Numerical simulation of heat transfer and fluid flow in coaxial laser cladding process for direct metal deposition

Abstract

Articles you may be interested inThe coaxial laser cladding process is the heart of direct metal deposition ͑DMD͒. Rapid materials processing, such as DMD, is steadily becoming a tool for synthesis of materials, as well as rapid manufacturing. Mathematical models to develop the fundamental understanding of the physical phenomena associated with the coaxial laser cladding process are essential to further develop the science base. A three-dimensional transient model was developed for a coaxial powder injection laser cladding process. Physical phenomena including heat transfer, melting and solidification phase changes, mass addition, and fluid flow in the melt pool, were modeled in a self-consistent manner. Interactions between the laser beam and the coaxial powder flow, including the attenuation of beam intensity and temperature rise of powder particles before reaching the melt pool were modeled with a simple heat balance equation. The level-set method was implemented to track the free surface movement of the melt pool, in a continuous laser cladding process. The governing equations were discretized using the finite volume approach. Temperature and fluid velocity were solved for in a coupled manner. Simulation results such as the melt pool width and length, and the height of solidified cladding track were compared with experimental results and found to be reasonably matched.

Flow characteristics of metallic powder grains for additive manufacturing

“…Thus, the powder interacts strongly with the the fluid dynamics of the shielding gas, that effects crucially the trajectory of single powder particles and hence, its location of deposition. Numerical approaches developed by He et al [2], Peyre et al [3], Wen et al [4] and Qi et al [5] describe the fusion process, however, neglect the transport of powder between nozzles and substrate. Therefore, the objective of the current contribution is to describe numerically the complex process of powder deposition on a substrate.…”

Solute transport and composition profile during direct metal deposition with coaxial powder injection

“…The interaction between laser and powder, including the powder temperature and attenuation of laser power due to powder addition, has been investigated in previous work [1,2]. Only results of solute transport and composition profile are presented here.…”

“…The concentration of carbon and chromium is taken as 0.4 wt% and 5 wt% in H13 powder, and 0.1 wt% and 0.5 wt% in low carbon steel substrate, respectively. The data used for calculations [2,36] are presented in Table 2. The processing parameters used in the whole paper is as follows: laser power: 1900 W; beam Table 2 Data used for calculations.…”

“…Attenuation of laser power during interaction between a laser and powder was investigated a lot [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Qi et al [2] considered the coaxial laser powder interaction while modelling heat transfer and fluid flow during DMD. A semiempirical method of evaluating the laser energy redistribution during CO 2 laser cladding with lateral powder injection was reported by Gedda et al [5].…”

Temperature and composition profile during double-track laser cladding of H13 tool steel

“…Because of demanding longer computer run-time and bigger data storage space for multi-track laser cladding, most numerical models for laser cladding focused on single-track laser processing [1][2][3][4][5][6][7][8][9][10][11]. However, with the rapid development of multi-track laser processing, a deeper understanding of temperature field and its effects on the thermo-physical properties of materials is more pressing.…”