Ti-Al-C系复合材料的微观组织演变

Microstructure Evolution of Ti-Al-C System Composite

摘要:

以Ti粉、纯Al和碳纤维为原料，采用浸渗-反应合成法制备出Ti-Al-C系复合材料。首先将Ti粉和碳纤维制成预制件，再将熔融的纯Al压入预制件，制备出铸态的复合材料。随后将铸态的复合材料分别在600至1260 ℃间进行原位反应，保温时间为1 h。通过SEM和EDX 分析了复合材料的显微组织和产物的元素成分，同时，采用XRD分析复合材料的相组成。结果表明，在较低温下，TiAl3和Al4C3首先生成；随着温度的进一步升高，TiAl3 分解，TiC析出；在高温下，氧化现象发生，有Al2O3生成。Ti-Al-C系复合材料在原位反应过程中遵循生成-分解-析出-氧化机制。

Abstract:

Ti-Al-C composite was fabricated by infiltration-in situ reaction. The as-cast material was prepared by pressing molten pure aluminum into the preform composed of titanium particles and carbon fibers. In situ reacted samples were obtained by heating the as-cast material from 600 to 1000 oC, and holding for 1 h at different temperatures. The morphology and elemental composition of samples were analyzed by scanning electron microscope and Energy dispersive X-ray, respectively. In addition, the phase composition of products was inspected by X-ray diffraction. Results show that TiAl3 and Al4C3 are formed at low temperature; with increasing of temperature, TiAl3 decomposes and TiC precipitates; at high temperature, the oxidation occurs resulting in the formation of Al2O3. The mechanism of Ti-Al-C system composite during in situ reaction procedure is as following: formation-decomposition-precipitation-oxidation.