延性斷裂的耦合影響
(1. 西安理工大學(xué) 材料科學(xué)與工程學(xué)院，西安 710048；
2. 西安交通大學(xué) 材料科學(xué)與工程學(xué)院 金屬材料強度國家重點實驗室，西安 710049；
3. 中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 針對Al-Mg-Si合金采用不同固溶處理和時效處理獲得粗大第二相顆粒與析出相顆粒之間體積分數(shù)的相對變化，研究粗大第二相顆粒與析出相顆粒對合金斷裂應(yīng)變的耦合影響。結(jié)果表明：兩種顆粒間含量的相對變化對Al-Mg-Si合金斷裂應(yīng)變的影響呈非單調(diào)性，粗大第二相顆粒含量較高的合金經(jīng)較高溫度時效時，其斷裂應(yīng)變值高于粗大第二相含量較低但經(jīng)較低溫度時效的合金的斷裂應(yīng)變值。根據(jù)強韌化效果相對變化對此試驗現(xiàn)象進行分析討論，采用多尺度斷裂模型很好地模擬了該兩相顆粒對斷裂應(yīng)變的耦合影響。
關(guān)鍵字: Al-Mg-Si合金；第二相；析出相；斷裂應(yīng)變
ductile fracture of Al-Mg-Si alloys
（1. School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China;
2. State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering,
Xi’an Jiaotong University, Xi’an 710049, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Different solution, quenching and aging treatments, inducing a trade-off between the constituents and precipitates, were employed to Al-Mg-Si alloys in order to study the coupling effect of the trade-off in volume fraction on the fracture strain. The results show that the dependence of ductility on the trade-off in volume fraction between the constituents and precipitates is non-monotonic, and that the alloys containing more detrimental constituents but aged at a somewhat higher temperature exhibit ductility superior to those of the alloys containing less detrimental constituents but aged at lower temperature. The experimental phenomena above are analyzed according to the change-over in strength and toughness, furthermore, the coupling effect of the constituents and precipitates on the strain to fracture is well modeled by using multi-scale model.
Key words: Al-Mg-Si alloy; constituent; precipitate; fracture strain
