【摘要】：隨著汽車工業(yè)的蓬勃發(fā)展,汽車產(chǎn)業(yè)正朝著輕量化、高速、舒適、節(jié)能、低排放的方向高速前進(jìn),越來越多的汽車采用高性能的鋁合金替代鋼、鐵等傳統(tǒng)材料,特別是在制造汽車發(fā)動機(jī)缸體、缸蓋等零部件方面。鑄造鋁硅合金由于其具有良好的綜合力學(xué)性能、成型加工性能等,成為鋁合金中使用較廣泛的一種合金系,然而普通鑄造鋁硅合金的力學(xué)性能較低,提高鋁硅合金的力學(xué)性能就成為迫切需要解決的問題。本文就是針對鑄造鋁硅合金系中的ADC12鋁合金,通過對其進(jìn)行合金化、熔體處理及熱處理研究,以達(dá)到改善ADC12鋁合金的顯微組織,提高其綜合力學(xué)性能的目的。本課題根據(jù)鋁合金材料的強(qiáng)韌化原理,以ADC12合金的成分范圍為研究基礎(chǔ),通過采用單項(xiàng)及正交實(shí)驗(yàn)法對合金化元素進(jìn)行成分優(yōu)化設(shè)計(jì),獲取合金的最佳成分配比為:11Si,2.5Cu,0.3Mg,0.5Mn,0.5Ni;同時(shí)對優(yōu)化后的合金進(jìn)行熔體處理工藝研究,研究表明,優(yōu)化后的ADC12合金經(jīng)0.06%Sr的變質(zhì)處理、0.15%Ti的細(xì)化處理后,合金的顯微組織發(fā)生顯著的改善,呈塊狀及枝狀的硅相變成規(guī)整的纖維狀或顆粒狀,塊狀的α(Al)相變成均勻的短桿狀,有力地提高了合金的力學(xué)性能,鑄態(tài)下其力學(xué)性能可達(dá)到:σ=254Mpa,δ=5.8%。本文還研究了不同的熱處理工藝對ADC12鋁合金組織與力學(xué)性能的影響,研究結(jié)果表明,其最佳的熱處理工藝參數(shù)為:510℃×7h+160℃×8h。優(yōu)化后的ADC12合金經(jīng)此熱處理工藝后,合金的顯微組織變的十分均勻,晶粒變得非常細(xì)小、圓整,拉伸斷口幾乎呈細(xì)小的等軸韌窩形貌,此時(shí)的合金力學(xué)性能高達(dá):σ=385Mpa,δ=8.2%。
[Abstract]:With the vigorous development of automobile industry, automobile industry is moving towards the direction of lightweight, high speed, comfort, energy saving and low emission. More and more cars adopt high performance aluminum alloy instead of steel, iron and other traditional materials. Especially in the manufacture of automobile engine cylinder block, cylinder head and other parts. The cast Al-Si alloy has become a kind of widely used alloy system because of its good comprehensive mechanical properties and processing properties, but the mechanical properties of the common cast Al-Si alloy are relatively low. It is an urgent problem to improve the mechanical properties of Al-Si alloy. In this paper, the microstructure of ADC12 aluminum alloy and the comprehensive mechanical properties of ADC12 aluminum alloy are improved by alloying, melt treatment and heat treatment. Based on the principle of strengthening and toughening of aluminum alloy and the composition range of ADC12 alloy, the composition optimization design of alloying elements is carried out by single and orthogonal experiment. The optimum composition ratio of the obtained alloy is: 1 / 11Si-2.5CuP0. 3Mg0. 5Mn0. 5Ni. at the same time, the melt treatment process of the optimized ADC12 alloy is studied. The results show that the microstructure of the optimized ADC12 alloy has been significantly improved after the modification of 0.06%Sr with 0.15Ti. The bulk and dendritic silicon phase becomes regular fibrous or granular, and the block 偽 (Al) phase becomes a uniform short rod, which increases the mechanical properties of the alloy by force. The mechanical properties of the as-cast alloy can be achieved as follows: 蟽 (254MPA), 未 (5.8cm). The effect of different heat treatment processes on the microstructure and mechanical properties of ADC12 aluminum alloy was also studied. The results showed that the optimum heat treatment process parameters were: 1: 510 鈩，

本文編號：2209103