(1. 沈陽航空航天大學(xué) 材料科學(xué)與工程學(xué)院,沈陽 110136;
2. 中國科學(xué)院金屬研究所,沈陽 110016)
摘 要: 基于EBSD技術(shù)所測得晶粒的歐拉角,建立了Schmid因子計算公式,用來計算HCP晶體中單個晶粒的Schmid因子。在此基礎(chǔ)上,系統(tǒng)分析了鎂合金板材拉伸變形時晶粒取向變化與不同微觀變形模式的Schmid因子的關(guān)系。對鎂合金棒材中的基面織構(gòu)的Schmid因子分布特征進(jìn)行了計算分析,結(jié)合鎂合金棒材壓縮變形的實測結(jié)果,分析了鎂合金棒材壓縮變形的力學(xué)性能及鎂合金棒材徑向壓縮過程晶粒取向變化特征。結(jié)果表明:鎂合金板材中的基面織構(gòu)不利于基面滑移系和拉伸孿晶啟動,而利于柱面和錐面滑移系啟動,異步軋制對鎂合金板材力學(xué)性能的提升有限。晶粒Schmid因子分布的差異導(dǎo)致鎂合金棒材軸向和徑向壓縮時的微觀變形機(jī)制存在差異,從而導(dǎo)致宏觀力學(xué)性能差異明顯。
關(guān)鍵字: 鎂合金;變形機(jī)理;歐拉角;Schmid因子;織構(gòu)
(1. School of Materials Science and Engineering, Shenyang Aerospace University, Shenyang 110136, China;
2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract:Formula on the Schmid factor (SF) was established with the Euler angles measured by the electronic backscatter diffraction technique (EBSD), which could be applied to calculate the SFs of HCP structural materials. With this formula, the relationship between variation of grain orientation and SFs for different plastic deformation modes during the extension of magnesium alloy sheet was systematically analyzed. The results show that the existence of basal texture within the magnesium alloy sheet is not beneficial for activations of basal sliding and extension twin, but beneficial for activations of prismatic and pyramidal slips. The improvement of the mechanical properties of magnesium alloy sheet caused by the differential speed rolling is limited. The differences in activation of micro deformation mechanism between axial and radical compressions of magnesium alloy rod are caused by their distinctive SFs for grain, which correspondingly result in obviously different mechanical properties for two loading cases.
Key words: magnesium alloy; deformation mechanism; Euler angles; Schmid factor; texture


