In-situ stretching method for evaluating crack propagation of prefabricated notch high-temperature nickel-based alloy

Abstract

The invention relates to a testing method based on in-situ stretching of a scanning electron microscope. The invention aims to provide an in-situ stretching method for evaluating crack propagation of a prefabricated notch high-temperature nickel-based alloy. According to the method, crack propagation evaluation and characterization can be effectively carried out on the high-temperature nickel-based alloy in the high-temperature in-situ tensile test process when the high-temperature nickel-based alloy has the prefabricated notch in the mesoscale (several microns to dozens of microns). According to the technical scheme, the in-situ stretching method for evaluating crack propagation of the prefabricated notch high-temperature nickel-based alloy comprises the following steps: 1) sample processing: processing a high-temperature nickel-based alloy sheet into a sample, and prefabricating a notch in the center of the sample; 2) sample preparation: grinding and polishing the sample to obtain a sample with a smooth and flat surface; 3) performing in-situ tensile test on the sample; and 4) processing and evaluating test data.

Description

technical field [0001] The invention relates to a testing method for in-situ stretching based on a scanning electron microscope, in particular to a method for evaluating crack growth of a prefabricated notch high-temperature nickel-based alloy during high-temperature in-situ stretching. Background technique [0002] At present, the evaluation of crack growth of high-temperature nickel-based alloys at high temperatures (350°C-900°C) in situ stretching generally uses samples with parallel ends and no pre-cracks. (EBSD) probe, heatable in-situ stretching table, for SEM / EBSD in-situ tensile observation of samples at room temperature / high temperature environment. However, since the sample with no notch in the parallel section is used, the crack initiation position is uncertain during the in-situ stretching process, so it is difficult to judge the crack initiation position, and it is difficult to select the original region of interest. In addition, there are still gaps in the eva...

AI Technical Summary

Problems solved by technology

However, due to the use of samples with no gaps in the parallel section, the crack initiation position is uncertain during the in-situ stretching process, so it is difficult to judge the crack initiation position, and it is difficult to select the original region of interest

In addition, there are still gaps in the evaluation and characterization methods for the crack growth of pre-cracked high-temperature nickel-based alloys, including changes in the microstructure in the vicinity of the crack, changes in the misorientation angle distribution, and changes in the strain distribution during the crack growth process. , to be supplemented

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