Abstract:
In the evaluation process of superalloy grain structure, the single feature mainly based on grain size or grain fineness number is mostly used, which cannot obtain accurate and intuitive evaluation results. To address this problem, a spiral visualization evaluation method for the grain structure reliability of superalloys was proposed. Multiple grain structure features such as grain size, aspect ratio, roundness, etc. are considered, and multiple features are dimensionally mapped to a two-dimensional inner space through circle-like mapping. Taking the minimization of the distance between the mapping point and the helix as the objective function, the undetermined coefficients of the helix and the circle-like mapping were solved by the salps group optimization algorithm, and then the reliability evaluation model of the Fermat helix was constructed. The reliability of the grain structure can be evaluated according to the evaluation model by mapping the distance between the point and the helix. Taking nickel-based superalloy GH4169 as the evaluation object, the results show that the spiral visualization evaluation method can intuitively characterize the reliability of the grain structure. The distance between the mapping point and the spiral is inversely proportional to the reliability, that is, the smaller the distance, the higher the reliability.