發(fā)布時間：2019-01-21 10:47

【摘要】：采用光學(xué)顯微鏡(OM)、掃描電鏡(SEM)、X射線衍射(XRD)以及差示掃描量熱儀(DSC)等技術(shù)對車用鑄態(tài)7055鋁合金組織及均勻化退火過程中的組織演變進(jìn)行研究。結(jié)果表明:均勻化退火后鋁合金枝晶間距明顯縮小,晶粒細(xì)化。部分金屬間化合物以及許多非平衡共晶組織出現(xiàn)在晶界部位,呈現(xiàn)網(wǎng)狀片層的連續(xù)分布結(jié)構(gòu),在鑄態(tài)組織內(nèi)生成了具有較高Zn、Cu、Mg含量的共晶相。MgZn_2相隨著均勻化退火時間增加發(fā)生回溶現(xiàn)象。將均勻化退火時間增加到40 h,表現(xiàn)出明顯的均勻化效果。確定465℃下處理40 h作為最優(yōu)的單級均勻化條件。
[Abstract]:The microstructure evolution of as-cast 7055 aluminum alloy during homogenization annealing was studied by means of optical microscope (OM), scanning electron microscope (SEM), X ray diffraction (XRD) and differential scanning calorimeter (DSC). The results show that after homogenization annealing, the dendrite spacing of aluminum alloy is obviously reduced and the grain size is refined. Some intermetallic compounds and many non-equilibrium eutectic structures appear at grain boundaries, showing a continuous distribution structure of netlike lamellae. In the as-cast structure, high Zn,Cu, is formed. The eutectic phase with Mg content and MgZn_2 phase redissolve with the increase of homogenization annealing time. When the homogenization annealing time is increased to 40 h, the homogenization effect is obvious. The optimal single stage homogenization condition was determined at 465 鈩，

本文編號：2412585