TiB2颗粒增强铝合金复合材料研究

为了避免传统铸锭的组织粗大与微观偏析影响材料强度的提升, 采用快速凝固单辊熔体旋转法制备5%TiB₂增强Al-Zn-Mg-Cu-Zr-Er复合材料薄带, 其中TiB₂颗粒的质量分数为5%, 在380~440 ℃温度下进行热力挤压获得复合材料棒材, 通过X射线衍射、扫描电镜、拉伸测试等分析手段研究TiB₂增强铝基复合材料显微组织与力学性能。结果表明: 快速凝固能明显细化复合材料晶粒, 组织均匀, 制备的TiB₂增强复合材料带材晶粒尺寸为4~6 μm; 细晶复合材料带材经热挤压得到棒材, TiB₂颗粒均匀分布; 随挤压温度升高, 复合材料棒材抗拉强度从381 MPa提升到445 MPa, 晶粒有所长大。综合考虑, 挤压温度420 ℃、保温30 min为最佳快速凝固+热挤压制备复合材料工艺参数。快速凝固技术在铝基复合材料晶粒细化方面有很大潜力。

Recent development in aluminium alloys for aerospace applications

To avoid the coarse microstructures and micro-segregation of traditional ingots affecting the improvement of material strength, a rapid solidification single-roll melt rotation method was used to prepare 5%TiB₂/Al-Zn-Mg-Cu-Zr-Er composite material ribbons, composite bars were obtained by hot extrusion at 380-440 ℃, and the microstructures and mechanical properties of TiB₂ reinforced aluminum matrix composites were studied by X-ray diffraction, scanning electron microscopy, tensile testing and other analytical methods. Results show that rapid solidification can significantly refine composite grains, microstructure uniformity, the grain size of the prepared TiB₂ reinforced composite ribbons are 4-6 μm; fine-grained composite ribbons are hot extruded to obtain bars, and TiB₂ particles are uniformly distributed. As the extrusion temperatures increase, the tensile strength of composite bars increases from 381 MPa to 445 MPa, and the grains have grown. The extrusion temperature of 420 ℃ for 30 min is the best rapid solidification and hot extrusion process parameter for preparing composites. Rapid solidification technology has great potential for grain refinement of aluminum matrix composites.