Numerical Simulation of the Temperature Field in Multi-Layer Powder-Feeding Laser Cladding Forming

Abstract

The numerically simulation of temperature field was carried out by the ANSYS software in multi-layer powder-feeding laser cladding forming.3-D finite element model was found, which nonlinear characteristics of the material thermal properties and the boundary conditions of the convective transfer heat was considered; The process of powder falling into the substrate and cladding element growing was accomplished by “Element Birth and Death technology” in the process of numerical simulation. The result shown that the primarily solidified cladding layer to the following cladding layer has a preheating function in the process of multi-layer laser cladding forming, the initial temperature of following cladding layer is higher than primarily melted cladding layer; The thermal cycling curves of the molten pool nodes takes on periodic variation and basic similar in every layer cladding; The end effect problem is apt to happen in cladding layer, which the phenomenon of edge collapsing or partially burnt is formed; The temperature gradient distribution is divided into two parts, the temperature gradient level distribution along the laser scanning direction in the top and perpendicular distribution in the bottom, The temperature gradient appearances mutation and maximum value in the junction of the substrate and cladding layer, which the crack is apt to be caused in this region.

Effect of Defocus Distance on Layer Quality in Insider-Laser Coaxial Powder Feeding Laser Cladding

“…This paper studies the effect of defocus distance on layer quality, in order to avoid the overlap rate's influence on the surface flatness, we need to choose the appropriate overlap rate. The overlap rate directly influences the surface flatness, which we can calculate with correlational equations [4,5]. The equations about center distance c and the critical overlap rate ηc are listed.…”

“…The present researches mainly aim at laterally powder feeding laser cladding, with the purpose of researching the influence of processing parameters on the cladding layer's width and height, such as powder feeding velocity, laser power, scanning velocity, shielding gas flow and so on. Moreover, some experts has researched the effect of overlap rate on the layer quality [3][4][5].…”

Numerical Simulation and Experimental Study on Residual Stress in the Curved Surface Forming of 12CrNi2 Alloy Steel by Laser Melting Deposition

“…Secondly, we use the self-defined heat source subroutine to load and set the initial ambient temperature at 25 °C. Finally, we create a job to solve [ 35 , 36 , 37 , 38 ].…”

“…At the same time, heat transfer by convection and radiation is achieved by setting the convection and radiation boundary conditions, and the undeposited area is temporarily suppressed using the model change function. Secondly, we use the self-defined heat source subroutine to load and set the initial ambient temperature at 25 • C. Finally, we create a job to solve [35][36][37][38].…”