The Effect of N/O Elements on the Microstructure and Mechanical Properties of Ti-N-O Alloys

A novel Ti-N-O composite was prepared by powder nitriding/ oxynitriding combined with Spark-plasma Sintering（SPS）method. The effects of N/O on the microstructure and mechanical properties of Ti-N-O alloy were systematically studied. The results showed that the addition of N/O elements significantly improved the yield strength and the hardness of commercially pure titanium(cp-Ti). And the O element played a leading role in regulating the microstructure and morphology of Ti-N-O alloy. With the addition of O element, the microstructure showed equiaxed structure, and the characterization showed that this region is O-enriched region, and a small amount of nano-TiO2 particles appeared in the alloy, which together led to the change of the microstructure. At the same time, more large-angle grain boundaries were generated in the Ti-N-O alloy.