發(fā)布時間：2018-07-08 10:01

  本文選題：2A14鋁合金 + 擠壓比�。� 參考：《哈爾濱理工大學》2017年碩士論文

【摘要】：本文通過熱擠壓實驗、熱處理實驗、金相顯微組織觀察、掃描(SEM)顯微組織觀察、能譜分析、透射(TEM)電鏡觀察、力學性能測試等方法對2A14鋁合金進行研究。研究了不同擠壓比下合金組織及力學性能的變化以及熱處理制度對合金組織及性能產(chǎn)生的影響。實驗結(jié)果表明,熱擠壓過程中合金組織發(fā)生動態(tài)再結(jié)晶,合金內(nèi)位錯密度較低;熱擠壓對合金的強化作用是形變強化與動態(tài)再結(jié)晶共同作用的結(jié)果,第二相通過釘扎位錯和晶界來延緩動態(tài)再結(jié)晶速度;隨著擠壓比的增大,合金組織呈現(xiàn)均勻分布,第二相顆粒也隨之均勻分布且尺寸更加細小,形變強化作用增強,對材料的力學性能提升效果明顯;擠壓態(tài)的2A14鋁合金的主要強化相為 θ(Al_2Cu)、Mg_2Si 以及 ω(Cu_4Mg_5Si_4Alx),主要的雜質(zhì)相為(FeMnSi)Al_6 或(FeMn)Al_6;熱處理工藝中四個影響因素對合金抗拉強度的影響效果從大到小依次為:時效時間、固溶溫度、時效溫度、固溶時間,研究發(fā)現(xiàn)固溶溫度越高,第二相顆粒溶入基體的比例越大,對后續(xù)的時效強化提供了有利條件;時效處理后,Cu元素大量析出,Mg元素含量也有所增加,在合金基體上形成θ相與S(Al_2CuMg)相,并可能含有少量ω相。這些強化相分布十分均勻且尺寸細小,對合金強化起重要作用。實驗證明:在擠壓比為36:1的條件下,材料經(jīng)過505 ℃×1.5 h固溶處理、30℃-50℃水淬、160℃×8 h時效處理后,材料的抗拉強度和伸長率分別達到 352.7 MPa 和 15.3%。
[Abstract]:In this paper, 2A14 aluminum alloy was studied by means of hot extrusion, heat treatment, metallography, scanning, energy dispersive analysis, transmission electron microscope and mechanical properties. The microstructure and mechanical properties of the alloy under different extrusion ratios and the effect of heat treatment on the microstructure and properties of the alloy were studied. The experimental results show that dynamic recrystallization occurs in the microstructure of the alloy during hot extrusion, and the dislocation density in the alloy is low, and the strengthening effect of hot extrusion on the alloy is the result of both deformation strengthening and dynamic recrystallization. The second phase delays the dynamic recrystallization rate by pinning dislocations and grain boundaries. With the increase of extrusion ratio, the microstructure of the alloy is uniformly distributed, and the second phase particles are uniformly distributed and the size of the second phase particles is smaller, and the deformation strengthening effect is enhanced. The main strengthening phases of extruded 2A14 aluminum alloy are 胃 (Al2Cu) Mg2Si and 蠅 (Cu4Mg5Si4Alx), the main impurity phases are (FeMnSi) Al_6 or (FeMn) Al6.The effects of four factors on the tensile strength of the alloy are as follows: aging time, solid solution temperature, It was found that the higher the solution temperature, the higher the proportion of the second phase particles dissolved into the matrix, which provided favorable conditions for the subsequent aging strengthening. 胃 phase and S (Al2CuMg) phase are formed on the alloy matrix and may contain a small amount of 蠅 phase. These strengthening phases are uniformly distributed and small in size, and play an important role in strengthening the alloy. The results show that when the extrusion ratio is 36:1, the tensile strength and elongation of the material can reach 352.7 MPA and 15.3 MPA respectively after 30 鈩，

本文編號：2107064