(中南工業(yè)大學(xué)非平衡材料科學(xué)與工程研究所，長沙 410083)
摘 要: 采用多層噴射沉積技術(shù)制備6066鋁合金(Al-1.37Si-1.37Mn0.77Cu)錠坯，研究了后續(xù)半固態(tài)擠壓工藝的可行性，及其對材料組織與性能的影響。結(jié)果表明, 多層射噴沉積6066鋁合金的平均晶粒度約為15μm，呈等軸晶；在固相線以下退火40min后， 組織無明顯粗化， 在半固態(tài)發(fā)生的晶粒長大符合Ostwald晶粒粗化動力學(xué)方程， 半固態(tài)典型組織為球形或近球形的固體顆粒分布于液相中，為適宜于半固態(tài)加工的攪溶組織。 半固態(tài)擠壓成形力約為傳統(tǒng)熱擠壓的1／3， 擠壓件具有良好的第二相粒子分布狀態(tài)， 在T6熱處理過程中組織發(fā)生再結(jié)晶， 晶粒明顯細化，二相粒子平均粒度由熱擠壓態(tài)的1μm增至2μm， 體積分?jǐn)?shù)有所增加，材料力學(xué)性能達到傳統(tǒng)熱擠壓件水平。
關(guān)鍵字: 噴射沉積 半固態(tài) 鋁合金
（Non-equilibrium Materials Science and Engnieering Institute,
Central South University of Technology, Changsha 410083, P. R. China）
Abstract:6066 aluminum alloy billets(Al-1.37Si-1.37Mg-0. 77Cu) were produced by multi-layer spray deposition technology, studies were carried out to evaluate the feasibility of subsequent semi-solid extrusion and its influence on microstructure and mechanical properties. As-sprayed grain was equiaxed with mean size of about 15μm, grains coarsened slightly in full solid state, which are in good agreement with Ostwald coarsing mechanism. Typical microstructures of as-sprayed materials heated to semi-solid state are of spheriodical solid particles distributed in liquid phase, which are thixotropic microst ructure fit to thixoforming. The necessary extrusion force in semi-solid state is about 1/3 of that in coventional hot extrusion. As-extruded materials have uniform precipitates distribution and achieve finer recrystallization grains under T6 condition. Mean precipitated size increase from 1μm to 2μm after T6 treatment, and mechanical properties reach that of conventional hot extruded materials.
Key words: spray deposition semi-solid aluminum alloy near-net-shaping microstructure
