Temperature Field Of Laser Cladding Research Articles

Temperature Field Simulation and Experimental Confirmation of Laser Cladding High-Entropy Alloy Coating on Cr12MoV

In order to meet the mechanical property of the die steel, this study used laser cladding to prepare a high-entropy alloy coating on Cr12MoV. A finite element method using a double ellipsoidal heat source model is proposed to simulate the evolution of the temperature field in laser cladding. The simulation results showed that with the increase in the power, the peak temperature of the molten pool increased from 2005.5 °C to 2357.4 °C, and the depth of the molten pool increased from 1.60 mm to 2.04 mm. The coating with the laser power of 1600 W had a good macroscopic quality and high lattice distortion (2.43 × 10−2). Due to the increase in laser energy density, the size of equiaxed crystals gradually increased from 1400 W to 1700 W. Under the comprehensive effect of the solution and fine grain strengthening, the coating with the power of 1600 W had a higher average microhardness (600 HV), which is 150% higher than that of the substrate. The experiment results further confirmed the accuracy of the simulation.

Influences of Temperature Field on Microstructural Characteristics of Laser Cladding Al2O3-13wt.%TiO2 Coating Prepared by Plasma Spraying

To explore effects of temperature field in laser cladding on structure of ceramic coating prepared by plasma spraying, a finite element model of continuous moving three-dimensional temperature field of laser cladded Al2O3-13wt.%TiO2 coating prepared by plasma spraying was constructed by the parametric design language of ANSYS finite element software to analyze temperature field during laser cladding. According to analysis results, it is very difficult to realize complete remelting of the whole preset ceramic coating during laser cladding when it is thick, which is related with the relatively low thermal conductivity of the ceramic materials. The whole coating can be divided into remelting zone, sintering zone and residual plasma spraying zone according to temperature field distribution in the zone of cladding. Given the optimal technological parameters, relatively thick remelting zone and sintering zone could be gained under the relatively low laser cladding power and relatively low scanning speed. Experimental results demonstrated that the ceramic coating after cladding formed remelting zone with small-sized and dense isometric crystals, sintering zone and lamellar residual plasma spraying zone. Moreover, the calculated results of thickness of the remelting zone and sintering zone conformed well to experimental values. This proved that the constructed finite element model is accurate and reliable.

Investigation on the columnar-to-equiaxed transition during laser cladding of IN718 alloy

In the laser cladding process of IN718 alloy, the growth of microstructure has a great impact on the performance of the alloy material. The study on the columnar-to-equiaxed transition (CET) of IN718 can further understand the formation conditions of the microstructure and control the growth of the microstructure. In this work, the columnar-to-equiaxed transition in the laser cladding process of IN718 was calculated using the Macro-Micro-Coupled Model, establishing the finite element model(FEM) for the macroscopic temperature field of laser cladding and simulating the growth of IN718 alloy microstructure by the cellular automata (CA) method (CA-FEM). It shows that CET will be delayed by increasing laser power, reducing scanning speed, or reducing preheating temperature. Increasing the laser power, reducing the scanning speed, or increasing the preheating temperature will increase the primary dendrite spacing (PDS). Reducing the laser power, increasing the scanning speed, or reducing the preheating temperature will increase the volume fraction of columnar crystals. The height of columnar crystal growth can be determined to be about 220−300μm, the volume fraction of columnar crystals is about 17 %–23 %. The maximum error of simulation is 6.72 %, and the minimum error is 1.69 %.

Effect of scanning path on temperature field in laser cladding

Temperature field of planar laser cladding with length direction, width direction and helical scanning path were simulated and analysed. Temperature distribution could be effected significantly by the laser scanning path. For short-path scanning, heat was concentrated in the local area, resulting in larger (/smaller) temperature gradient in the length (/width) direction of the substrate. However, such characteristics of long-path scanning were on the contrary. By comparison, the heat affected zone (HAZ) of the substrate with helical scanning mode was the smallest and its temperature fluctuations were more dispersed.

Finite element analysis of the temperature field in laser cladding of Ni-based powders on teeth surfaces of the helical gear

The temperature field formed in the process of laser cladding of worn teeth surfaces of the gear shaft is simulated by the finite element analysis software. Isothermal lines inside the tooth are obtained. Simulated results are compared with experimental data. Recommendations are given on improvement of the cladding technology to provide a durable continuous coating.

Finite Element Analysis of the Temperature Field in Laser Cladding of Ni-Based Powders on Teeth Surfaces of the Helical Gear

Finite Element Analysis of the Temperature Field in Laser Cladding of Ni-Based Powders on Teeth Surfaces of the Helical Gear

A FEM model for simulating temperature field in coaxial laser cladding of TI6AL4V alloy using an inverse modeling approach

In this paper, a 3D thermal finite element (FE) model is built for the simulation of temperature field in the laser cladding of Ti6Al4V (TC4) alloy. Instead of directly acquiring the geometric parameters of cladding layer and heat source for a concrete FE simulation through the measured data in experiments, this model is able to achieve temperature distributions for laser cladding with varying combinations of process parameters by constructing an adaptive cladding layer and moving heat source model using an inverse modeling approach. First, correlation experiments of single-track laser cladding TC4 powder on TC4 substrate were carried out based on central composite design (CCD) with the cladding parameters, laser power (400–600W), scanning speed (500–700mm/min) and powder feed rate (30–60rev/min). Then the relationships between process parameters and the geometries of cladding layer as well as the radius of spherical heat source are derived via regression analysis as an inverse manner. In addition, the spherical heat source is originally employed in the FE thermal simulation of coaxial laser cladding process. Detailed 3D transient thermal analyses have been performed with temperature-dependent material properties and the calibration of heat source is also provided. The proposed model is validated by the numerical and experimental results. It is found that it has potential to be applied in the thermal simulation of laser cladding with varying process parameters, considering the variation of the characteristic dimensions of deposition bead and the heat source.

激光熔覆数值模拟的应用及发展

文中介绍了国内外数值模拟技术在激光熔覆温度场研究中的应用情况；对影响数值模拟的几个主要因素进行了分析，指出了数值模拟技术在激光熔覆温度场应用中存在的问题，并在此基础上提出了未来的发展方向。 The application of domestic and overseas numerical simulation technology in the study of temperature field of laser cladding was described in this paper. Several main factors that affect the numerical simulation were analyzed. The problems of the application of numerical simulation in temperature field of laser cladding were pointed out and the important development direction was presented on this basis.

Effects of Process Variables on Temperature Field of Laser Cladding

Laser cladding utilizes a laser as energy source to apply a layer of a desired material onto a substrate. As a complex thermal-mechanical process, laser cladding is not quite understood yet. In this paper, effects of process variables on temperature variation during laser cladding are investigated with finite element method. The powder feeding during cladding is taken into account by using the element’s functions of “death” and “birth”. This makes the analysis more accurately. The analysis results show that the maximum temperature at the melting pool during cladding is directly proportional to the laser power and preheated temperature. The maximum cooling rate at the melting pool is inversely proportional to them. Increasing the preheated temperature can decrease the cooling rate of the clayed layer effectively. Increasing the laser power can also decrease the cooling rate, but the effect is not obvious.

The Numerical Simulation on the Temperature Field of Laser Cladding

This article uses the finite element software ABAQUS in the process of laser cladding to form the numerical simulation, which establishes numerical simulation model of the temperature field of laser cladding forming the heat transfer. The results show that the laser scanning position of the cladding layer depth direction of a high temperature gradient. Simulation of temperature changes of a known point the temperature change in laser scanning region is drastic. The experimental results show that the numerical simulation model of the temperature field is reasonable. Therefore, the numerical simulation model can be used to analyze the influence of the laser cladding parameters on the temperature field and simulate remelting depth under any scanning speed.

斜齿轮轴齿面激光熔覆过程中温度场的数值分析

斜齿轮轴齿面激光熔覆过程中温度场的数值分析

斜齿轮轴齿面激光熔覆过程中温度场的数值分析

斜齿轮轴齿面激光熔覆过程中温度场的数值分析

斜齿轮轴齿面激光熔覆过程中温度场的数值分析

斜齿轮轴齿面激光熔覆过程中温度场的数值分析

Numerical Analysis of Temperature Field in Laser Cladding on Teeth Surfaces of Gear Shaft

Temperature field of laser cladding on teeth surfaces of gear shaft was numerical simulated with finite element analysis software – ANSYS. The simulation result show that the heat caused by laser beam is concentrated inside the tooth mostly. An effect of preheating in the adjacent tooth is also brought about by injected laser energy. In order to make use of the effect of preheating and avoid the concentration of heat, all of the corresponding flanks of teeth should be cladded first and the other flanks of teeth be cladded secondly in the process of laser cladding. It is also shown that the problems of excessive melted down and collapsing of tooth-tip would be easily resulted in by the heat that concentrated in tooth-tip if the tooth-side and tooth-tip be cladded at the same time. The results of analysis and experiment show that at least two times of scanning should be executed in the process of laser cladding on teeth surfaces. At the first scanning, dimension of laser beam should be reduced properly. And the tooth-tip should not be irradiated directly by laser beam. After the first scanning, the gear should be circumrotated a certain angle. And the included angles between the two sides of tooth-tip and horizontal plane should be approximately equal. Then the second scanning could be prosecuted at the tooth-tip. Experiment results show that continuous and compact cladding coat could be gained by this craft. It is proved that this technological craft is reasonable and effective.