Laser surface melting (LSM) were successfully applied in in-situ 10 vol% ZrB_2(np)/6061Al composites. Formation of nano-sized ZrB₂ phase is confirmed by FESEM, EDS and HRTEM. Due to the minimization of porosity defects, one-way laser scanning is evaluated as optimum scan route strategy. After LSM, nanoparticle aggregations in composites are largely eliminated by melt vortex and matrix grain growth pushing force. Nanoparticles are uniformly dispersed near matrix grain boundaries and agglomerations showed an explosive orientation dispersion. After LSM, the average matrix grain size decreased by 87.5% to 3.4 μm. Nanoparticle dispersion uniformity and toughness of composites are proportional to laser power density. Both strength and elongation are enhanced as the matrix grain refinement and better uniformity of the nanoparticle dispersion after LSM. When LSM for 420 NW/mm² was performed, the optimal improvements of tensile strength and elongation are 33.54% and 72.51% respectively.

激光表面熔化（LSM）成功应用于原位10体积％ZrB _2（np） / 6061Al复合材料。纳米ZrB _2的形成FESEM，EDS和HRTEM确认了该相。由于孔隙缺陷的最小化，单向激光扫描被认为是最佳的扫描路径策略。LSM之后，复合材料中的纳米颗粒聚集体会通过熔体涡流和基体晶粒生长推动力大大消除。纳米颗粒均匀地分散在基体晶界附近，并且团聚显示出爆炸性取向分散。LSM后，平均基体晶粒尺寸减少了87.5％，降至3.4μm。复合材料的纳米颗粒分散均匀性和韧性与激光功率密度成正比。LSM后，随着基体晶粒细化和纳米颗粒分散体更好的均匀性，强度和伸长率均得到增强。当LSM为420 NW / mm ^2时 进行拉伸强度和伸长率的最佳改进分别为33.54％和72.51％。