The Optimization Of Laser Cladding Process Parameters And Adaptive Finite Element Analysis

Recently, laser cladding technology has been the key research in advanced manufacturing technology. In order to explore the evolution of cladding layer further, in this paper, a novel method for optimizing the process parameters in laser cladding is developed based on response surface methodology (RSM). Besides, for the sake of accurate simulation of laser cladding process, which greatly makes contributions to reduce the experimental cost and time, an adaptive3-D thermal finite element (FE) model is also built to calculate the temperature distribution during the entire process of laser cladding.As is known from the empirical experiments, the process parameters of laser cladding have great effect on the geometry and dilution of clad coatings. Then, this investigation mainly focuses on the influence of laser power (400-600W), scanning speed (500-700mm/min) and powder feed rate (30-60r/min) on the shape factor and the cladding-bead geometry (layer width, layer height and molten depth) with regard to injecting Ti6A14V (TC4) powder on TC4substrate. The experimental design technique, central composite design (CCD), and RSM are used to build the mathematical model. By means of the developed model tested by analysis of variance (ANOVA) method, the relationship between process parameters and output responses and the interaction among the process parameter are analyzed and discussed in detail. The analysis results indicate that powder feed rate is the dominant factor on the width and height of cladding coating while laser scanning speed has the strongest effect on molten depth of substrate. Moreover, the validation results show that the calculated values are in good agreement with measured responses within the allowable range of cladding parameters being used. This makes it possible to acquire a good parameter combination for dilution control. Based on the results of optimization it is observed that the low level of laser power and high level of laser scanning speed can produce cladding coatings with good quality when powder feed rate is around the center value.Apart from that, the adaptive3-D thermal finite element (FE) model is also constructed that is able to achieve temperature distributions for varying combination of process parameters by constructing an adaptive moving heat source model using an inverse modeling approach during laser cladding. Correlation experiments of single-track laser cladding about injecting TC4powder on TC4substrate were carried out based on CCD with the cladding parameters. Then the relations of cladding geometries and heat source parameters with process parameters are derived via regression analysis. Detailed preprocessing techniques such as boundary conditions, material properties and the calibration of heat source are also given. The proposed model is validated by the numerical and experimental results. It is found that it has potential to be applied in varying process parameters as well as the dimensions of deposition bead and the radius of heat source.