Study On The Preparation Of Intaglio Plate Wear-resistant Coatings By Means Of Ion Assisted Electron Beam Physical Vapor Deposition

Hard chromium wear-resistant coatings on the intaglio plate materialswere deposited by means of ion assisted electron beam physical vapordeposition (IA-EBPVD), so as to solve the problems of polluting andhydrogen-embrittlement from the electroplating. The influences by equipmentsand technologies on the coatings' depositing & performance are presented.The morphologies and mechanical properties (Hardness, Roughness andAdhesion etc.) were studied using optical metallographic microscopy, scanningelectron microscopy (SEM), atomic force microscopy (AFM), micro-hardnesstester, profile meter, and scratch tester. Some results were analyzed andcompared with those of the electroplated coatings. The results show that: 1. It is feasible to obtain Cr wear-resistant coatings on intaglio plate byIA-EBPVD with optimized equipments and technologies. The hardness canreach or even surpass that of the electroplated one. The roughness of thesurface is almost the same as the latter. The adhesion can reach that of theelectroplated due to the introduction of the optimized process. 2. The ion bombardment is of primary importance during the deposition.It's difficult to obtain perfect adhesive coatings without ion bombardment.Other technologic factors, such as substrate-pretreating, interlayer andoperating parameters of the electron gun, can influence the coatings' growth,microstructure and mechanical properties. 3. Grains with the size of 50～250nm are observed by AFM on thesurface. The size and arrangement of the grain on different coatings whichwere deposited via different process are different. The grains are much finer insize and much compact in arrangement as the result of ion bombardment,which is useful to improve the performance of the coatings. 4. Interlayer or interface between the coating and substrate can be IIobserved on the sectional view by SEM. The thickness of the interlayer isabout 100～200nm. Ion bombardment can result in slight diffusion betweenthe interfaces, resulting in improvement of the performance of the coatings. 5. There are some micro-gaps, micro-holes and impurities in thecoatings, which is the primary reason of degrading the performance of thecoatings. The flaws can be reduced with optimized equipments andtechnologies.