(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究喷射沉积Al-27%Si合金的半固态挤压成形工艺及其对合金组织与性能的影响。结果表明：喷射沉积Al-27%Si合金在600 ℃下二次加热10~12 min后，合金液相体积分数适中，Si相尺寸相对细小，形貌为近球形，适合于半固态成形。经600 ℃二次加热10~12 min后，进行半固态挤压能消除喷射沉积合金中的孔隙，Si相比挤压前更加均匀细小，挤压棒材具有良好的表面质量和均匀的微观组织。经600 ℃二次加热12 min后，半固态挤压的合金可达到最高的相对密度(99.5%)、抗拉强度(195 MPa)和伸长率(6.7%)。
关键字: Al-27%Si合金；喷射沉积；二次加热；半固态挤压；抗拉强度；相对密度
（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
