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Thermal Analysis On Functional Gradient Thermal Barrier Coating Piston With Temperature Dependence

Posted on:2015-02-20Degree:MasterType:Thesis
Country:ChinaCandidate:X R LiuFull Text:PDF
GTID:2251330428958922Subject:Power Machinery and Engineering
Abstract/Summary:PDF Full Text Request
This paper studied that functionally graded thermal barrier coating was applied to the topof the piston to coat. The gradient change of coating material can effectively alleviate thestress between the ceramic layer and the metal substrate and the top layer of ceramicinsulation can play a good role in thermal insulation. Therefore, functionally graded thermalbarrier coating not only have a thermal property with resistance to high temperature andinsulation, but also have mechanical properties of metal.Specific work is as follow:Firstly, the material properties of functionally graded thermal barrier coating werestudied. Ceramic materials such as ZrO2were selected as the insulation material, in themeamwile the piston base material was ZL109. The distribution of material proportion whichfunctionally graded coating was along in the axial direction was determined by usingexponential distribution. Taking into account the actual processing restrictions continuously,variable gradient layer was discrete. And physical parameters (heat conductivity coefficient,elastic modulus, Poisson’s ratio, thermal expansion coefficient) of each gradient coatingmaterial corresponding to different gradient gradient index were calculated.Secondly, the third type thermal boundary contitions,as various parts temperature andheat transfer coefficient,for the steady-state thermal analysis on piston were calculated byusing semi-empirical formula, empirical formula and existing data.Thirdly, a three-dimensional solid model was established in Por/E and the model wasput into model Hypermesh the finite element pre-treatment. Using finite element analysissoftware ABAQUS, steady-state thermal analysis on ordinary aluminum alloy pistons, pureSi-Al alloy piston, pure ceramic piston and the functional gradient thermal barrier coatingpiston with different gradient index was did. Through analysis temperature field and thermalstress field comprehensively, choose the optimal gradient index.Finally, thinking that the temperature of the various parts of the pistons is different andmaterial parameters under different temperatures are different, material parameters thevariation with temperature needed to be determined. In the condition of considering temperature dependence of material, steady state thermal analysis on functionally gradedthermal barrier coating piston was did.
Keywords/Search Tags:Functional Gradient, Thermal Barrier Coating, Temperature Dependence, Piston, Thermal Analysis
PDF Full Text Request
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