The Experimental Researchon CNC Pulse Electric Plating

With the development of electric brush plating equipment research, and the advent of new electronic pulse power, pulse electric plating technology was developed as a new process. NC pulse plating technology not only solved the problem of the limits of irregular parts geometry shape to the anode shape, but also was able to control the plating gap and parts moving speed accurately. The quality of coating was improved obviously comparing to traditional brush plating process which having low efficiency, high labor intensity and inconsistent coating quality. The traditional brush plating process due to the shape and size limits of tools and parts to anode, there will inevitably be plating or coating flaw more or less, while when the CNC technology combining with traditional electric brush plating technology and electrical plating technology, with the help of precise position and speed control function of CNC, problems which the traditional electric brush technology hard to solve can be effectively solved. Therefore, a kind of electric plating process which combining modern CNC technology with pulse electric plating technology was put forward, and related process experiments were researched.Firstly, a theoretical analysis was conducted to improve the limiting current density on the base of NC pulse plating theory; a mathematical model of the electric field between the two poles of NC pulse electric plating was built, and the finite element analysis of the built mathematical model was conducted, found that the current density distribution on the surface of the cathode with a certain locality and the current density of the cathode decreases rapidly away from the region positive to the anode tool, which provide theoretical guidance for the subsequent basis experiments.Secondly, the NC pulse plating experimental device was introduced, the related electroplating system and the anode nozzle were designed.Finally, a single factor and orthogonal experiment was conducted, the impact of the pulse voltage, the relative gap between the various factors, the duty cycle of the pulse width, pulse frequency and the relative speed of the cathode and anode on the roughness and hardness degree of coating surface, was researched, and the relevant process parameters of NC pulse plating experiments was confirmed. The final coating by orthogonal experiment to optimize the preparation of roughness value 0.152μm, maximum hardness 585.63HV, the optimal coating which was uniform coating, crystalline dense, and smooth. In order to obtain optimum coating, CNC pulse EFI Pulse plating voltage selection 21V, the relative gap control in 1mm～2mm, selected from 65% duty cycle of the pulse width, pulse frequency selection 800Hz.