Effect of Al Addition on Properties of FeB-Ni Hard Materials

FeB-Ni hard materials demonstrate high hardness, excellent wear resistance and cost-effectiveness, establishing them as promising candidates for novel hard materials. To enhance its application as cutting materials, it is crucial to further improve its hardness and fracture toughness. In this study, the performance of FeB-10Ni hard materials were enhanced through the addition of Al. The alterations in the microstructure and phase composition of the sintered compacts with varying Al contents were analyzed. Additionally, the hardness, fracture toughness and density of the sintered compacts were evaluated. FeB-10Ni-Al hard materials were prepared by ball milling and spark plasma sintering (SPS). The powder compositions exhibit Al contents varying from 1 to 10 vol.%. The results showed that FeB-10Ni-Al hard materials with different Al contents were successfully synthesized under the following conditions: ball milling for 21.6 ks, sintering at 1373 K, holding for 0.9 ks, and applying a pressure of 50 MPa. With the Al contents increased, newly NiAl phase emerged in the sintered compacts, significantly enhancing both hardness and fracture toughness. In general, compared with FeB-10Ni hard materials, the hardness and fracture toughness of FeB-10Ni-4Al increased by approximately 33% and 64% respectively, while its relative density improved by about 3%.