X. Yuan, G. Hou, B. Zha, Xi'an Research Institute of Hi-Tech, Xi'an, China; H. Wang, Xi'an Research Institute of Hi-Tech, Xi’an, China
the fracture behavior of polymer coating fabricated by Low Temperature High Velocity Air Fuel (LTHVAF) spray system was researched. Experiment results show that the coatings are dense with average porosity. The adhesion strength of the coatings is high, the average adhesion strength excesses 13.47MPa. During the tensile stress process, the fracture is occurred in coating interior. The result illustrate that the coating material fracture intensity is less than the binding strength. Plenty of craze and honeycombed hole exit in the fracture surface. The coating fracture mechanisms are that the crackle occurs at the coating objection for the stress focus. However, some dispersive particles hold up the crack expansion, which is obliged to change. So, the coating binding strength can be increased.
Summary: The polymer coatings was fabricated by Low Temperature High Velocity Air Fuel(LTHVAF) Spray technology, which properties was analysized. The coating's micro-structure is dense; the mean bonding strength is 13.47MPa. During the tensiling process, the fracture was occured in the coatings. At the micrographs of fracture surface following tensile testing, there are some Plenty of honeycomb hole, sloping degree is 45° and “Ë” type crack, disorderly craze and some disperse solid particles exist in the coating.The fracture mechanism is that the coating defect causes to intial crack, but the disperse particle interrupts the crack's expansion, the crack trend is changed lastly.
