Evaluation of the quality of laser cladding layer of the pros and cons, mainly from two aspects to consider. First, the macro level, examining cladding Road, shape, surface roughness, cracks, porosity and dilution rate; second is the micro level, examining whether the formation of well organized, can provide the required performance. In addition, the surface should be measured cladding types and distribution of chemical elements, carefully analyze whether the transition layer of metallurgical bonding, if necessary, to conduct quality of life testing.
Current research work is focused on research and development equipment, cladding, bath dynamics, the design of alloy composition, crack formation, expansion and control methods, as well as between the cladding layer and the substrate combination of ability.
At present further application of laser cladding technology, the main problems facing are:
① laser cladding technology in China has not yet fully realized the industrialization is mainly due to the quality of cladding layer instability. Laser cladding process, the heating and cooling fast speeds of up to 1012 ℃ / s. As cladding layer and substrate materials, the temperature gradient and thermal expansion coefficient differences, may generate a variety of cladding layer defects include holes, cracks, deformation, and surface roughness .
② deposition process of optical testing and implementation of automatic control.
③ cracking sensitivity of laser cladding layer is still troubled by domestic and foreign researchers a problem as well as engineering application and industrialization of the barrier . At present, although the formation of crack extension has been studied , but the control methods are not yet ripe.