(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究噴射沉積Al-27%Si合金的半固態(tài)擠壓成形工藝及其對合金組織與性能的影響。結(jié)果表明：噴射沉積Al-27%Si合金在600 ℃下二次加熱10~12 min后，合金液相體積分?jǐn)?shù)適中，Si相尺寸相對細(xì)小，形貌為近球形，適合于半固態(tài)成形。經(jīng)600 ℃二次加熱10~12 min后，進(jìn)行半固態(tài)擠壓能消除噴射沉積合金中的孔隙，Si相比擠壓前更加均勻細(xì)小，擠壓棒材具有良好的表面質(zhì)量和均勻的微觀組織。經(jīng)600 ℃二次加熱12 min后，半固態(tài)擠壓的合金可達(dá)到最高的相對密度(99.5%)、抗拉強(qiáng)度(195 MPa)和伸長率(6.7%)。
關(guān)鍵字: Al-27%Si合金；噴射沉積；二次加熱；半固態(tài)擠壓；抗拉強(qiáng)度；相對密度
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The semi-solid extrusion and its effect on the microstructure and properties of spray deposited Al-27%Si alloy were studied. The result shows that, the alloy have appropriate liquid volume fraction and fine Si particles for semi-solid extrusion after reheating at 600 ℃ for 10-12 min. The extrusion after reheating at 600 ℃ for 10-12 min can eliminate the hole in the spray deposited alloy and decrease the size of Si particles, extruded bars have good surface quality and homogeneous microstructure after extrusion. The alloy can achieve the highest relative density (99.5%), tensile strength (195 MPa) and elongation (6.7%) after semi-solid extrusion when reheating at 600 ℃ for 12 min.
Key words: Al-27%Si alloy; spray depositing; reheating treatment; semi-solid extrusion; tensile strength; relative density
