Steel matrix composites (SMCs) reinforced with WC particles were fabricated via selective laser melting (SLM) by employing various laser scan strategies. A detailed relationship between the SLM strategies, defect formation, microstructural evolution, and mechanical properties of SMCs was established. The laser scan strategies can be manipulated to deliberately alter the thermal history of SMC during SLM processing. Particularly, the involved thermal cycling, which encompassed multiple layers, strongly affected the processing quality of SMCs. S-shaped scan sequence combined with interlayer offset and orthogonal stagger mode can effectively eliminate the metallurgical defects and retained austenite within the produced SMCs. However, due to large thermal stress, microcracks that were perpendicular to the building direction formed within the SMCs. By employing the checkerboard filling (CBF) hatching mode, the thermal stress arising during SLM can be significantly reduced, thus preventing the evolution of interlayer microcracks. The compressive properties of fabricated SMCs can be tailored at a high compressive strength (∼3031.5 MPa) and fracture strain (∼24.8%) by adopting the CBF hatching mode combined with the optimized scan sequence and stagger mode. This study demonstrates great feasibility in tuning the mechanical properties of SLM-fabricated SMCs without varying the set energy input, e.g., laser power and scanning speed.

通过采用各种激光扫描策略，通过选择性激光熔化（SLM）来制造用WC颗粒增强的钢基复合材料（SMC）。建立了SLM策略，缺陷形成，微结构演变和SMC力学性能之间的详细关系。可以控制激光扫描策略，以在SLM处理期间故意更改SMC的热历史。特别是，涉及多层的热循环强烈影响了SMC的加工质量。S形扫描序列结合层间偏移和正交交错模式可以有效消除生产的SMC中的冶金缺陷和残留的奥氏体。但是，由于较大的热应力，在SMC中形成了垂直于建筑方向的微裂纹。通过采用棋盘格填充（CBF）阴影线模式，可以显着降低SLM期间产生的热应力，从而防止了层间微裂纹的发展。通过采用CBF阴影线模式与优化的扫描顺序和交错模式相结合，可以在高抗压强度（约3031.5 MPa）和断裂应变（约24.8％）的情况下调整制造的SMC的压缩性能。这项研究表明，在不改变设定能量输入（例如激光功率和扫描速度）的情况下，调整SLM制造的SMC的机械性能具有很大的可行性。通过采用CBF阴影线模式与优化的扫描顺序和交错模式相结合，可以在高抗压强度（约3031.5 MPa）和断裂应变（约24.8％）的情况下调整制造的SMC的压缩性能。这项研究表明，在不改变设定能量输入（例如激光功率和扫描速度）的情况下，调整SLM制造的SMC的机械性能具有很大的可行性。通过采用CBF阴影线模式与优化的扫描顺序和交错模式相结合，可以在高抗压强度（约3031.5 MPa）和断裂应变（约24.8％）的情况下调整制造的SMC的压缩性能。这项研究表明，在不改变设定能量输入（例如激光功率和扫描速度）的情况下，调整SLM制造的SMC的机械性能具有很大的可行性。