Surface hardening of titanium by laser surface alloying using polyvinyl alcohol film

Abstract

Laser surface alloying of commercial pure titanium pre-coated polyvinyl alcohol (PVA) film was carried out to improve wear resistance. The laser beam is absorbed at the surface of titanium substrate because the PVA film is transparent to the wavelength of a Yb-fiber laser. Thermal decomposition of the PVA occurred at the interface of the titanium substrate and PVA film. A crack free modified layer was obtained by the reaction of these thermal decomposition products and a titanium melt pool at the interface of the film and the substrate. A Ti(C,O) precipitation layer was formed on the surface layer of the laser alloyed zone. The laser alloyed zone exhibits superior wear resistance.Laser surface alloying of commercial pure titanium pre-coated polyvinyl alcohol (PVA) film was carried out to improve wear resistance. The laser beam is absorbed at the surface of titanium substrate because the PVA film is transparent to the wavelength of a Yb-fiber laser. Thermal decomposition of the PVA occurred at the interface of the titanium substrate and PVA film. A crack free modified layer was obtained by the reaction of these thermal decomposition products and a titanium melt pool at the interface of the film and the substrate. A Ti(C,O) precipitation layer was formed on the surface layer of the laser alloyed zone. The laser alloyed zone exhibits superior wear resistance.