Laser Cladding for Diamond-Reinforced Composites with Low-Melting-Point Transition Layer
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-05-21 |
| Journal | Materials |
| Authors | Yongqian Chen, Yifei Du, Jialin Liu, Shanghua Zhang, Tianjian Wang |
| Institutions | Huaqiao University, Zhengzhou University of Aeronautics |
| Citations | 1 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis research introduces an innovative laser cladding strategy utilizing a low-melting-point transition layer (LTL) to overcome thermal degradation and interfacial failure in diamond-reinforced metal matrix composites.
- Core Innovation: Pre-depositing an Inconel 718 (IN718) nickel-based alloy LTL on a 45 steel substrate to regulate the molten pool temperature and suppress diamond graphitization during laser cladding.
- Thermal Management: The IN718 LTL (Melting Point: 1392 °C) significantly reduces the peak molten pool temperature compared to the 45 steel substrate (1500 °C), effectively mitigating thermal-induced graphitization.
- Interfacial Optimization: The LTL acts as a diffusion barrier, blocking the migration of Fe atoms from the substrate into the cladding layer, thereby weakening Fe-C interfacial catalytic reactions that promote graphitization.
- Graphitization Suppression: Raman spectroscopy confirmed that samples with the IN718 LTL completely inhibited diamond graphitization at both 600 W and 800 W laser power, whereas non-LTL samples showed progressive graphitization.
- Microstructural Improvement: The LTL enhanced the wetting behavior of the matrix alloy toward diamond, leading to improved diamond encapsulation efficiency and reduced interfacial sintering defects.
- Tribological Performance: Transition-layer samples exhibited significantly enhanced wear resistance, achieving a friction coefficient of 0.45 at 1000 W laser power, a substantial reduction compared to 0.561 for non-LTL samples.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Substrate Material | 45 Steel | N/A | Base material. |
| Substrate Melting Point | 1500 | °C | High melting point of 45 steel. |
| Transition Layer Material | Inconel 718 (IN718) | N/A | Low-Temperature Layer (LTL). |
| IN718 Melting Point | 1392 | °C | Reduces molten pool peak temperature. |
| Diamond Graphitization Threshold | 850 | °C | Critical temperature in air (Reference [19]). |
| Composite Volume Ratio | 80:20 | % | IN718:Diamond. |
| Diamond Particle Size | 100 | mesh | Used to prevent thermal ablation. |
| LTL Preparation Laser Power | 1100 | W | Power used for LTL deposition. |
| LTL Final Thickness | 1 | mm | Thickness after polishing. |
| Cladding Scanning Speed | 10 | mm/s | Constant speed for composite cladding. |
| Cladding Powder Feed Rate | 29 | g/min | Constant rate for composite cladding. |
| Fe Content (Cladding Layer, No LTL) | 14.045 | % | High Fe migration at 900 W power. |
| Fe Content (Cladding Layer, With LTL) | 7.089 | % | Reduced Fe migration at 900 W power. |
| Friction Coefficient (1000 W, No LTL) | 0.561 | N/A | Measured using micro tribometer. |
| Friction Coefficient (1000 W, With LTL) | 0.45 | N/A | Significant performance enhancement. |
| Raman Diamond Peak | 1332 | cm-1 | Characteristic peak for intact diamond. |
| Raman Graphite Peak | 1580 | cm-1 | Characteristic peak for graphitized carbon. |
Key Methodologies
Section titled âKey MethodologiesâThe experiment employed a two-step laser cladding process using a continuous fiber laser system (iLAMÂŽ25Fpt-600) on 45 steel substrates.
- Raw Material Preparation:
- IN718 alloy powder and 100 mesh diamond particles were mixed at an 80:20 volume ratio via planetary ball milling (2 h).
- Mixed powder was dried at 120 °C for 24 h to ensure moisture removal.
- Substrate Preparation:
- 45 steel substrates were surface ground and polished to remove rust and contaminants.
- Low-Temperature Layer (LTL) Fabrication:
- Pure IN718 powder was deposited onto the substrate.
- Process Parameters: Laser power 1100 W, scanning speed 10 mm/s, powder feed rate 29 g/min.
- The LTL was subsequently polished to a final thickness of 1 mm.
- Diamond Composite Cladding:
- The diamond-IN718 composite powder was clad onto both bare 45 steel and LTL-coated substrates.
- Process Parameters: Laser power range 600-1000 W, scanning speed 10 mm/s, powder feed rate 29 g/min, overlap rate 40%.
- Characterization and Testing:
- Microstructure: Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to analyze morphology, diamond encapsulation, and Fe distribution.
- Graphitization: Raman spectroscopy (532 nm green laser) was used to quantify diamond integrity (1332 cm-1 peak) and graphitization (1580 cm-1 peak).
- Tribology: Friction and wear tests were conducted using a controlled-atmosphere micro tribometer with stainless steel balls as counterface (Normal load: 200 g, duration: 1 h).
Commercial Applications
Section titled âCommercial ApplicationsâThe successful integration of thermally sensitive diamond particles into metal matrices via laser cladding, while maintaining structural integrity and enhancing wear resistance, is critical for several high-tech industrial sectors.
- Advanced Tool Manufacturing:
- Production of ultra-wear-resistant diamond grinding wheels, drills, and cutting inserts for high-precision machining of aerospace alloys, ceramics, and composites.
- Extreme Environment Applications:
- Tools designed for ultra-high-speed cutting and high-temperature corrosive environments where conventional diamond tools fail due to thermal degradation.
- Oil and Gas/Geothermal Drilling:
- Fabrication of thermally stable polycrystalline diamond compact (PDC) cutters and drill bits with extended service life in deep, hot geological formations.
- Additive Manufacturing (AM) of Composites:
- The LTL strategy provides a robust process control mechanism for incorporating other thermally sensitive reinforcement phases (e.g., certain ceramics or carbon nanotubes) into metal matrix composites via laser powder bed fusion or directed energy deposition.
- Surface Engineering:
- Developing protective, hard-facing coatings for components subjected to severe abrasive and adhesive wear in heavy machinery and industrial processing equipment.
View Original Abstract
To address the graphitization of diamond induced by high temperatures during laser cladding of diamond-reinforced composites, this study proposes a laser cladding method utilizing Inconel 718 (IN718) nickel-based alloy as a transition layer which has a lower melting point than the substrate of 45# steel. And then, in order to analyze the detailed characteristics of the samples, scanning electron microscopy (SEM), EDS, Raman spectral analyzer, super-depth-of-field microscope, and friction tests were used. Experimental study and the test results demonstrate that the IN718 transition layer enhances coating performance through dual mechanisms: firstly, its relatively low melting point (1392 °C) reduces the molten poolâs peak temperature, effectively suppressing thermal-induced graphitization of the diamond; on the other hand, simultaneously it acts as a diffusion barrier to inhibit Fe migration from the substrate and weaken Fe-C interfacial catalytic reactions. Microstructural analysis reveals improved diamond encapsulation and reduced interfacial sintering defects in coatings with the transition layer. Tribological tests confirm that samples with the transition layer L exhibit lower friction coefficients and significantly enhanced wear resistance compared to those without. This study elucidates the synergistic mechanism of the transition layer in thermal management optimization and interfacial reaction suppression, providing an innovative solution to overcome the high-temperature damage bottleneck in laser-clad diamond tools.
Tech Support
Section titled âTech SupportâOriginal Source
Section titled âOriginal SourceâReferences
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