Microstructure and wear behavior of Mo–60Si–5B coating doped with 0.5 ​at% La by spark plasma sintering

Mo–60Si–5B coating doped with 0.5 ​at% La was prepared on niobium silicon based alloy by spark plasma sintering. The microstructure and wear behavior of the 0.5La–Mo–60Si–5B (0.5La-MSB) coating were investigated. The results show that the mean grain sizes of the Mo–60Si–5B (0La-MSB) and 0.5La-MSB coatings are calculated to be 3.27 ​μm and 2.85 ​μm, respectively. The addition of La plays a role of refining the grains of 0.5La-MSB coating. The specific wear rate of 0.5La-MSB coating is decreased by up to 26.8% at the oscillation frequency of 20 ​Hz and the sliding load of 11 ​N compared to 0La-MSB coating. The anti-friction performance of Mo–60Si–5B coating is modified by the addition of 0.5 ​at.% La. The improvement of anti-friction performance of the Mo–60Si–5B coating is due to the increased hardness and the provided lubrication function by La2O3. [Display omitted] •Mo–60Si–5B coating doped with 0.5 ​at% La was deposited on Nb–Si based alloy by spark plasma sintering.•The La2O3 is observed on the grain boundary of 0.5La-MSB coating and refines the grains of 0.5La-MSB coating.•The wear resistance of Mo–60Si–5B coating is modified by the addition of 0.5 ​at.% La.•The improvement in wear resistance of the coating is attributed to the increased hardness of the alloy and the provided lubrication function by La2O3.