A novel strategy of regional microstructure design in manufacturing

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.

Automated summary

In this research, a laser heat treatment was applied to a cold-rolled TWIP sample with different gage widths in three parallel regions. It was found that slower laser scanning speed resulted in larger molten pool, greater recrystallized grain size, and lower strength. By adjusting the laser scanning speed, each region could have a suitable microstructure, leading to a slight decrease in loading force but a significant improvement in plasticity. This introduces a new strategy called regional microstructure design (RMD), allowing a single material to have different microstructures instead of using multiple materials with different chemical compositions.