Diamond wire sawing is widely used in processing NdFeB rare earth permanent magnets. However, it induces periodic saw marks and fracture chipping pits, which severely affect the flatness and surface quality of the products. In this study, the lateral motion of the diamond wire was monitored to determine the surface formation mechanism. Then, a white light interferometer and an SEM were used to observe the sawed surface profile. Finally, the surface quality was quantitatively studied by identifying the area rate of fracture chipping pits with an image recognition MATLAB script. According to the observation results, the calculation formula of PV which is related to the process parameters was deduced. Additionally, by combining the fracture rate and wire vibration, a novel method was proposed to investigate the optimal process parameters. It can be found that the surface quality sawed at P = 0.21 MPa, v_f = 0.2 mm/min, and v_s = 1.8 m/s remains better than when sawed at P = 0.15 MPa, v_f = 0.1 mm/min, and v_s = 1.8 m/s, which means the sawing efficiency can be doubled under such circumstances, i.e., when the surface quality remains the same.

AlSi10Mg has a good forming ability and has been widely accepted as an optimal material for selective laser melting (SLM). However, the strength and elongation of unmodified AlSi10Mg are insufficient, which limits its application in the space industry. In this paper, yttrium oxide (Y₂O₃) nanoparticles modified AlSi10Mg composites that were manufactured using SLM. The effects of Y₂O₃ nanoparticles (0~2 wt.% addition) on the microstructure and mechanical properties of AlSi10Mg alloys were investigated. An ultimate tensile strength of 500.3 MPa, a yield strength of 322.3 MPa, an elongation of 9.7%, a good friction coefficient of 0.43, and a wear rate of (3.40 ± 0.09) ×10⁻⁴ mm³·N⁻¹·m⁻¹ were obtained with the addition of 0.5 wt.% Y₂O₃ nanoparticles, and all these parameters were higher than those of the SLMed AlSi10Mg alloy. The microhardness of the composite with 1.0 wt.% Y₂O₃ reached 145.6 HV_0.1, which is an increase of approximately 22% compared to the unreinforced AlSi10Mg. The improvement of tensile properties can mainly be attributed to Orowan strengthening, fine grain strengthening, and load-bearing strengthening. The results show that adding an appropriate amount of Y₂O₃ nanoparticles can significantly improve the properties of the SLMed AlSi10Mg alloy.