Abstract Direct laser deposition of a mixture of titanium (Ti) and boron-carbide (B4C), using the laser engineered net shaping process, results in a complex multi-phase Ti matrix composite due to the incipient interfacial reactions between liquid titanium and solid/partially melted B4C. Detailed microstructural characterization, at multiple length scales, reveals that titanium boride (TiB) precipitates are the initial reaction product which act as heterogeneous nucleation sites for TiC precipitates. Both the TiB and TiC precipitates in turn act as heterogeneous nucleation sites for fine β-Ti grains, within the retained liquid titanium, which eventually transform into fine equiaxed α-Ti grains comprising the matrix.

中文翻译：

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Ti-B4C 复合材料直接激光沉积过程中的原位反应

摘要 钛 (Ti) 和碳化硼 (B4C) 混合物的直接激光沉积，使用激光工程净成形工艺，由于液态钛和固态/部分熔化的 B4C。在多个长度尺度上的详细微观结构表征表明，硼化钛 (TiB) 沉淀物是初始反应产物，可作为 TiC 沉淀物的异质成核位点。TiB 和 TiC 析出物反过来作为细 β-Ti 晶粒的异质成核位点，在保留的液态钛中，最终转变为包含基体的细等轴 α-Ti 晶粒。