凝固速率对Al3Ti/Al复合材料显微组织的影响
Effects of Solidification Rate on Microstructure of Al3Ti/Al Composite
吴志锋, 陈 刚, 赵玉涛, 张 勇
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作者单位：江苏大学 材料科学与工程学院, 江苏 镇江 212013
中文关键字：凝固速率； Al3Ti； 铝基复合材料； 显微组织
英文关键字：solidification rate; Al3Ti; aluminum matrix composite; microstructure
中文摘要：以Al-Ti为反应体系，采用熔体反应法原位合成Al3Ti/Al复合材料，并采用XRD、SEM等方法研究了凝固速率对该复合材料显微组织的影响。结果表明，不同凝固速率对Al3Ti颗粒的形貌及尺寸有较大的影响，在较慢凝固速率砂型模浇注制备的复合材料中，Al3Ti呈长针状，长度在50～150 μm；在较快凝固速率铜模浇注制备的复合材料中，Al3Ti呈短棒状，长度在10 μm左右，但在铜模凝固层最薄处的组织中，Al3Ti呈四角形状，尺寸在10 μm以下；随着凝固速率的增加，Al3Ti/Al复合材料的晶粒尺寸逐渐减小。
英文摘要：In-situ Al3Ti/Al composite was fabricated by direct melt reaction method in Al-Ti system. The microstructure of the composite at various solidification rates was studied by XRD and SEM. The results show that the morphology and size of Al3Ti particles are obviously affected by various solidification rates. The morphology of Al3Ti particle is needle-like with the length of 50～150 μm in the composite which is fabricated by sand mould at low solidification. While it is short rod-like and nearly 10 μm in size when the composite is casted by cooper mold at rapid solidification. But in the thinnest of the composite, the Al3Ti particle is four-angle star in shape and below 10 μm in size. Additionally, the crystal grain size of the composite decreases with solidification rate increasing.