2004 Fiscal Year Final Research Report Summary
Study on Unified Understanding of Fundamental Coating Steps in Reactive Thermal Sprayings
| Project/Area Number |
14350404
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Metal making engineering
|
|---|
| Research Institution | Toyota Technological Institute |
|---|
Principal Investigator |
TSUNEKAWA Yoshiki Toyota Technological Institute, School of Engineering, Professor, 工学部, 教授 (50148350)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OKUMIYA Masahiro Toyota Technological Institut, e School of Engineering, Asso. Professor, 工学部, 助教授 (20177182)
FUKUMOTO Masahiro Toyohashi Univ., of Technology College of Engineering, Professor, 工学部, 教授 (80173368)
|
|---|
| Project Period (FY) |
2002 – 2004
|
| Keywords | DC Plasma Spraying / HVOF Spraying / RF Plasma Spraying / InProcess Reaction / Wettability / InSitu Composite / Droplet Temperature / Droplet Velocity |
|---|
| Research Abstract |
If composite powders consisted of multi-constituents are sprayed, it is worried about the decomposition of thermodynamically unstable species may occur in their spraying process. However, reactive spraying is quite effective to form in-situ composite coatings, because the required and thermodynamically stable compounds can be synthesized by the in process reaction. Following results are obtained in this study :
(1) Cast iron coatings with solid lubricant of graphite were formed by DC plasma spraying for the surface modification of aluminum substrates. Specially designed cast iron powder, which were alloyed with high silicon and aluminum of strong graphitizer, were supplied as a spray material. In order to form cast iron coatings with graphite structure, (a) pre-annealing of cast iron powder, (b) post annealing of sprayed coatings and (c) mixing with additional solid lubricant of hBN. The cast iron coatings with graphite structure exhibits mood tribological properties.
(2) Alloyed powder of Al-40wt%Si-10wt%Mg were sprayed by DC and RF plasma spraying, and also HVOF spraying. HVOF spraying gives the highest hardness among them due to refined microstructure and work hardening. The evaporation of magnesium occurs during the RF plasma spraying process, which causes less reinforced phase of Mg_2Si. It is expected that the in process reaction of SiO_2 reduction give us in situ composite coating in the case of Al-Si Mg powder mixed with SiO_2. The coatings with DC plasma spraying show the highest hardness, that is, the highly proceeded in process reaction, because it causes the high amount of MgAl_2O_4 due to the optimum droplet temperature.
|
Research Products
(13 results)
