Abstract: The influence of laser power and scanning velocity on interface bonding between clad layer and substrate and uniformity of microstructure in composite surface layer was studied. By means of adjusting these parameters,the excellent interface bonding and uniform microstructure can be obtained. The experiment results show that when the laser power is in a certain value,the lower scanning velocity leads the surface of substrate ahead of laser beam to maintain a longer time at high temperature,so that an oxide film is formed. But,if the scanning velocity is too fast,the synthetic reaction in powder materials near the substrate will be not enough. Either of these two situations will deteriorate the interface bonding. The experiment results also show that the lower the laser input specific energy is,the worse the uniformity of microstructure will be. This phenomenon is caused by insufficient synthetic reaction in powder materials. When the laser power is 2200~2500W,the scanning velocity is 7~10mm/s, an excellent TiCp/Al composite surface layer can be obtained on ZL104Alalloy.
Influence of technological parameters on interface bonding and structure uniformity of in-situ synthesis TiCp/Al composites in laser cladding process
Abstract:
The influence of laser power and scanning velocity on interface bonding between clad layer and substrate and uniformity of microstructure in composite surface layer was studied. By means of adjusting these parameters, the excellent interface bonding and uniform microstructure can be obtained. The experiment results show that when the laser power is in a certain value, the lower scanning velocity leads the surface of substrate ahead of laser beam to maintain a longer time at high temperature, so that an oxide film is formed. But, if the scanning velocity is too fast, the synthetic reaction in powder materials near the substrate will be not enough. Either of these two situations will deteriorate the interface bonding. The experiment results also show that the lower the laser input specific energy is, the worse the uniformity of microstructure will be. This phenomenon is caused by insufficient synthetic reaction in powder materials. When the laser power is 2?200~2?500?W, the scanning velocity is 7~10?mm/s, an excellent TiC p/Al composite surface layer can be obtained on ZL104Al alloy.
Fig.5 Microstructure of clad layer and interface bonding between clad layer and substrate when laser power is 2 500 W and scanning velocity is 7.5 mm/s (input specific energy is 133 J·mm-2) (SEM)