|
| Abstract No.: |
|
Scheduled at:
|
Wednesday, May 11, 2016, Room 3E 12:00 PM
Cold Gas Spraying III
|
|
| Title: |
Effect of content and type of reinforcing particles on the hardness and wear rate of low-pressure cold sprayed TiC and B4C-based metal matrix composite coatings
|
|
| Authors: |
Roy Lee* / University of Alberta, Canada
Hossein Ashrafizadeh / Department of Mechanical Engineering, University of Alberta, Canada
Gary Fisher/ Alberta Innovates Technology Futures, Canada
André McDonald/ Department of Mechanical Engineering, University of Alberta, Alberta
|
|
| Abstract: |
A low-cost, low-pressure (less than 1 MPa) cold spray unit was used to deposit boron carbide (B4C) and titanium carbide (TiC)-based metal matrix composite (MMC) coatings. B4C and TiC powders were individually and mechanically blended at 50 wt.%, 75 wt.%, and 92 wt.% carbide content with the remaining weight from nickel (Ni) powder. Scanning electron microscopy (SEM), Vickers micro-hardness, and ASTM Standard G65 dry abrasion wear testing were conducted to analyze the coatings. Image analysis was used to determine the reinforcing carbide content. The impact momentum of the reinforcing carbide particles upon impact was calculated by a mathematical model based on the fundamentals of dynamics and thermodynamics of compressible fluid flow through a converging-diverging nozzle. The model showed that the impact momentum of TiC was three times smaller than that of B4C. A maximum carbide content of 8 wt.% (23 vol.%) for B4C and 18 wt.% (29 vol.%) for TiC in the MMC coating was achieved. The higher deposition efficiency of the TiC particles was most probably due to the lower impact momentum of TiC and, therefore, less fracture and rebound of the brittle reinforcing particles. However, similar hardness and wear rate values were obtained for both coating types due to the higher hardness of B4C. This suggests that by selecting reinforcing particles from harder materials, similar, if not increased hardness values and improved abrasion resistance can be obtained, even with a reduction in volume content of the reinforcing carbide particles in the MMC coating.
|
|