合金組織和性能的影響。結(jié)果表明：與無(wú)磁場(chǎng)狀態(tài)相比，施加電磁攪拌后，合金的顯微組織和力學(xué)性能均得到很大改善。因電磁攪拌能細(xì)化鑄態(tài)合金的原始晶粒，經(jīng)1道次和2道次ECAP后合金的晶粒細(xì)化程度明顯優(yōu)于無(wú)磁場(chǎng)狀態(tài)的鑄態(tài)合金的。4道次ECAP后施加電磁攪拌合金的晶粒非常細(xì)小、均勻，且性能最佳，其硬度、屈服強(qiáng)度和伸長(zhǎng)率分別達(dá)到56.3 HV、276 MPa和18.3%。
關(guān)鍵字: Mg-Zn-Zr-Ca合金；電磁攪拌；等通道擠壓；顯微組織；力學(xué)性能
（School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China）
Abstract:Mg-2.0Zn-0.7Zr-0.5Ca alloy ingots with and without electromagnetic stirring were fabricated separately by controlling the application of the magnetic field in the casting process, and then were processed by the equal channel angular pressing (ECAP) technology. The effects of electromagnetic stirring on the microstructure and properties of the alloys before and after ECAP were studied. The results show that the microstructure and mechanical properties of the alloy with electromagnetic stirring are improved greatly compared with those of the alloy without electromagnetic stirring. Because electromagnetic stirring can refine the initial grain of the as-cast alloy, the grain refinement is obviously better than that of the as-cast alloy without electromagnetic stirring after 1 pass and 2 passes of ECAP. After 4 passes of ECAP, the grain size of the alloy with electromagnetic stirring becomes very small and uniform. At this time, the alloy has the best mechanical properties, and the microhardness, yield strength and elongation of the alloy reach 56.3HV, 276 MPa and 18.3%, respectively.
Key words: Mg-Zn-Zr-Ca alloy; electromagnetic stirring; equal channel angular pressing; microstructure; mechanical property
