직류전위차법을 이용한 분말야금 니켈기 초내열합금의 피로균열진전거동 평가

Powder metallurgy Nickel based superalloy is used to manufacture high temperature parts of turbine engine for airplane. In this study, fatigue crack growth tests for the material are conducted by temperature conditions at room temperature and 600 ℃. Evaluation method for fatigue crack growth rate calculated using DCPD method suggested by ASTM E647. From these results, fatigue crack growth rate of the material is higher when stress ratio is 0.5. When stress ratio is 0.1, crack begins from lower stress intensity factor. Fractography was carried out by Scanning Electron Microscope(SEM).