Tribological study on a novel wear-resistant AlMgB₁₄-Si composite

AlMgB₁₄ based composites are promising candidates for use as cutting tool etc. In this respect, tribological behavior is one of the most important performances among all the criteria. In this work, a novel AlMgB₁₄-30 wt% Si composite (referred to as BMAS30) was prepared by Spark Plasma Sintering. and its tribological property was investigated under different counterface materials (316 L and Si₃N₄) and loads in ambient environment. Besides, the fracture toughness and the hardness were measured. We found that BMAS30 has a good fracture toughness of 5.90 MPa m^1/2 and a super-high hardness of 27 GPa. In terms of the tribological properties, BMAS30 shows good tribological properties when sliding against 316 L, i.e., a lower friction coefficient of 0.19–0.28 and wear rate of 7.00–8.00 × 10⁻⁶ mm³/N m, while it presents a relatively high friction coefficient of 0.35–0.46 and wear rate of 3.80–9.00 × 10⁻⁵ mm³/N m when sliding against Si₃N₄. In the former case, large numbers of Si grains pull-out pits formed on the worn surface that can store wear debris, which is conducive to lower the friction and wear; the latter produces severe fatigue fracture under high Hertz contact stress and thereby aggravates the friction and wear.