Boron Influence on Structures and Properties in Nickel-Based Alloys

Abstract

Nickel-base alloys with different boron contents were prepared by vacuum arc furnace. The effect of the boron contents to metallography was characterized simultaneously by XRD and SEM with EDS part. The thermal behavior was analyzed by DSC curves which mainly represents the eutectic temperature of alloys. The Vickers hardness and ball-on-flat wear test were carried out to reveal the relationship between metallographic phase formation and wear resistance. The results indicated that main composites are eutectic Ni-Cr as matrix and CrB, Ni3B as precipitated phase. A considerable amount of dislocation and stacking faults exist in the specific orientation (200) of Ni3B. 2.0~4.0%B alloys melt at 1060oC, while the boride-poor alloy melts at 1085oC. 3.0~4.0%B alloys performed the best on wear resistance. Wear volume reduces along with increasing hardness at the beginning, and then keeps invariant. Borides are main reinforcing phases, which affects hardness and wear resistance greatly.