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Microstructural characteristics and formation mechanism of direct laser-sintered Cu-based alloys reinforced with Ni particles
- Source :
-
Materials & Design . Jun2009, Vol. 30 Issue 6, p2099-2107. 9p. - Publication Year :
- 2009
-
Abstract
- Abstract: Direct metal laser sintering (DMLS) was used to consolidate Cu-based alloy powder (Cu–10Sn and Cu–8.4P) reinforced with Ni particles. Phases, microstructures, compositions, and mechanical properties of laser-sintered part were studied. It showed that particle bonding was through a liquid phase sintering mechanism involving the complete melting of matrix alloy powder and the non-melting of cores of Ni reinforcing particles. A significant smoothening of Ni particles occurred in the liquid and the dissolved Ni element alloyed with Cu element to form CuNi solid solution, leading to a coherent particle/matrix interface after solidification. The dendrites of matrix alloys developed directionally and the primary dendritic spacing was highly refined to ∼1.5μm, due to laser-induced super high temperature gradient and solidification rate. The additive P element acted as a localized deoxidizer to prevent the sintering system from oxidation by formation of CuPO3, thereby enhancing liquid–solid wettability and resultant sintering activity. A high densification level of 95.2% theoretical density was obtained after sintering. The fracture surface of laser-sintered part was mainly featured by a strong ductile type of fracture. The dynamic nanohardness of Ni reinforcing phase and Cu-based matrix alloys reached 1.82GPa and 0.99–1.35GPa, respectively. [Copyright &y& Elsevier]
- Subjects :
- *SINTERING
*COPPER alloys
*POWDER metallurgy
*METAL powders
*NICKEL
*MICROSTRUCTURE
Subjects
Details
- Language :
- English
- ISSN :
- 02641275
- Volume :
- 30
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- Materials & Design
- Publication Type :
- Academic Journal
- Accession number :
- 37345896
- Full Text :
- https://doi.org/10.1016/j.matdes.2008.08.036