In The News
- PDF / 406,523 Bytes
- 5 Pages / 593.972 x 792 pts Page_size
- 41 Downloads / 194 Views
News from Research and Technology Institutes Worldwide This column informs JTST readers of activities in research and technology institutes in the field of thermal spray technology. Technical overviews help the reader to understand the primary focus of the institution and the needs driving their thermal spray research and development. Getting to know the research interests and professional experience of our thermal spray colleagues allows us to better recognize experts in specific fields of study. Knowledge of institutional expertise is important for developing complimentary partnering relationships to increase the fundamental understanding of thermally sprayed materials and increase the quality and breadth of practical applications. This column includes articles giving an overview of current activities or a focus on a significant breakthrough. To submit an article for this column, please contact Kendall Hollis, JTST Associate Editor, address: Los Alamos National Laboratory, P.O. Box 1663, MS G-770, Los Alamos, NM 87544; e-mail: kjhollis@ lanl.gov.
benefited enormously from collaborations with NZ companies—Holster Engineering and Metal Spray Suppliers— and international groups such as Paul MunroeÕs Electron Microscope Unit at the University of New South Wales and Sanjay Sampath and the Center for Thermal Spray Research. Carbide Cermets Our initial research centered on highvelocity sprayed cermets, and the evolution of microstructure as a function of spray parameters and in-service conditions. The high-velocity techniques, especially high-velocity air fuel, are particularly suitable since the lower jet and particle temperatures minimize decarburization during deposition. Variations in microstructures of HVAF and HVOF WC-Co coatings were correlated with sliding wear performance (Ref 1, 2). The mechanism of the decarburization process and the formation of decarburized halos has also been elucidated (Ref 3). Parallel work in our lab has confirmed similar behavior for HVAF and HVOF
Thermal Spray Research at the University of Auckland, New Zealand
Journal of Thermal Spray Technology
Figure 1 demonstrates the evolution of microstructure and hardness with heat treatments mimicking the early service life temperatures of turbine coatings. The obvious change is the precipitation of fine carbide structure from the matrix. During coating deposition, some carbide is dissolved in the matrix, which occurs to a greater extent in deposition technologies that heat the particles to higher temperatures (Ref 4). This dissolved carbide precipitates as very fine particles, which grow with longer heat
1300 Microjet Air
Microjet Argon
1250
Vickers Microhardness (HV300)
Thermal Spray Research at the University of Auckland is carried out within the Department of Chemical and Materials Engineering, Faculty of Engineering, and our research programs are naturally influenced by the local strengths and national interests. The Thermal Spray Research Group has strong links with intra-University centers such as the Light Metals Research Centre
Data Loading...
