(1. 江蘇大學(xué)材料科學(xué)與工程學(xué)院，鎮(zhèn)江212013；
2.上海交通大學(xué)，密西根學(xué)院，上海 200240)
摘 要: 為了研究激光沖擊強(qiáng)化(LSP)對鎂合金力學(xué)性能的影響，采用電子萬能拉伸機(jī)和顯微硬度測試儀研究AZ31和AZ80D-T6鎂合金拉伸應(yīng)力-應(yīng)變曲線和顯微組織。結(jié)果表明：經(jīng)LSP處理后，AZ80-T6和AZ31合金的抗拉強(qiáng)度分別增加4.6%和15.7%，其表層硬度分別增加22.7%和31.8%；AZ31合金激光沖擊強(qiáng)化效果比AZ80D-T6合金的更加顯著，激光沖擊產(chǎn)生高幅殘余壓應(yīng)力和高密度孿晶以及細(xì)小片層狀、短棒狀或動態(tài)析出β相，晶粒細(xì)化形成超細(xì)晶，并討論預(yù)時(shí)效β析出相對鎂合金激光沖擊強(qiáng)化的影響和拉伸斷口特征。
關(guān)鍵字: 鎂合金；激光沖擊強(qiáng)化；應(yīng)力-應(yīng)變曲線；力學(xué)性能；顯微組織
（1. School of Materials Science and Engineering，Jiangsu University, Zhenjiang 212013, China;
2. Joint institute, University of Michigan- Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:In order to study the effect of laser shock processing (LSP) on mechanical properties of magnesium alloys, the tensile stress-strain curves and microstructures of AZ31 and AZ80D-T6 magnesium alloys were investigated by electronic universal tensile machine and microhardness test. The results show that after LSP, the tensile strengths of AZ80-T6 and AZ31 alloys increase by 4.6% and 15.7%, the surface hardnesses increase by 22.7% and 31.8%, respectively. The strengthening effect of LSP on AZ31 is more significant than that on AZ80D-T6. The LSP generates high value residual compressive stress and high-density twins as well as the fine lamellar or short columnar or dynamic precipitation β phases. The grains are refined and the ultrafine grains are formed. The effect of pre-aged β precipitates on LSP strengthening effect and tensile fracture characteristics were discussed.
Key words: magnesium alloy; laser shock processing; stress-strain curve; mechanical property; microstructure
