| Summary: | 碩士 === 國防大學理工學院 === 車輛及運輸工程碩士班 === 100 === There are many outstanding features of Ni-P and Ni-W-P, such as high performance, good at anti-corrosion, wear impedance and uniformly film thickness, those alloy are applied to the surface coating on all kinds of friction parts and molds. This research is focusing on the applied of Sulphamate-based bath on laser hologram pattern coating, it combines with the mechanical and anti-corrosion. This is mainly about to replace the weakness of Ni-Co using life and insufficient of alloy strengths.
First topic is Ni-Co coating, operating parameters mainly changes the conditions of current density and Co density, in the process of 2 factors, 3 levels by full-factorial experiments. The second part is about the development of Ni-P, investigating the operating parameters changes the operating conditions of frequency and duty cycle, in the process of two factors, three levels by full-factorial experiments, also integrating the Ni and Ni-P as multilayers technology to improve the ing supportive. We perform the plating experiment of three factors, three levels with Ni-W-P, coating P and W double element alloy with high hardness and anti-corrosion. For these work, a rotary frictional test machine will be used to carry out these experiments that adopt the ring on disk, or pin on disk tribo-pairs to simulate the mechanism surface contact and sliding movement. The tribological mechanisms of Ni-based alloy coatings can be clear classified through that the measurements of friction coefficients, wear resistance and the view of wear morphologies combined the elements detected on worn surfaces.
The research show Ni-Co coating, it’s micro hardness is 522 HV, friction coefficient is 0.368, coating weight loss is 0.46 mg, after wearing test, it worn through due to the lack of supportive. From the Ni-P pulse plating experiment, the operating frequency is 100 Hz, duty cycle 50 % are the most affective element against to coating, micro hardness is 662 HV, coating come with low Friction coefficient which is 0.310, the weight loss is 0.23 mg which able to raise the wear resistance doubled. After the heat treatment, the hardness could reach 1085 HV, friction coefficient 0.585. Through the heat treatment, the film instruction changed made the coating embrittlement easily. DC plating Ni-W-P is able to improve the weakness of binary alloy, such as residual stress, deformation…etc., and increasing P content on plating is contributing the improvement of plating instruction. As for the current density on 2 A/dm2 have the best result, deposition content of P ion reached 11.14 wt. %, W ion can reached 4.88 wt. %, and the most micro hardness is 726 HV, plating friction coefficient is 0.466, the minimum weight loss is 0.12 mg, the wear resistance is 3.8 times of Ni-Co, and preparing multi-alloy costing is getting more helping on the upgrading of mechanical quality. Therefore, developing Ni-W-P is able to satisfy precision mold during turning the mold.
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