Effect of Electropulsing and Laser Biomimetic Coupling Techniques on the Thermal Fatigue Behaviour of Hot Worked Die Steel
H-X. Yang, C. Meng, G-Y. Song and T-F. Ning
The thermal fatigue of hot worked tool dies improves remarkably when treated with a laser biomimetic coupling technique (LBCT). By processed specific area, the reinforcing structure is built to hinder the spreading of cracks on substrate. Electropulsing is another way to improve steel performance. The processed sample surface has finer the grain and more meandering boundaries that prevent crack from initiation. In this paper, it was utilized to improve the fatigue behaviour of steel hot worked tool dies treated with both methods. The results indicated that the microstructure of the bionic surface was refined by electropulsing. The effects of obstructing crack initiation and extension worked at the same time. Both strengthening method worked together and improve the thermal fatigue performance to a further degree.
Keywords: Nd:YAG laser, AISI H13, hot worked die steel, microstructure, electropulsing, biomimetic coupling, thermal fatigue