Selective laser melting high-performance ZrC-reinforced tungsten composites with tailored microstructure and suppressed cracking susceptibility

• DOI: 10.1007/s42864-021-00076-8
• Publication Date: 2021-03-08T14:03:22Z
• Authors: Yan Zhou; Yu-Si Che; Chong Wang; Rui Liu; Shi-Feng Wen
• Keywords: Equiaxed crystals; Selective Laser Melting; Ductility (Earth science)

Selective laser melting (SLM) tungsten (W) constantly suffered from severe cracking phenomenon due to the high melting temperature and low intrinsic ductility of W material. To address this significant issue, active ZrC nanoparticles were introduced into the W matrix to form ZrC/W composites in situ by SLM to enhance the intrinsic toughness of W in this study. It mainly focused on the effect of ZrC nanoparticle on the microstructure and cracking behavior of SLM W. Compared to SLM W, SLM ZrC/W composites showed finer equiaxed grains rather than columnar grains, because the ZrC nanoparticles provided many heterogeneous nucleation sites. Furthermore, ZrC nanoparticles could react with oxygen impurity at the grain boundaries (GBs), and then form stable ZrO2 and ZrW2O8 to purify and improve the cohesion strength of GBs. The columnar to equiaxed transition (CET) of grains and purified GBs played an important role in inhibiting the formation and propagation of the cracks in SLM W. Therefore, SLM ZrC/W composites exhibited lower crack density and higher mechanical properties compared to SLM W. This study provides a novel approach for suppressing the cracking susceptibility of SLM W.