在应变速率为0.001s(-1)和0.1s(-1),温度为150-300℃的条件下,采用热模拟对ZA73镁合金的高温拉伸变形行为进行了研究,并结合显微组织观察和挤压试验,分析确定了适合该合金的热加工工艺.结果表明:变形温度和应变速率是影响ZA73合金流变应力和塑性的关键参数,应变速率一定时,流变应力随温度的增加而降低;温度一定时,流变应力随应变速率的提高而增加.低应变速率下,温度高于200℃塑性反而降低;高应变速率下,合金的塑性随着温度的增加而提高,但在250℃时塑性出现反常变化.在200-250℃范围内变形时,铸态枝晶网状组织特征消失,第二相化合物呈颗粒状弥散分布于基体中,尺寸明显细化;300℃变形时,低应变速率下合金组织明显粗大.细小第二相粒子增多和组织粗化导致合金热塑性降低.较高的应变速率和较高的温度有利于合金的热变形.在350℃和较高应变速率(约0.1s(-1))下,挤压棒材的抗拉强度达355MPa,延伸率仍保持19%,晶粒尺寸细化至3-6μm.
参考文献
| [1] | N. Balasubramani;A. Srinivasan;U.T.S. Pillai .Effect of antimony addition on the microstructure and mechanical properties of ZA84 magnesium alloy[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2008(1/2):168-173. |
| [2] | ZHANG J;ZUO R L;CHEN Y X et al.Microstructure evolution during homogenization of a-type Mg-Zn-Al alloy[J].Journal of Alloys and Compounds,2008,448(1-2):316-320. |
| [3] | Zhan Zhang;Alain Couture;Alan Luo .An investigation of the properties of Mg-Zn-Al alloys[J].Scripta materialia,1998(1):45-53. |
| [4] | Oh-Ishi, K;Hono, K;Shin, KS .Effect of pre-aging and Al addition on age-hardening and microstructure in Mg-6 wt% Zn alloys[J].Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing,2008(1/2):425-433. |
| [5] | REN Y P;QIN G W;PEI W L et al.The a-Mg solvus and isothermal section of Mg-rich comer in the Mg-Zn-Al ternary system at 320℃[J].Journal of Alloys and Compounds,2009,481(1-2):176-181. |
| [6] | ZHANG J;HE Q B;PAN F S et al.Effects of erbium on the microstructure and mechanical properties of as-cast Mg-7Zn-3Al alloy[J].Transactions of Nonferrous Metals Society of China,2008,A01:22-26. |
| [7] | 张静,潘复生.金属型铸造ZA73镁合金凝固特征和组织研究[J].材料热处理学报,2006(03):68-70. |
| [8] | KUBOTA K;MABUCHI M;HIGASHI K .Processing and mechanical properties of fine-grained magnesium alloys[J].Journal of Materials Science,1999,34(10):2255-2262. |
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