The Study Of Three Dimension Simulating Analysis Of Stress Fields And Reliability Design Of Compound Coating

In this paper, both the stress analysis model and failure criterion of the coating/substrate system have been investigated based on the research achievements in home and abroad. A three-dimension FEA model of the coating/metal substrate system has also been developed according to the loading conditions and ANSYS software. The model has been used to analysis and calculation the stresses and distortion's distribution of the coatings. An application has also carried out for coating/substrate system. The main results as follow:The stresses of the coating for bending condition greatly rely on its thickness (short in /) and coating's modulus of elasticity (short in Ec). Near the bending center, the tensile stresses (short in σ) increase with Ec, whereas the shear stresses (short in τ) are very small. However for T , it gets its maximum value at the two sides far from bending center, and the maximum value increase with Ec and t too. And a decrease a lot at the sides.The coating structures also great affect its stresses, some studies show that the max of a and r are in the double coating are lower than in single coating at the same place. It is evident that double coatings can reduce the inner stress of coating and improve its capability instead of single coating.The research results of stresses distribution in coatings under the surface contact conditions show that: cr and T of coatings, which are at same thickness, increase with Ec. If the / is reduced, the maximum value of stress will occur in the inner of coating instead of interface, so that the stress conditions between the coatings and the substrate surface has been improved. This, it is obvious that the coatings with lower Ec and thinner thickness will have the better operating reliability.Based on the achievement above, reliability design for a metal/ceramic coating piston shaft has been carried out and used in engineering.