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

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5196
Author(s):  
Yuan Zhang ◽  
Yexin Jin ◽  
Yao Chen ◽  
Jianfeng Liu
Keyword(s):  
Heat Source ◽  
Laser Cladding ◽  
Thermal Deformation ◽  
Equivalent Stress ◽  
Machining Process ◽  
Powder Flow ◽  
Water Cooling ◽  
Melting Pool ◽  
Thermal Dilation ◽  
Powder Feeding

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 on Temperature Field in Multi-Layers Inside-Beam Powder Feeding when Laser Cladding

2012 ◽  
Vol 499 ◽  
pp. 114-119 ◽  
Author(s):  
Ming Di Wang ◽  
Shi Hong Shi ◽  
X.B. Liu ◽  
Cheng Fa Song ◽  
Li Ning Sun
Keyword(s):  
Numerical Simulation ◽  
Heat Source ◽  
Laser Beam ◽  
Cooling Rate ◽  
Light Source ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Initial Conditions ◽  
Cladding Layer ◽  
Powder Feeding

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 manu-facturing 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 clad-ding 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 ex-plain the actual shape of cross-section.

Numerical simulation of gas-powder flow in laser cladding with coaxial powder feeding

2013 ◽  
Vol 25 (8) ◽  
pp. 1951-1955
Author(s):  
董敢 Dong Gan ◽  
刘继常 Liu Jichang ◽  
李媛媛 Li Yuanyuan
Keyword(s):  
Numerical Simulation ◽  
Laser Cladding ◽  
Powder Flow ◽  
Powder Feeding

scholarly journals Effect of Cooling Method on Formability of Laser Cladding IN718 Alloy

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3734
Author(s):  
Jianyu Yang ◽  
Xudong Li ◽  
Fei Li ◽  
Wenxiao Wang ◽  
Zhijie Li ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Primary Dendrite ◽  
Solidification Rate ◽  
Processing Condition ◽  
Layer By Layer ◽  
Water Cooling ◽  
Cooling Device ◽  
K Value ◽  
Cladding Layer ◽  
Thin Walled

The finite element model (FE) of temperature field of straight thin-walled samples in laser cladding IN718 was established, and the growth of microstructure was simulated by cellular automata (CA) method through macro-micro coupling (CA-FE). The effects of different cooling conditions on microstructure, hardness, and properties of laser-cladding layer were studied by designing cooling device. The results show that the simulation results are in good agreement with the microstructure of the cladding layer observed by the experiment. With the scanning strategy of reducing laser power layer-by-layer, the addition of water cooling device and the processing condition of 0.7 mm Z-axis lift, excellent thin-walled parts can be obtained. With the increase of cladding layers, the pool volume increases, the temperature value increases, the temperature gradient, cooling rate, solidification rate, K value gradually decrease, and eventually tend to be stable, in addition, the hardness shows a fluctuating downward trend. Under the processing conditions of layer-by-layer power reduction and water cooling device, the primary dendrite arm spacing reduced to about 8.3 μm, and the average hardness at the bottom of cladding layer increased from 260 HV to 288 HV. The yield strength and tensile strength of the tensile parts prepared under forced water cooling increased to a certain extent, while the elongation slightly decreased.

Parameter optimisation of laser cladding repair for an Invar alloy mould

2018 ◽  
Vol 233 (8) ◽  
pp. 1859-1871 ◽  
Author(s):  
Shichao Zhu ◽  
Wenliang Chen ◽  
Xiaohong Zhan ◽  
Liping Ding ◽  
Junjie Zhou
Keyword(s):  
Dilution Rate ◽  
Laser Cladding ◽  
Laser Power ◽  
Scanning Speed ◽  
Advanced Technology ◽  
Invar Alloy ◽  
Geometric Features ◽  
Feeding Rates ◽  
Cladding Layer ◽  
Powder Feeding

Laser cladding repair is an advanced technology for repairing Invar alloy moulds; however, the influences of various processing parameters on the quality of the Invar alloy moulds have yet to be determined. To explore the optimisation of laser cladding repair parameters, analyses of the geometric features and microstructure of the cladding layer were conducted. First, the influences of different powder feeding rates and scanning speeds on the dilution rate of the substrate were investigated by establishing a mathematical model of the laser power attenuation. Next, the influences of the parameters on the geometric features of the cladding layer were analysed. Finally, the influences of the parameters on the microstructure of the cladding layer were evaluated. At a laser power of 2300 W, a scanning speed of 3 m/min, and a powder feeding rate of 9 g/min, the best results of the width, height, dilution rate, roughness, and contact angle of the cladding layer were obtained. The results of this study indicated that excellent metallurgical bonding occurred between the cladding layer and the interface layer, and that the intended geometric features and desired microstructure of the cladding layer were obtained.

scholarly journals Comparison of Powder Feeding and Wire Feeding in Laser Cladding

2013 ◽  
Vol 31 (4) ◽  
pp. 13-16 ◽  
Author(s):  
Young-Nam Ahn ◽  
Cheolhee Kim
Keyword(s):  
Laser Cladding ◽  
Wire Feeding ◽  
Powder Feeding

scholarly journals Effect of High−Speed Powder Feeding on Microstructure and Tribological Properties of Fe−Based Coatings by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Qiang Wang ◽  
Runling Qian ◽  
Ju Yang ◽  
Wenjuan Niu ◽  
Liucheng Zhou ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
High Speed ◽  
High Efficiency ◽  
Adhesive Wear ◽  
Steel Substrate ◽  
Powder Materials ◽  
Powder Feeding

In order to improve the wear resistance of 27SiMn steel substrate, Fe−based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high−speed powder feeding (HF) process was used to prepare Fe−based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X−ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe−based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high−speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high−efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.

Optical diagnostics and optimization of the gas-powder flow in the nozzles for laser cladding

2018 ◽  
Vol 108 ◽  
pp. 310-320 ◽  
Author(s):  
K.Yu. Nagulin ◽  
F.R. Iskhakov ◽  
A.I. Shpilev ◽  
A.Kh. Gilmutdinov
Keyword(s):  
Laser Cladding ◽  
Optical Diagnostics ◽  
Powder Flow

Numerical Simulation of Temperature Field of Coaxial Powder Flow in Laser Cladding

2009 ◽  
Vol 29 (11) ◽  
pp. 3114-3120 ◽  
Author(s):  
杨洗陈 Yang Xichen ◽  
栗丽 Li Li ◽  
张烨 Zhang Ye
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Laser Cladding ◽  
Powder Flow
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