Thermal Fatigue Research On Hot Work Steel With Biomimetic Coupling Surfaces Processed By Laser

At present, 60%-90% industry productions are processed by mould and the total amount of the mould steel is 400 thousand ton per year. The production value of the mould industry is 53 billion RMB in 2004 and is increased to more than 60 billion RMB in 2006. It is estimated that the production value of the mould steel which will increased by 30% on average will increased 60% at the field of the cars and motor cars. Thermal fatigue (TF) is a leading failure of hot working die steels. It has been reported that 60~70% failures have been caused by TF among all the failures of hot working die steels. Therefore, it is of great importance for the development of the economy to improve the TF property of hot working die steels. The TF research of hot work die steels is a representative orientation in the field of the TF research.It is found by biomimetic reach that the nature creatures always choose the best way of their unsmooth shape, surface structure and component buildup to gain the best functions through millions and thousands year's evolutions. It is the coupling functions that form the special features of the organism. Laser can be used to conduct selective and precision manufacture because the heat effective area is small, the direction of the beam is good and the spot of the beam can be focused to the wave length degree. Therefore, the laser has been chosen to process the unsmooth units imitating the configuration from the organisms, such as: the column unit designed from the chest structure of the step armoure creature; the parallel dyke unit designed from the structure on the surface of the shell which is most made of calcium carbonate and with the tiny ingredient of organic substance. The compound system has especially better rupture toughness than man-made porcelain; the tilted dyke and gridding units designed by the structure of the leaves whose veins are made of fiber pipe material with high intensity and toughness. The veins in the leaves act as bones to support the body to repel the changing climate of...