Effect of pores on the performance of diamond grinding wheels fabricated by laser additive manufacturing

Abstract

When using laser additive manufacturing to fabricate multi-layer abrasive diamond wheels, the pores within the abrasive segments are favorable factors for grinding performance, which should be reasonably designed and utilized. In this paper, laser additive technology is employed to fabricate grinding wheel abrasive segments. The pore characteristics of these segments are examined and quantitatively analyzed, followed by tests on their mechanical and grinding properties. Ultimately, the study explores and elucidates the relationship between pore characteristics and the mechanical and wear properties of the abrasive segments. Based on these findings, optimization recommendations for the pore structure of the grinding wheels are provided. The results indicate that the porosity of the fabricated abrasive segments ranges from 18 % to 27 %, with the pore equivalent diameter predominantly between 500 μm and 700 μm. The pore shapes are primarily rod and discoid, and the sphericity of the pores is mainly distributed between 0.3 and 0.65. When the porosity is less than 24.4 %, the abrasive segments exhibit higher elastic modulus and tensile strength. As the pore minimum equivalent diameter increases, the elastic modulus decreases. Conversely, an increase in the proportion of spherical pores contributes to an enhancement in tensile strength. Higher porosity, larger pore dimensions, and a greater proportion of spherical pores lead to increased wear and fragmentation of the diamonds, worsening wear morphology, and elevated temperatures during the grinding process. Consequently, it is recommended that the design of pore structures incorporate a balance of moderate porosity, smaller pore sizes, and a variety of pore shapes to optimize the comprehensive performance of the abrasive segments.