HVAF vs HVOF – Chances and Challenges for Users and Powder Producers

HVAF vs HVOF – Chances and Challenges for Users and Powder Manufacturers Since a few years, the HVAF process has been established commercially and gained its share in the market for thermal spraying. Users who want to invest into thermal spray equipment and need to decide between the competing technologies of HVOF and HVAF, often decide by economic figures preferentially. In this later aspect, HVAF is captivating, especially in case of larger spray system, by high deposition rates and lower cost. On the other side, resulting coatings are different from HVOF coatings and the differences are not straightforwardly obvious. On this topic, many publications and conference contributions have been published. Regrettably, coating characterization is not always complete and field test results are missing in most cases. In effect, potential users of HVAF technology get little support for their decision making from the viewpoint of coating performance. The challenge for powder producers consists in providing suitable spray powders and to be able to make recommendations to the users of HVAF and HVOF technology. Therefore, a deeper understanding of the spray process and particle characteristic in terms of fluid dynamics and material behavior is important.