HVAF air supersonic thermal spraying system was developed by Lijia , which represents the frontier breakthrough of high-speed coating deposition technology. This system uses compressed air to replace pure oxygen as the main oxidant, which not only ensures the coating compactness and ultra-high bonding strength, but also has operational safety and cost effectiveness, becoming the upgrading solution of traditional HVOF technology.
The core of the HVAF technology is the controlled combustion of compressed air with propane to create a high velocity flame flow in a water cooled combustor. The metal or cermet powder is injected into the flame center through the axial powder feeding system, heated to the semi-molten state and collided with the matrix at supersonic speed to form a dense coating with mechanical occlusion and metallurgical combination, and the oxidation rate is less than 2%.
Zhengzhou Lijia's HVAF system integrates a number of patented technologies, including a two-stage combustion nozzle and an adaptive air-fuel ratio control system to optimize particle kinetic energy and coating uniformity. For complex geometry structures such as turbine blade rabbet and hydraulic valve cavity, the system is equipped with a 6-axis mechanical arm and a programmable rotary table, with a repeatable positioning accuracy of ± 0.03mm to achieve high-precision coating.
Zhengzhou Lijia has established a strict quality assurance system for HVAF system. Each equipment has passed the metallographic section analysis, micro-hardness test and hydraulic pull-out adhesion test before delivery. Environmental stress tests further validate the durability of the coating under simulated conditions. For special needs, the company can customize the HVAF solution with mobile deployment capabilities to consolidate its leadership in the field of flexible, high-value added thermal spraying technology.
