界面平均温度和压力对DD5和1Cr11Ni2W2MoV材料接触热阻影响的实验研究

Experimental study on the influences of mean interface temperature and pressure on thermal contact resistance of the material DD5 and 1Cr11Ni2W2MoV

测量航空发动机重要部件材料间接触热阻对发动机温度分布的准确评估十分重要,进而能为其部件优化设计、叶顶间隙控制和材料热防护提供重要参考价值。DD5和1Cr11Ni2W2MoV材料因具有良好的综合性能和优异的热疲劳和工艺性能而分别广泛应用于航空发动机涡轮叶片和机匣等部件。基于发动机连接部件界面实际工况,根据稳态热流法实验测量上述两材料接触热阻,并研究界面压力(45~200 MPa)和温度(150~300℃)对其影响。研究结果表明:接触热阻与界面压力和温度均存在幂律关系,且随两者增大而逐渐减小;相同界面压力和温度下,1Cr11Ni2W2MoV材料接触热阻比DD5的更小,但两者差距随压力增大而逐渐缩小。此外,拟合得到的两种材料接触热阻与界面压力和温度间的经验公式能较好地预测实验结果,与92.9%的实验数据相对误差小于12%。

Measuring the thermal contact resistance for the material of key component in aeroengine is very essential for accurate evaluation of temperature distribution about engine,which in turn could provide important reference value for the optimization design of its component,control for tip clearance and thermal protection for material.The material DD5 and 1Cr11Ni2W2MoV,which have good comprehensive properties and excellent thermal fatigue as well as process attributes,are widely used in aero-engine turbine blade and casing,respectively.Based on the actual working conditions of the interface of the engine connecting parts,the thermal contact resistance for the above two materials are measured experimentally according to the steady-state heat flow method,and the influences of interface pressure between 45 MPa and 200 MPa,and temperature ranging from 150℃and 300℃on it are investigated.The research indicates that thermal contact resistance displays a power-law relationship with the interface pressure and temperature,and gradually decrease with the increase of them;under the same contact pressure and temperature,thermal contact resistance of the material 1Cr11Ni2W2MoV is smaller than that of DD5 while the gap between both progressively narrows as the pressure grows.In addition,the empirical formulas of thermal contact resistance with the interface pressure and temperature for the two materials are obtained,which could predict the experimental results well,and the relative error with 92.9%of the experimental data is less than 12%.