發(fā)布時間：2018-06-22 19:11

  本文選題：Al-Mn中間合金 + AM合金��； 參考：《武漢科技大學(xué)》2016年碩士論文

【摘要】：鎂合金具有質(zhì)量輕、比強度高、減振性能好以及可回收利用等方面的優(yōu)勢,使其在汽車工業(yè)中的應(yīng)用正快速增長。AM60鎂合金由于制造成本低、工藝性能好,是應(yīng)用較廣泛的一類鑄造鎂合金,但該合金的高溫性能差,阻礙了其應(yīng)用范圍,因此提高合金的高溫性能成為廣大鎂合金工作者感興趣的研究課題。本研究首先制備了兩種成分的Al-Mn中間合金,然后在鎂液中添加中間合金制備AM60A和AM61A鎂合金。采用光學(xué)金相分析,SEM及能譜分析研究了鎂合金的顯微組織及相成分,對鎂合金進(jìn)行室溫和高溫拉伸試驗,研究了Al-Mn中間合金對AM合金力學(xué)性能的影響,結(jié)合固溶及時效組織分析了Al-Mn中間合金提高AM合金高溫性能的原因。研究結(jié)果表明:添加Al-Mn中間合金能夠有效改善AM合金組織中β-Mg17Al12形態(tài)和分布,減少了粗大共晶β-Mg17Al12相數(shù)量和尺寸,增加了顆粒狀的β-Mg17Al12相,鎂合金的室溫力學(xué)性能明顯提高;同時,加快冷卻速度可以細(xì)化鎂合金的晶粒尺寸;Al-Mn相是一種熱穩(wěn)定的高溫相,450℃,45小時保溫也不能使其溶解,因此添加Al-Mn中間合金能夠明顯提高AM合金的高溫強度;AM合金在250℃時效處理時還可以形成許多細(xì)小顆粒狀耐高溫相,有利于AM合金高溫性能的提高,AM61A合金由于含有更多的Al-Mn組織,因而高溫強度最高。
[Abstract]:Magnesium alloy has the advantages of light weight, high specific strength, good vibration absorption performance and recyclable utilization. The application of AM60 magnesium alloy in automobile industry is increasing rapidly because of its low manufacturing cost and good process performance. It is a kind of casting magnesium alloy which is widely used, but the high temperature property of the alloy is poor, which hinders its application scope. Therefore, improving the high temperature property of the alloy has become an interesting research topic for many magnesium alloy workers. In this study, two kinds of Al-Mn master alloys were prepared firstly, and then AM60A and AM61A magnesium alloys were prepared by adding master alloys to magnesium solution. The microstructure and phase composition of magnesium alloy were studied by optical metallographic analysis (SEM) and energy dispersive spectrum (EDS). The tensile tests at room and high temperature were carried out on the magnesium alloy. The effect of Al-Mn master alloy on the mechanical properties of AM alloy was studied. The reason of improving the high temperature properties of AM alloy by Al-Mn master alloy was analyzed in combination with solution and aging microstructure. The results show that the addition of Al-Mn master alloy can effectively improve the morphology and distribution of 尾 -Mg17Al12 in AM alloy, decrease the number and size of coarse eutectic 尾 -Mg17Al12 phase, increase the granular 尾 -Mg17Al12 phase, and improve the mechanical properties of magnesium alloy at room temperature. The grain size of magnesium alloy can be refined by increasing the cooling rate. The Al-Mn phase is a kind of thermostable high-temperature phase, which can not be dissolved by 45 hours of heat preservation at 450 鈩，

本文編號：2053927