A novel strategy of regional microstructure design in manufacturing

• Published in: Materials letters 2023-02, Vol.333, p.133644, Article 133644
• Main Authors: Wang, Kun, Cai, Chengyu, Lin, Jixing, Tong, Xian, Tao, Zixiong, Yu, Haicheng, Fang, Qianfeng, Ye, Yuewei
• Format: Article
• Language: English
• Subjects: Laser heat treatment; Microstructure; Recrystallization; TWIP steel
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2022.133644

•A novel strategy of “RMD, regional microstructure design” is proposed.•The laser heat treatment is used to adjust mechanical properties of TWIP steel.•Mechanical properties of the non-uniform TWIP sample are significantly improved. In this research, a cold-rolled twinning induced plasticity (TWIP) sample with three parallel regions with the same gage length of 20 mm but increasing gage widths of 2, 3.5, and 5 mm was subjected to the laser heat treatment. The result shows that the slower the laser scanning speed, the larger molten pool, and the greater recrystallized grain size with lower strength. Thus, by regulating the laser scanning speed, each region in this non-uniform sample could have a suitable microstructure with corresponding mechanical properties, resulting in a slight relative decrease of 3.15 % in the loading force but a massive improvement of 1032.27 % in the plasticity of this sample. This introduces a new strategy known as regional microstructure design (RMD), which allows a product to be made of a single material with different microstructures rather than multiple materials with different chemical compositions.