The multi-layer ceramic/metal gradient cylinder model is useful for many cnginceringcanses. The heat transfer in the cylinder with coating inside is calculated by analytical method andfinite clement method. The thcrmal stress in a single layer gradient cylinder suffering, eventemperature and a multi-layer gladient cylinder with coating inside suffering uneven temperature isrespectively analzed finite difference method, finite element method and zonced-uniform method.The results show that finite clement method agrees well With analytical method in thc heat transferanalysis; finite difference method, Iinitc clement method and zoned-uniform method agrcc well witheach Other in the thermal stress analysis.

A kind of gradient thermal and environmental barrier coating (TBC-EBC) applied ininternal combustion engine is brought forward to improve its working reliability, emission behaviorand cconomical efficiency. The performance modeling for TBC-EBC is carried carried for heat transfer.thermal stress and calulytic reaction. The multi-layer plate model and multi-layer cylinder model areestablished for the simulations of heat transfer and thermal stress in the coatings. Both the theoreticalanalysis and the numerical analysis with multi-layer cylinder modek: are carried out and compared. lheanalysis results show good agreement. The reforming reaction model is also cstablished for catalylicperformance of the coatings based on kinetics choinical reaction and experiments

Four Coating schemes and two substrate materials. i.e, 2Crl3 and 1Cr18Ni9Ti, are designed to evaluate the charaecteristics of the ceramic/metal gradient thermal barrier coating. For all the coating schemes, ZrO2 is used as ceramic and NiCr/Al as bond metal. The gradient coating is successfully prepared by plasma spray with single torch and single feeder. Tje coating and thermal residual stress, The coating micro-structure is observed by scanning electron microscope (SEM). Diffractive peaks for the gradient coating are got at different zone by X-ray spectroscopy (XRS). In the thermal shock test, the microstructure of the specimens is obscrved before and after the experiment, and cracks are found in the coatin post the experimetn. The thermal shock experiment shows that the thermal shock resistance property of the gradient coating is better than that of the non-gradient coating. The measurments of thermal residual stresses in different coating schemes are carried out by hole-drilling method. the results show that compressional stress resents on 1Cr18Ni9Ti substrate and tensile stress presents on 2Crl3 substrate.

The themomechanical stress analysis aims at the thermal and mechanical response of LPG vessel under high thempeature environment. It includes the ealculation of temperature field and stress field of LPG vessel. The finite elements analysis software ANSYS is used to calculate the temperature field. The themal boundary conditions of LPG vessel are determined according to the heat transfer theory and calculated by the software PLGS99. The transient stress of LPG vessel includes transient thermal stress and transient mechanical stress. The thermal stress is calulated by applying thermal load, and the mechanical stress is calculated by applying pressure load of the steam in the vessel. The total stress is obtaince by adding the thermal stress and the mechanical stress. The reults show that the maximum stress in the vessel appears near the highest surface where the liquid cal reach, that the maximum cquivalent thermal stress is much larger than the maximum equivalent mechanical stress. and that the temperature gradient in longitude direction is the main reason that leads to the failure of the vessel.

The air plasma spray (APS) technology is used to prepare WC/NiCrA1 and WC/NiCrBSi ceramic/metal composite wear protective coating on cast iron substrate, and the coating is measured for rnicrostmcture, microhardness, bond strength and slurry wear protective performance. and coating containing more WC is supreme than that containing less WC. Finally, wear mechanics and the principle of the coating's wear protective property are concluded, which are helpful for the design of wear protective coating.