Thermal Shock on Cylinder Head Induced by High Power Laser

Experiment of thermal shock was conducted by laser on cylinder head of graphite cast iron. Infrared pyrometers were mounted on the top of the workbench to sample the transient surface temperatures. The high resolution CCD camera was employed to sample transient images of the cylinder head. Microstructure of thermal shocking specimen was characterized by scanning electron microscopy (SEM) and optical microscope (OM). Mechanical properties of thermal fatigue specimen were evaluated by hardness. Results show that microstructure and hardness are not obviously changed, which mean that cylinder head of graphite cast iron has performance stabilization within the rang of thermal shocking temperature.