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采用同轴送粉方式和Ni/Al-WC-TiC复合粉末,用大功率CO_2激光器合成了(W,Ti)C颗粒增强的NiAl金属间化合物。用能谱仪、X射线衍射仪和扫描电镜分析了合成材料的成分、相和组织。结果表明,合成材料的化学计量比为Ni-35Al-18Fe-W-Ti-C,组织为Fe、C元素固溶强化的β-NiAl细小等轴晶加晶界上不连续分布的或晶粒内析出的(W,Ti)C。颗粒增强NiAl金属间化合物显微硬度HV467,比铸造组织显著提高。对激光合成NiAl金属间化合物的组织形成机制、成分变化及控制和强化机制进行了讨论。
The (W, Ti) C particles reinforced NiAl intermetallics were synthesized by coaxial powder feeding and Ni / Al-WC-TiC composite powders with high power CO 2 laser. The composition, phase and microstructure of the composites were analyzed by EDS, XRD and SEM. The results show that the stoichiometric ratio of the composite material is Ni-35Al-18Fe-W-Ti-C, and the microstructure is composed of Fe and C solid solution strengthening β-NiAl fine equiaxed grains with discontinuous distribution or grain boundaries Within the precipitation of (W, Ti) C. Particle reinforced NiAl intermetallic compound microhardness HV467, significantly higher than the cast structure. The formation mechanism, composition variation and control and strengthening mechanism of laser-synthesized NiAl intermetallics were discussed.