Selective laser melting of Al-Fe-V-Si heat-resistant aluminum alloy powder: modeling and experiments

摘要

A three-dimensional finite model has been proposed to simulate the temperature field in selective laser melting Al-8.5Fe-1.3V-1.7Si (wt.%) heat-resistant aluminum alloy powder. The finite element analysis was carried out using the ANSYS code, taking into account temperature-dependent material properties, the effects of the powder-to-solid transition, and the movement of laser power with a Gaussian profile. The effects of the line energy (LE) on the temperature distribution, melt pool dimensions, and cooling rates were presented in detail. The phase transformations were also discussed based on the thermal analysis. The results show that the maximum temperature in powder layer increases with the applied LE. The predicted dimensions of the melt pool are in sizes of several tens of micrometers and increase with the LE. The predicted cooling rates across the melt pool decrease with increase of the LE and decline from the center to the edge of the pool. Under the optimized LEs of 1.2 and 1.6 J/mm, sound metallurgical bonding with less building defects between adjacent tracks and layers can be obtained; the cooling rates across the melt pool exceed 10(5) A degrees C/s above the solidus temperature, which lead the formation of novel alpha-Al and A1(12)(Fe, V)3Si phases. This phase composition is predicted to keep consistent during multiple tracks and layer melting. The simulation results were compared with those acquired via experiments, and a good agreement can be found.