Campanelli Sabina Luisa, Contuzzi Nicola, Posa Paolo, Angelastro Andrea
Department of Mechanics, Mathematics and Management, Politecnico di Bari, Viale Japigia 182, 70126 Bari, Italy.
Materials (Basel). 2019 Jul 27;12(15):2397. doi: 10.3390/ma12152397.
The selective laser melting process is a growing technology for the manufacture of parts with very complex geometry. However, not all materials are suitable for this process, involving rapid localized melting and solidification. Tungsten has difficulties due to the high melting temperature. This study focuses on the possibility of processing a WC/Co/Cr composite powder using selective laser melting. Samples were fabricated and characterized in terms of density, defects, microstructure and hardness. Tests were conducted with hatch spacing of 120 μm and process speed of 40 mm/s. A constant laser power of 100 W and a powder layer thickness of 30 μm were used. A relative density of 97.53%, and therefore a low porosity, was obtained at an energy density of 12.5 J/mm. Microscopic examination revealed the presence of small cracks and a very heterogeneous distribution of the grain size.
选择性激光熔化工艺是一种用于制造具有非常复杂几何形状零件的不断发展的技术。然而，并非所有材料都适用于此工艺，因为该工艺涉及快速的局部熔化和凝固。由于钨的熔点高，所以加工钨存在困难。本研究聚焦于使用选择性激光熔化工艺加工WC/Co/Cr复合粉末的可能性。制备了样品，并对其密度、缺陷、微观结构和硬度进行了表征。测试时的扫描间距为120μm，加工速度为40mm/s。使用的激光功率恒定为100W，粉末层厚度为30μm。在能量密度为12.5J/mm时，获得了97.53%的相对密度，因此孔隙率较低。微观检查发现存在小裂纹，且晶粒尺寸分布非常不均匀。
