Research on Temperature in Floated Powder Bed Fusion Laser Additive Manufacturing Process
In laser powder bed additive manufacturing technology,due to the high power density of the laser and the low thermal conductivity of the powder bed,residual stresses caused by rapid alternating temperature gradients exist in the formed parts produced.The use of floated powder bed technology,which replaces the underlying powder with molten tin,can achieve the effect of reducing the stress of the formed part and refining the grain size.Under the condition of simplifying the melt pool by considering temperature related physical parameters,a transient mesoscopic model is established for the case of floated powder bed,and compared with the case of traditional powder bed.The results indicate that floated powder bed can reduce the temperature gradient and accelerate the cooling rate by about 10%.A grain with an average size of 5 μm was found in the microstructure of liquid floated powder bed formed parts,which is significantly smaller than the microstructure obtained by traditional LPBF technology,verifying the cooling rate calculation results.
floated powder bed fusiontemperature gradientcooling speednumerical simulation
万方数据
维普
