Dongling Li1,3*, Guiyong Wang2,4, Xuejing Shen1,2, Haizhou Wang1,4
1Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing 100081, China;
2NCS Testing Technology Co.,Ltd., Beijing 100081, China
3Central Iron & Steel Research Institute, Beijing 100081, China
4Beijing Key Laboratory of Metallic Materials Characterization, Beijing 100081,China
EXTENDED ABSTRACT: With the gradual expansion of the application scenarios of engineering structural materials, engineering components have the trend of large-scale and complex development, and the non-uniformity of their mechanical properties at different parts also tends to be obvious. It is necessary to characterize the distribution of mechanical properties in all areas of components, which also brings about the problem that the sample size is greatly reduced and the number of samples tested is doubled. Therefore, it is necessary to develop high-throughput mechanical property characterization technology to meet the requirements of large and complex engineering structural materials. A miniature tensile properties testing system with six channels was developed and the electromechanical system, control system and data acquisition system were designed and optimized. Some small-scale specimens with diameters ranging from 0.5mm to 2.5mm were measured and it was found that the test results of the system had good accuracy and the data between different channels had good reproducibility. The system has been used to characterize the tensile properties of small-scale specimens of engineering structural materials such as high-speed railway wheel rims and polycrystalline superalloys for aeroengine turbine disks. The test results show that the tensile properties of the wheel rims of high-speed trains had a tendency to decrease gradually within the depth of 50mm from the tread. The change of the microstructure inside the wheel rim tread has an important impact on the tensile properties of the micro zone. With the increase of pearlite lamellar spacing, the tensile strength and yield strength gradually decreased and a mathematical model for the correlation between the tensile properties of the wheel rim and the microstructure has been established, which provides theoretical and technical support for the in-depth study of the strength and toughness mechanism of high-speed railway wheel materials and the improvement of the heat treatment process.
Keywords: High-throughput tensile properties testing system; Small specimen; Railway wheel; High temperature alloy; Pearlite lamellar spacing
Dongling Li has completed her PhD from central iron and steel research institute, She is the professor of NCS Testing Technology Co.,Ltd and has published more than 100 papers in reputed journals and has been serving as an editorial board member of two journals. As the project leader, She has undertaken many national key research and development plans.