本文選題：AZ鎂合金 + 純鋁　； 參考：《稀有金屬》2015年06期

【摘要】：采用反向擠壓技術(shù)將AZ31鎂合金和純鋁材料在不同溫度下擠壓形成包覆棒材。擠壓過(guò)程中純鋁包覆在鎂合金外側(cè),鎂鋁間形成冶金結(jié)合界面,實(shí)現(xiàn)了鎂鋁雙金屬的復(fù)合。擠壓完成后使用光學(xué)顯微鏡(OM)、掃描電子顯微鏡(SEM)及能譜(EDS)分析技術(shù)對(duì)鎂鋁包覆擠壓合金進(jìn)行了組織及力學(xué)性能分析,重點(diǎn)研究了鋁鎂合金結(jié)合界面處化學(xué)成分過(guò)渡及相結(jié)構(gòu)的演化與分布,同時(shí)采用顯微硬度計(jì)測(cè)試了鎂鋁結(jié)合界面的顯微硬度。結(jié)果表明,通過(guò)反向熱擠壓工藝可以得到表面光潔、無(wú)明顯缺陷的鋁鎂合金包覆擠壓制品。在高溫高壓條件下,鎂鋁復(fù)合金屬在界面結(jié)合區(qū)發(fā)生了元素?cái)U(kuò)散,鋁鎂合金濃度出現(xiàn)明顯的梯度變化,進(jìn)而在結(jié)合界面上發(fā)生冶金反應(yīng),形成約350μm厚的金屬間化合物層,物相分析表明在靠近鎂合金基體一側(cè)生成富鎂相Al12Mg17,靠近純鋁一側(cè)生成富鋁相Al3Mg2,主要為脆性相生成。沿包覆棒材橫截面直徑方向從邊部到芯部進(jìn)行顯微硬度測(cè)試,結(jié)果表明,該合金包覆型材具有明顯的力學(xué)不均勻性,在鋁鎂結(jié)合界面處的硬度高于兩側(cè)基體材料,其峰值硬度可達(dá)HV 200以上,包覆型材在結(jié)合界面的組織差異和強(qiáng)度、硬度失配導(dǎo)致結(jié)合界面的力學(xué)性能急劇弱化,容易產(chǎn)生開(kāi)裂。
[Abstract]:AZ31 magnesium alloy and pure aluminum alloy were extruded to form coated bar at different temperatures by reverse extrusion. During extrusion, pure aluminum was coated on the outside of magnesium alloy, and the metallurgical bonding interface was formed between magnesium and aluminum, thus the composite of magnesium and aluminum bimetallic was realized. The microstructure and mechanical properties of magnesia-aluminum-coated extruded alloy were analyzed by means of optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) after extrusion. The chemical composition transition and the evolution and distribution of phase structure at the interface of Al-Mg alloy were studied. The microhardness of the interface was measured by microhardness meter. The results show that aluminum magnesium alloy coated extrusion products with smooth surface and no obvious defects can be obtained by reverse hot extrusion process. Under the condition of high temperature and high pressure, the element diffusion occurs in the interface bonding zone, the concentration of Al-Mg alloy changes obviously, and then metallurgical reaction occurs at the interface, forming an intermetallic compound layer about 350 渭 m thick. Phase analysis shows that Al _ (12) mg _ (17) is formed near the base side of magnesium alloy, and Al _ (3) mg _ (2) is formed near the side of pure aluminum, which is mainly formed by brittle phase. The microhardness test was carried out along the cross section diameter of the coated bar from the edge to the core. The results show that the alloy coated profile has obvious mechanical inhomogeneity, and the hardness at the interface between aluminum and magnesium is higher than that at both sides. The peak hardness can reach HV200 or above. The microstructure and strength of the cladding profile at the interface are different. The mismatch of hardness leads to the sharp weakening of the mechanical properties of the interface and the cracking is easy to occur.
【作者單位】： 蘭州理工大學(xué)省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室;
【基金】：甘肅省科技重大專(zhuān)項(xiàng)項(xiàng)目(1203GKDJ004) 甘肅省青年科技基金項(xiàng)目(1308RJYA046)資助
【分類(lèi)號(hào)】：TG379;TB331

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本文編號(hào)：2113511