Simulation and Study of Manufacturing of W–Cu Functionally Graded Materials by a Selective Laser Melting Process

Plasma-facing components (PFCs) were simulated by ANSYS, and the influence of gradient layer number and composition distribution index on the distribution of temperature field and stress field was analyzed. The simulation results show that a gradient structure with four gradient layers and a component distribution index of 1 makes the PFC assembly have lower overall temperature and lower thermal stress. Tungsten–copper functionally graded materials (W–Cu FGMs) (W-20 vol% Cu/W-40 vol% Cu/W-60 vol% Cu/W-80 vol% Cu) were fabricated by a selective laser melting (SLM) process based on finite element simulation results. The effects of microstructure on the hardness, internal stresses, thermal conductivity, and thermal expansion coefficient of the W–Cu FGMs were evaluated. The results show that hardness increases from 196 to 1173 HV0.3 with increasing W content. The internal stresses of W-20 vol% Cu, W-40 vol% Cu, W-60 vol% Cu, and W-80 vol% Cu are about 191.7 MPa, 627 MPa, 1049.5 MPa, and 561.9 MPa, respectively. The thermal conductivity of the W–Cu FGM is 23 W/m·K and the thermal diffusion coefficient is 10 mm2/s at 25 °C, and the thermal conductivity rises to 70 W/m·K and the thermal diffusion coefficient rises to 18.5 mm2/s at 800 °C. After 100 thermal shock cycles, the internal defects increased, but the interface between the gradient layers remained well bonded.