Author Affiliations
1College of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300, China2Laser Technology Institute, Tiangong University, Tianjin 300387, Chinashow less
Fig. 1. Powder morphologies. (a) NiCu; (b) WC
Fig. 2. Schematics of DED of circular oscillation laser. (a) Schematic of equipment; (b) oscillation trajectory and deposition process
Fig. 3. Schematic of test process
Fig. 4. XRD patterns of NiCu and NiCu/30%WC composites
Fig. 5. Macro-morphologies of deposition layers. (a) NiCu; (b) NiCu/30%WC composites
Fig. 6. Microstructures of two types of deposition layers. (a) Upper NiCu; (b) central NiCu; (c) lower part of NiCu; (d) upper NiCu/30%WC; (e) central NiCu/30%WC; (f) lower part of NiCu/30%WC
Fig. 7. Comparison of grain sizes of NiCu and NiCu/30%WC composites. (a) Microstructure of NiCu; (b) grain size of NiCu; (c) microstructure of NiCu/30%WC; (d) grain size of NiCu/30%WC
Fig. 8. Crystallization diagrams of NiCu and NiCu/30%WC composites. (a) NiCu; (b) NiCu/30%WC
Fig. 9. EDS scanning results of WC particles. (a) Line scanning result; (b) surface scanning result; (c) Ni element distribution; (d) W element distribution; (e) C element distribution; (f) Cu element distribution
Fig. 10. EDS point scanning areas
Fig. 11. Comparison of microhardness
Fig. 12. Friction and wear test results of NiCu and NiCu/30%WC composites. (a) Friction coefficient curves; (b) mass loss; (c) two-dimensional morphologies of wear scars; (d) three-dimensional morphologies of wear scars
Fig. 13. SEM images of worn surfaces. (a) NiCu; (b) NiCu/30%WC composite
Fig. 14. Wear mechanisms of NiCu and NiCu/30%WC composites
Powder | V | Cr | Fe | W | C | B | Si | Cu | Ni |
---|
NiCu | - | - | - | - | 0.03 | 1.10 | 2.00 | 20.00 | Bal. | WC | 0.001 | 0.023 | 0.200 | 95.000-96.000 | 3.950 | - | - | - | - |
|
Table 1. Chemical compositions of NiCu and WC powders (mass fraction, %)
Parameter | Power /W | Scanning speed /(mm/s) | Spot diameter /mm | Oscillation frequency /Hz | Overlapping ratio /% | Powder feed rate /(g/min) | Argon flow rate /(L/min) |
---|
Value | 600 | 6 | 0.5 | 30 | 50 | 11.3 | 3 |
|
Table 2. Optimum process parameters
Parameter | Diffractive crystal plane | Start angle /(°) | End angle /(°) | Counting time /s |
---|
Value | 311 | 146.0 | 152.0 | 18 |
|
Table 3. Parameters for residual stress test
Point | Mass fraction /% |
---|
W | Ni | Fe | Cu | Cr |
---|
1 | 69.05 | 24.79 | 4.28 | 0.68 | 1.20 | 2 | 65.94 | 26.97 | 5.33 | 0.87 | 0.88 | 3 | 61.35 | 29.54 | 7.11 | 1.00 | 1.00 | 4 | 64.58 | 26.83 | 6.81 | 0.72 | 1.05 |
|
Table 4. Element compositions and mass fractions obtained by EDS scanning at different positions in Fig. 10