發(fā)布時間：2019-01-28 19:43

【摘要】：7A85鋁合金密度小、強度高、熱加工性能好、焊接性能優(yōu)良,而且具有較好的耐腐蝕性和較高的韌性,廣泛應(yīng)用于航空和航天中的受力結(jié)構(gòu)件.本文通過擠壓態(tài)7A85鋁合金的單向等溫?zé)釅嚎s實驗,利用光學(xué)顯微鏡、透射電鏡研究了合金在變形溫度為300℃,350℃,400℃,450℃,應(yīng)變速率為0.01s~(-1),0.1s~(-1),1s-1,10s~(-1)時的高溫流變行為和顯微組織演變.結(jié)果表明:變形溫度和應(yīng)變速率對擠壓態(tài)7A85鋁合金熱壓縮后的組織有重要影響.隨著變形溫度的升高和應(yīng)變速率的降低(lnZ減小),組織中亞晶長大,位錯密度逐漸降低,析出相數(shù)量減少,再結(jié)晶晶粒長大,動態(tài)軟化機制由動態(tài)回復(fù)轉(zhuǎn)變?yōu)閯討B(tài)再結(jié)晶;擠壓態(tài)7A85鋁合金熱壓縮后組織中大量的析出相彌散分布在基體內(nèi)或沿晶界分布,抑制了動態(tài)再結(jié)晶的發(fā)生.
[Abstract]:7A85 aluminum alloy has the advantages of low density, high strength, good hot working property, good welding property, good corrosion resistance and high toughness, so it is widely used in aeronautics and spaceflight. In this paper, the unidirectional isothermal compression experiment of extruded 7A85 aluminum alloy was carried out. The deformation temperature of the alloy was 300 鈩，

本文編號：2417257