Orientation-Identified virtual fields method combined with moiré interferometry for mechanical characterization of single crystal Ni-based superalloys. (February 2020)

• Record Type: Journal Article
• Authors: Cao, Quankun; Li, Yangyang; Xie, Huimin
• Is Part Of: Optics and lasers in engineering. Volume 125(2020)
• Publication Date: 2020-02
• Subjects: Moiré interferometry -- Virtual fields method -- Single crystal Ni-based superalloy -- Mechanical characterization; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2019.105854
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: The theory of the Orientation-Identified Virtual Fields Method (OIVFM) is proposed to measure the mechanical properties of the single crystal Ni-based superalloys when the orientation angle is unknown. The Moiré Interferometry is combined with the proposed OIVFM to determine the mechanical parameters of single crystal Ni-based superalloys. The proposed OIVFM can calculate all the in-plane elastic constants even when the constitutive relation is not fully known, and is a promising method for application with other anisotropic materials. Abstract: In combination of the Virtual Fields Method and Moiré Interferometry, a novel method to characterize the elastic constants of single crystal Ni-based superalloys, called the Orientation-Identified Virtual Fields Method (OIVFM), is proposed in this study. The most outstanding advantage of the OIVFM is that it is able to characterize all the elastic constants of a single crystal Ni-based superalloy using a single test without the given parameter of crystal orientation. In this paper, the theory of the OIVFM is firstly introduced in detail to explain the identification process. Simulations and error analyses are conducted to verify the feasibility of the OIVFM. The simulation results match well with the reference values and the error is less than 1 GPa for all the elastic constants. Finally, a single crystal Ni-based superalloy (DD407) is used for the real experiments. Moiré Interferometry is applied to measure the full-field strain, with which the OIVFM is then utilized to calculate the elastic constants of the material. The experiments provide satisfactory results and show a small discreteness. Therefore, it is concluded that the proposed OIVFM can be successfully applied to characterize all the elastic constants of single crystal Ni-based superalloys. By using the OIVFM, it is not necessary to determine the crystal orientation in advance, and as a result, the efficiency of experiment can be improved and its costs can also be reduced.