Achieving High Strength-plasticity of Nanoscale Lamellar Grain Extracted from Gradient Lamellar Nickel

• Published in: Chinese journal of mechanical engineering Vol. 35; no. 1; pp. 58 - 12
• Main Authors: Wang, Zimeng, Jia, Yunfei, Zhang, Yong, Tang, Pei, Zhang, Xiancheng, Tu, Shantung
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.12.2022; Springer Nature B.V; SpringerOpen
• Edition: English ed.
• Subjects: Compression test; Compression tests; Deformation effects; Deformation mechanisms; Dislocation; Edge dislocations; Electrical Machines and Networks; Electronics and Microelectronics; Engineering; Engineering Thermodynamics; Grain boundaries; Heat and Mass Transfer; Heat treatment; High strength; Instrumentation; Intelligent Manufacturing Technology; Lamellar structure; Machines; Manufacturing; Mechanical Engineering; Mechanical properties; Nanoscale lamellar structure; Original Article; Plastic properties; Power Electronics; Processes; Slip; Stacking fault energy; Strain hardening; Theoretical and Applied Mechanics; Thickness; Ultrasonic testing; Compression test; Slip; Nanoscale lamellar structure; Dislocation
• ISSN: 1000-9345; 2192-8258
• DOI: 10.1186/s10033-022-00738-9

Traditional metallic materials usually face a dilemma between high strength and poor strain hardening capacity. However, heterogeneous structured metallic materials have been found to obviously overcome the trade-off. Herein, gradient lamellar structure was fabricated through ultrasound-aided deep rolling technique in pure Ni with high stacking fault energy after heat treatment. The gradient lamellar Ni was successively divided into the four regions. In-situ micropillar compression tests were conducted in different regions to reveal the corresponding microscopic mechanical properties. Microscopic characterization techniques were performed to explore underlying deformation mechanisms and the effects of microstructural parameters on deformation behaviors. This work demonstrates that the micropillar with near nanoscale lamellar thickness possesses excellent strength and plasticity. On one hand, the reason for high strength of near nanoscale micropillar is that the strength of micropillar increases with the decrease of lamellar thickness according to the Hall-Petch effect. On the other hand, numerous lamellar grain boundaries perpendicular to the loading direction is found to hinder the motion of slip bands, resulting in great strain hardening capacity in the near nanoscale lamellar micropillar.