| 1. |
- Mathiyalagan, Sribalaji, et al.
(författare)
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Deposition characteristics and tribological performance of atmospheric plasma sprayed diamond metal matrix composite (DMMC) coatings
- 2024
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Ingår i: Materials Chemistry and Physics. - : Elsevier Ltd. - 0254-0584 .- 1879-3312. ; 315
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Tidskriftsartikel (refereegranskat)abstract
- Diamond-reinforced metal matrix composites (DMMC) have great potential for wear-resistance applications due to the superior hardness imparted by diamond. Atmospheric plasma spraying involving axial injection of suitable feedstock is a convenient pathway to fabricate DMMC coatings for tribological applications. In this paper, thick DMMC coatings were deposited by plasma spraying Ni–P clad diamond particles under varying spray conditions. It was found that the phase characteristics of DMMC coatings as well as extent of diamond retention and fragmentation were significantly influenced by spray conditions such as, stand-off distance (SOD) and carrier gas flow rate (CGFR). Mechanical characterization (by micro-indentation) on all DMMC coatings developed in this work showed that coatings sprayed with longer SOD and higher CGFR has relatively higher hardness than other two coatings. However, on nanoindentation, the diamond hardness was found overestimated due to effect of diamond roughness on fragmentation. Ball-on-disc wear testing showed excellent tribological properties in all cases, with enhanced wear performance being noted when more diamond is retained in the coating. © 2024
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| 2. |
- Mathiyalagan, Sribalaji, et al.
(författare)
-
High velocity air fuel (HVAF) spraying of nickel phosphorus-coated cubic-boron nitride powders for realizing high-performance tribological coatings
- 2022
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Ingår i: Journal of Materials Research and Technology. - : Elsevier Editora Ltda. - 2238-7854. ; 18, s. 59-74
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Tidskriftsartikel (refereegranskat)abstract
- High velocity air fuel (HVAF) spraying is an emergent thermal spray process, which is used in this work to realize high-performance large area tribological coatings of nickel-phosphorus cladded cubic-boron nitride (c-BN) particles. To the best of authors’ knowledge, this is the first time that HVAF has been utilized for developing Ni–P coatings reinforced with c-BN (NBN). The importance of appropriate processing was highlighted by utilizing two different nozzle configurations, for which microstructure, phase analysis and hardness results demonstrates considerable differences. Furthermore, the coatings were subjected to sliding wear tests to assess their friction and wear characteristics. Post-wear SEM analysis reveals the associated wear mechanisms. Effect of annealing on tribological performance of NBN coatings was also examined, and it is shown that optimal processing can preclude the need for post-treatment. Results ensuing from this work lay the foundation for new generation of HVAF-sprayed wear resistant metal/c-BN composite coatings for diverse applications. © 2022 The Author(s)
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| 3. |
- Owoseni, Tunji A., et al.
(författare)
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Microstructure and Tribological Performance of HVAF-Sprayed Ti-6Al-4V Coatings
- 2023
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Ingår i: Coatings. - : MDPI. - 2079-6412. ; 13:11, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Ti-6Al-4V is a widely used titanium alloy in aviation and bio/chemical applications for its attractive mechanical and corrosion resistance properties. The use of Ti-6Al-4V as a coating for repair purposes through thermal spray techniques provides a unique productivity opportunity. A repair coating must be dense to provide the required in-service functionalities, such as resistance to wear. The High Velocity Air Fuel (HVAF) thermal spray technique deposits dense coatings with reduced concern for oxide inclusions. This work presents an investigation of the microstructure, dry sliding, and solid particle erosive wear performance of four different coatings engineered through the configuration of the nozzle of an HVAF spray gun, based on the length of the nozzle and the size of the nozzle exit. A long nozzle length and wide nozzle exit mean increased inflight dwell time and reduced average inflight temperature for the sprayed particles, respectively—a reversed configuration means the opposite. The tested coatings showed a porosity of less than 2%. The sliding and erosion wear performance of the densest of the coatings compares to that of the bulk material tested under the same conditions. Electron microscopy was used to investigate the driving mechanisms for the performance of the respective coatings. The implications of the results are discussed for the potential adoption of HVAF-sprayed coatings in metal component repair.
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| 4. |
- Rossetti, Matteo, et al.
(författare)
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Advanced diamond-reinforced metal matrix composite (DMMC) coatings via HVAF process : Effect of particle size and nozzle characteristics on tribological properties
- 2023
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Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 49:11 Part A, s. 17838-17850
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Tidskriftsartikel (refereegranskat)abstract
- High-velocity air fuel (HVAF) spraying is a versatile and cost-effective platform to fabricate wear resistant coatings. In this work, deposition of Nickel–Phosphorus cladded diamond feedstock is explored as a greener alternative to realize highly wear resistant large-area coatings. To the best of authors knowledge. this is the first study that has utilized HVAF technique for developing wear resistant Ni–P coatings reinforced with diamond (NCD). This work also aims to understand the effect of particle size by using coarse (20–30 μm) and fine NCD (10–15 μm) particles as feedstock. The importance of utilizing appropriate processing conditions was also highlighted by using two different nozzle configurations, for which the two powder particle sizes exhibited considerable differences in terms of microstructure, phase characteristics and mechanical properties. Further, the effect of annealing on the above coating characteristics was also examined, and it is shown that optimal spraying conditions can preclude the need for post-treatment. Furthermore, the as-deposited and annealed coatings were subjected to sliding wear tests to assess their tribological performance. Post-wear analysis performed on worn surfaces revealed the associated wear mechanisms. The results ensuing from this work lay the foundation for realizing new generation of HVAF sprayed wear resistant Ni–P/diamond composite coatings for diverse applications.
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