Design a New Type of Laser Cladding Nozzle and Thermal Fluid Solid Multi-Field Simulation Analysis

Abstract

Coaxial powder feeding technology in the field of metal additive manufacturing is booming. In this paper, a new laser cladding nozzle with powder feeding channels of inner and outer rings is designed. The nozzle works with a new kind of laser, which is a new heat source with an inner beam and outer beams. The water-cooling channels are simulated in Ansys Workbench. The simulation results present the temperature distribution of the working nozzle and the velocity of the cooling water. The thermal dilation of the nozzle in the working environment is also simulated. The results show that the loop water cooling channel could effectively reduce the high temperature of the nozzle down to about 200 °C. In addition, it could well restrain the thermal deformation of the nozzle lower to 0.35 mm. The equivalent stress of most parts is controlled under 360 MPa. Then, the powder flows of the inner and outer rings of the multiple powder feeding channels are simulated in Ansys Fluent. The convergence effect of the powder flow could be assumed and some significant parameters, such as the velocity, are acquired. The results present that these multiple powder feeding channels could realize the generation and removal of removable supports of workpieces with highly complex shapes and achieve a large processing range and good processing efficiency. The velocity of the powder flow at the outlet is elevated to about 5 mm/s. Then, the thermal cladding states under the new laser heat source of the powder are simulated in Workbench. The temperature of the melting process and the thermal deformation and the equivalent stress/strain of the additive parts are obtained in the emulation. The results emerge that the powder melting range and the ascending temperature of the melting pool are improved with this effect. The greatest temperature of the melting pool is about 2900 °C in the machining process, and the maximum thermal equivalent stress is 1.1407 × 1010 Pa.

Numerical Simulation and Experimental Prediction of the Cladding Layer Based on the Response Surface Method

“…High-speed steel is the base material (50 mm × 50 mm × 1 mm), Ni60 alloy is the backing cladding layer, and Ni60-WC mixed material is the second cladding layer. The birth-anddeath unit method simulates the cladding process [30][31][32], and the cladding process is A 2 → A 3 → A 1 → A 4 , as shown in Figure 1.…”

Nozzle Designs in Powder-Based Direct Laser Deposition: A Review

“…17 Powder focus spot diameters with and without passage shrinkage: a no shrinkage and b 2º shrinkage [28]. Numerical study on powder stream characteristics of coaxial laser metal deposition nozzle conducted by Zhang et al [71]. In their work, authors propose a new coaxial nozzle design and they employ numerical modelling of the process to evaluate the feasibility of that design.…”

Deep Learning-Based Cooperative Modelling of Thermal Flow and Stress Fields in Laser Powder Bed Fusion

“…While valuable perspectives on the interaction dynamics between thermal flow and stress fields have been offered by finite element methods and empirical models, these techniques exhibit discernible limitations [16,17]. Confronted with highly nonlinear, multi-scale systems, the aforementioned methods can sometimes underperform [18][19][20]. Thus, the call for a renewed methodology that aptly captures the interplay between thermal flow and stress fields has grown louder.…”