Cracking Analysis of Low Pressure Turbine Guide Blade of Engine

Low pressure turbine guide blades are one of the important hot end components in engines. The blades work in the high-temperature gas environ-ment and the service conditions are very harsh. After an engine had served for a while, it was found that there were cracks and matrix missing on the surface of a guide blade of the low pressure turbine. The crack property and initiation reason of the blade were analyzed by appearance observation, fracture macro and micro observation, material analysis, gas film holes inspection and thermal simulation test. The results show that the cracks of the blade are fatigue cracks. The thermal barrier coating fell off during the working process of the blade, leading to the overtemperature of the blade tissue and decreasing its fatigue re-sistance, which is the main reason for the initiation of the fatigue cracks of the blade.