Numerical simulation on temperature field in multi-layers inside-beam powder feeding when laser cladding

作者：Wang M D^*; Shi S H; Liu X B; Song C F; Sun L N

来源：Key Engineering Materials, 2012, 499: 114-119.

DOI：10.4028/www.scientific.net/KEM.499.114

• Actual temperature
• Bath temperatures
• Cladding layer
• Cooling rates
• Defocus distance
• Finite element models
• Gaussian lasers
• Heat sources
• High temperature
• Highest temperature
• Initial conditions
• Laser scanning speed
• Layer by layer
• Low temperatures
• Manufacturing process
• Melt layer
• Point heat source
• Powder feed rate
• Powder feeding
• Research topics
• Surface temperatures
• Temperature Field
• Temperature gradient
• Thickness direction

Numerical simulation of laser cladding is the main research topics for many universities and academes, but all researchers used the Gaussian laser light source. Due to using inside-beam powder feeding for laser cladding, the laser is dispersed by the cone-shaped mirror, and then be focused by the annular mirror, the laser can be assumed as the light source of uniform intensity.In this paper,the temperature of powder during landing selected as the initial conditions, and adopting the life-and-death unit method, the moving point heat source and the uniform heat source are realized. In the thickness direction, using the small melt layer stacking method, a finite element model has been established, and layer unit is acted layer by layer, then a virtual reality laser cladding manufacturing process is simulated. Calculated results show that the surface temperature of the cladding layer depends on the laser scanning speed, powder feed rate, defocus distance. As cladding layers increases, due to the heat conduction into the base too late, bath temperature will gradually increase. The highest temperature is not at the laser beam, but at the later point of the laser beam. In the cladding process, the temperature cooling rate of the cladding layer in high temperature section is great, and in the low-temperature, cooling rate is relatively small. These conclusions are also similar with the normal laser cladding. Finally, some experiments validate the simulation results. The trends of simulating temperature are fit to the actual temperature, and the temperature gradient can also explain the actual shape of cross-section. ? (2012) Trans Tech Publications, Switzerland.

• 出版日期2012