The Study Of Monitoring And Controlling Dimensions Of Deposition Layers In The Laser Rapid Forming Process

Laser rapid forming (LRF) has been investigated since 1990's. By far, many equipments and materials of LRF have been developed, and LRF also began to be used in the aeronautics and astronautics fields. In order to control the surface quality and dimensions precision of LRF parts, real-time monitoring and closed-loop controlling system should be built up, which result in that it is important to obtain the relationship between processing parameters and dimensions characteristic. In present work, stepwise linearity regression model has been built up by using Orthogonal regression design (ORD) method, the most effective factors of processing parameters on the dimensions of deposition layers and the approximate relations between them have been obtained, respectively. The main results are as follows:1 The influences of processing parameters on the dimensions of deposition layers have been obtained. Energy density and power density have been introduced, and the relations between dimensions of deposition layer and these two physical quantities have been studied, respectively. The following results are achieved: the influence of scanning speed on the height and width of deposition layer is remarkable, even more notable than laser power. Therefore, scanning speed is the most important adjustable factor in the process of LRF.2 Combining the advantages of orthogonal test and regressing analysis, orthogonal regression experiments have been designed. The results have been analyzed by Statistical Product and Service Solutions (SPSS). Then stepwise linearity regression model was obtained. Powder feeding rate and scanning speed are the most effective factors on the height of deposition layers. Spot diameter, scanning speed and interaction between laser power and spot diameter are the most effective factors on the width of deposition layers. The approximate relations between them are obtained, respectively.