Study On Repairing Connecting Rod With Nano-composite Brush Plating Technique Process

Remanufacture engineering is the general designation of all techniques and activities for repairing and reusing worn machine parts, which can boost machine’s performance, save energy and material, cut cost and protect the environment based on product whole life cycle and advanced technology. Developing the industry of remanufacturing is an inevitable choice to build a environment friendly harmonious society, is also an important technological approaches to develop in sustainable way.With the number of cars owed rise rapidly, cars has brought great convenience to us, but also bought challenge to energy and material using. It is now a big problem to handle the obsolete cars and other engineering goods. The engines which are scrapped still have great value. The cylinder block, crankshaft. Connecting rod, for example, can all be recycled. The connecting rod is one of the key parts of the engines with large quantity which can be remanufactured. The remanufacturing of connecting rod has great theoretical meaning and instructive significance.There are mainly two methods to remanufacture connecting rods. One is the cutting material method; the other is nano-composite brush plating method. Nano-composite brush plating method has good interchangeability and less effect on the life of connecting rod. This paper has done some study on repairing connecting rod of WD615engine with nano-composite brush plating technique process.According the requirement of remanufacturing connecting rod, the process flow of nano-composite brush plating is made. The orthogonal test of four factors at three different levels is designed to analyze the effect of the content of nano-particles in the electrolyte N, the diameter of nano-particles d, temperature of the electrolyte6, the brush plating voltage U on Coating Performance. The surface morphology, micro vikers hardness, friction and wear properties, surface residual stresses and bond strength of the coating are tested by Optical Microscopy, micro hardness tester, friction and wear spectrometer, X stress tester separately.By contrast the coating’s performance data of nano-composite coating and pure nickel coating, it can be know that the adding of nanoparticle into the coating can refining coating’s surface morphology, improve the residual stress of the coating. The hardness and friction-wear properties of the coating are also improved. Analyzing the data obtained by orthogonal test using extreme difference analysis, the effect tendency of the four parameters to the coating’s performance is gained. The mechanism Analysis is also done in this paper. The optimized combinations of process parameter are obtained with the aim of optimizing each of the coating’s performances and verification tests are also done in this paper.In order to eliminate the difference in dimension, the performance data of the coating is mapped into the scale of [0,1]. The performance of the coating is graded by weight grade method, and then the comprehensive score of the coating is got. Through orthogonal analysis method, optimized combinations of process parameter are obtained and further verification is done by experiment.Repairing connecting rod with nano-composite brush plating technique process not only can get the effect tendency and mechanism of parameters to the coating’s performance, but also improve the repair quality of connecting rod. The research of the project has great theoretical and practical significance, and also provides the theory basis and technical support to engine’s remanufacturing and remanufacture engineering.The work is sponsored by School-enterprise cooperation project between Shandong University and Weichai Power Co. LTD---the key technology of connecting rod’s remanufacturing for engines (11381006).