In this study, TiB₂/7075 aluminum matrix composites were prepared via in situ synthesis. It was found that TiB₂ particles are mainly quadrate. Large TiB₂ particles (1–2 μm) agglomerate at grain boundaries, but most of the particles are on the submicron scale. Adding 4.5 wt.% TiB₂ particles effectively optimizes α-Al grains in the 7075 aluminum alloy. By combining in situ reinforcing particles with the self-stirring effect of a serpentuator, rheocasting of the 7075 aluminum alloy was achieved in a simple and economical way. The average grain size of the specimen after rheocasting and heat treatment was smaller than 33 μm, and the shape factors were greater than 0.85. The wear resistance of the 4.5 wt.% TiB₂/7075 aluminum matrix composite that was prepared via rheocasting and gravity casting was tested with loads of 30, 60, 90, and 120 N at a friction speed of 0.15 m/s for a duration of 30 min. Because of the optimized microstructure and increased hardness, the wear resistance of the 4.5 wt.% TiB₂/7075 aluminum matrix composite was significantly better than that of the 7075 aluminum alloy, and the wear resistance of the rheocast TiB₂/7075 aluminum matrix composite was better than that of the gravity cast one.

中文翻译：

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流变浇铸法制备的TiB2 / 7075复合材料的组织和耐磨性

在这项研究中，的TiB ₂分别通过原位合成制备/ 7075铝基复合材料。发现TiB ₂颗粒主要为方形。较大的TiB ₂颗粒（1-2μm）在晶界聚集，但大多数颗粒处于亚微米级。添加4.5 wt。％TiB ₂颗粒可有效优化7075铝合金中的α-Al晶粒。通过将原位增强颗粒与蛇形管的自搅拌作用结合在一起，可以以一种简单而经济的方式实现7075铝合金的流变铸造。流变铸造和热处理后的样品的平均晶粒尺寸小于33μm，形状因子大于0.85。4.5 wt。％TiB ₂的耐磨性通过流变铸造和重力铸造制备的/ 7075铝基复合材料在0.15 m / s的摩擦速度下以30、60、90和120 N的载荷进行了30分钟的测试。由于优化的微观结构和增加的硬度，4.5重量的耐磨损性的。％的TiB ₂ /7075铝基复合材料是显著更好小于7075铝合金，以及rheocast的TiB的耐磨性₂ /7075铝基复合材料比重力铸造的要好。