0000000000340467
AUTHOR
Shaowu Liu
Optimization and Improvement of a Novel HVOF Process Fueled with Ethanol
The high velocity oxy-fuel (HVOF) spray has become a process of choice for producing high performance cermet or alloy coatings. Common HVOF thermal spray systems classically use the combustion of gases, such as hydrogen, propane or a liquid fuel such as kerosene. However, there is currently a limited amount of literature on the use of ethanol as a fuel within HVOF processes and the performances of the resulting coatings are not well documented. Ethanol benefits from environmentally friendly features and is less polluting compared to conventional fossil liquid fuels (i.e. kerosene) as its combustion generates less nitrogen oxides and soot particles. In this work, we decide to investigate suc…
Bonding behavior of Bi-metal-deposits produced by hybrid cold spray additive manufacturing
Abstract Cold spraying (CS) is one of the most recently used additive manufacturing (AM) processes that allow forming large 3D objects efficiently without severe thermal effects. However, due to some limitations of the CSAM process, it is difficult to achieve the desired geometry with high precision. As a potential solution to this issue, CSAM process coupled machining, that is, hybrid addition and subtraction manufacturing, is proposed to achieve desired accuracy and reliable shape. Therefore, it is necessary to assess the mechanical reliability of multilayer deposits deposited by CSAM + machining processes before that. In this work, different bi-deposits were obtained via hybrid CSAM. The…
Influence of spray trajectories on characteristics of cold-sprayed copper deposits
Abstract Industrial robots are widely used in cold spray (CS) as well as thermal spray to produce various coatings by precisely controlling kinematic parameters during the process. However, the robot trajectory and its effect on the characteristics of CS deposits are important, but not fully studied. This article introduces four typical spray trajectories, including zigzag path, cross path, parallel path, and spiral path, to elaborate thick CS Cu deposits, and characterizes the corresponding Cu deposits, respectively. The experimental results revealed that the spray trajectories have a major influence on the associated thermal history and the residual stress distribution. However, no signif…
Method for Identifying In-Flight Particles based on Digital Image Technologies in Thermal Spraying
Abstract In thermal spray processes, the characteristics of in-flight particles (velocity and temperature) have a significant effect on coating performance. Although many imaging systems and algorithms have been developed for identifying and tracking in-flight particles, most are limited in terms of accuracy. One key to solving the tracking problem is to get an algorithm that can distinguish different particles in each image frame. As the study showed, when noise and interference are treated, particles are more readily identified in the background, leading to more accurate size and position measurements with respect to time. This approach is demonstrated and the results discussed.