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- Maurya, H. S., et al.
(författare)
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Additive manufacturing of TiC-based cermets : A detailed comparison with spark plasma sintered samples
- 2023
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Ingår i: Journal of Alloys and Compounds. - 0925-8388 .- 1873-4669. ; 960
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Tidskriftsartikel (refereegranskat)abstract
- The present work is a comparative study on the TiC-430 L ferritic stainless steel (FSS) cermets manufactured via two powder metallurgical processes, namely, conventional spark plasma sintering (SPS) and metal additive manufacturing (AM) process (laser powder-bed fusion process (LPBF)/selective laser melting (SLM)). The rescanning strategy has been used to preheat and melt the powder bed with different laser parameters during the SLM process to suppress the presence of residual thermal stress leading to the fabrication of cermets without cracks. The as-fabricated SPS samples (95 %) show a relatively lower density than the SLM-built parts (~98 %). A study of their mechanical properties such as hardness, compressive strength, and fracture toughness was conducted and discussed in detail. Further, the corrosion behavior of the fabricated cermets parts was evaluated in 3.5 wt% NaCl. The SLM-prepared specimens reveal finer microstructures and better mechanical properties (compressive strength and fracture toughness) due to the presence of fine microstructure. Furthermore, the corrosion current density of TiC-430 L fss-based cermets fabricated by SLM is approximately 270 times lower than that of cermets parts fabricated by SPS, indicating excellent corrosion resistance. On the other hand, the hardness shows an opposite trend, where the SPS samples show the maximum hardness as compared to the SLM counterparts due to the presence of hard and coarse TiC particles along with some metallic carbides formed during the SPS process. The results reveal that AM processes not only can fabricate cermets with intricate shapes but can also fabricate them with improved mechanical and corrosion properties.
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| 2. |
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| 3. |
- Maurya, H. S., et al.
(författare)
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Investigation of the tribological behavior of the additively manufactured TiC-based cermets by scratch testing
- 2023
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Ingår i: Journal of Alloys and Compounds. - 0925-8388 .- 1873-4669. ; 959
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Tidskriftsartikel (refereegranskat)abstract
- This study deals with the tribological behavior of the TiC-430 L SS cermets fabricated via an additive manufacturing process such as laser powder bed fusion/selective laser melting. A gradient microstructure (finer and coarser morphology) can be observed in the fabricated parts due to SLM's complex thermal history. Using Rockwell indenter, single and multiple passes scratch tests have been performed as a function of applied load to study the wear mechanism of the binder and matrix phase. A surface 3D profilometer was used to analyze the scratch track variation in terms of scratch width and depth. Scanning Electron microscopy (SEM) analysis was performed on the scratched cermet parts to study the wear mechanism and microstructural analysis. It has been observed that the scratch hardness increases with increasing load and the same decreases with increasing the number of passes. Similarly, the coefficient of friction increases with increasing load. Cermets with complex microstructural features exhibit high wear resistance under low loads and for higher loads, multiple passes can lead to tribolayer formation.
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| 5. |
- Maurya, Himanshu Singh, et al.
(författare)
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Synergistic effect of Nb and Mo on the microstructural formationof the Ti(C,n)-high chromium ferrous-based cermets
- 2024
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Ingår i: International journal of refractory metals & hard materials. - : Elsevier. - 0263-4368. ; 122
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Tidskriftsartikel (refereegranskat)abstract
- In this study, Ti(C,N)-Fe-based green cermets with different metallic alloying elements have been consolidated by pressureless liquid-phase sintering. The addition of different metallic binders on Ti(C,N)-based cermet such as Nb and Mo on high chromium Ferrous based binder has been investigated. Detailed analysis of the phase constitution was conducted using thermodynamic calculations and experiments, as well as a systematic study of the microstructure evolution and room temperature mechanical properties including hardness and fracture toughness was conducted. The Nb and Mo addition to the binder system affects the sintering temperatures and can significantly affect the phase formation and microstructural development. Scanning electron microscope (SEM) and Energy dispersive spectroscopy (EDS) technique were used to examine the microstructure, composition, and fracture surface of cermets. The addition of the Mo, and Nb reveals lower porosity and finer microstructure as compared to the reference material (Ti(C,N)-Fe-Cr). The refinement of microstructure improves mechanical properties such as hardness and fracture toughness of Ti(C,N)-Fe-Cr-Mo-Nb-based cermets. Further, the addition of these binder elements may reduce the formation of Fe-Cr-based intermetallic complex carbides, allowing cermets to perform better in terms of toughness and corrosion resistance. As a result of the experiments, it is evident that Nb and Mo dissolve in Ti(C,N) and form solid solutions during sintering. The increased number of coreless grains, spinodal decomposition, and crack deflection in cermet further enhance the fracture toughness.
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