(1. 同濟大學(xué) 材料科學(xué)與工程學(xué)院
上海市金屬功能材料開發(fā)應(yīng)用重點實驗室，上海 200092；
2. 西南交通大學(xué) 牽引動力國家重點實驗室，成都 610031)
摘 要: 研究不同等效應(yīng)變幅下ZL101鋁合金在多軸比例和非比例載荷下的低周疲勞行為，并用透射電鏡觀察合金的疲勞行為中的位錯結(jié)構(gòu)。結(jié)果表明：合金在兩種加載方式下均表現(xiàn)為循環(huán)硬化；在非比例載荷下合金表現(xiàn)出附加強化，但程度不明顯；合金的疲勞壽命隨等效應(yīng)變幅的增加而降低，合金在非比例加載下的疲勞壽命低于比例加載時的疲勞壽命。對位錯結(jié)構(gòu)的觀察表明，隨等效應(yīng)變幅度的提高，合金的低周疲勞位錯結(jié)構(gòu)從交叉位錯帶轉(zhuǎn)化為位錯胞，合金在非比例加載下更易形成位錯胞結(jié)構(gòu)。
關(guān)鍵字: ZL101鋁合金；多軸低周疲勞；非比例載荷；循環(huán)硬化；位錯
under multi-axial loading
LIU Xiao-shan1, ZHANG Wei-hua2
（1. School of Materials Science and Engineering, Shanghai Key Laboratory for A & D of Metallic
Functional Material,Tongji University, Shanghai 200092, China;
2. National Power Traction Laboratory, Southwest Jiaotong University, Chengdu 610031, China）
Abstract: Multi-axial low cycle fatigue behavior of cast aluminum alloys ZL101 at different equivalent strain ranges under proportional and non-proportional loadings were studied, the dislocation substructures of ZL101 were observed by TEM. The results show that the aluminum alloy shows cyclic hardening both under multi-axial proportional and non-proportional loadings, while the cyclic additional hardening is shown under non-proportional loading, but the level is low. The multi-axial fatigue life decreases as the equivalent strain amplitude increases under both of multi-axial loadings. The fatigue life under non-proportional loading is less than that under proportional loading at the same equivalent strain amplitude. The deformation substructure examination reveals that with increasing equivalent strain amplitude, the dislocation structure tends to change from cross dislocation bands to dislocation cells. It is easier to form dislocation cells under non-proportional loading.
Key words: cast aluminum alloys ZL101; multi-axial low cycle fatigue; non-proportional loading; cyclic hardening; dislocation
