Chromium-plated diamond/copper composite materials, with Cr layer thicknesses of 150 nm and 200 nm, were synthesized using a vacuum hot-press sintering process. Comparative analysis revealed that the thermal conductivity of the composite material with a Cr layer thickness of 150 nm increased by 266%, while that with a Cr layer thickness of 200 nm increased by 242%, relative to the diamond/copper composite materials without Cr plating. This indicates that the introduction of the Cr layer significantly enhanced the thermal conductivity of the composite material. The thermal properties of the composite material initially increased and subsequently decreased with rising sintering temperature. At a sintering temperature of 1050 °C and a diamond particle size of 210 μm, the thermal conductivity of the chromium-plated diamond/copper composite material reached a maximum value of 593.67 W∙m⁻¹∙K⁻¹. This high thermal conductivity is attributed to the formation of chromium carbide at the interface. Additionally, the surface of the diamond particles in contact with the carbide layer exhibited a continuous serrated morphology due to the interface reaction. This “pinning effect” at the interface strengthened the bonding between the diamond particles and the copper matrix, thereby enhancing the overall thermal conductivity of the composite material.

The journal retracts the article titled “Cr–Diamond/Cu Composites with High Thermal Conductivity Fabricated by Vacuum Hot Pressing”

In order to enhance the quality of diamond composite materials, this work employs a Cu-Co-Fe and Ni-Cr-Cu pre-alloyed powder mixture as a transition layer, and utilizes laser-welding technology for saw blade fabrication. By adjusting the laser-welding process parameters, including welding speed and welding power, well-formed welded joints were achieved, and the microstructure and mechanical properties of the welded joints were investigated. The results demonstrate that the best welding performance was achieved at a laser power of 1600 W and a welding speed of 1400 mm/min, with a remarkable tooth engagement strength of up to 819 MPa. The fusion zone can be divided into rich Cu phase and rich Fe phase regions, characterized by coarse grains without apparent preferred orientation. The microstructure of the heat-affected zone primarily consists of high-hardness brittle quenched needle-like martensite, exhibiting a sharp increase in microhardness up to 550 HV. Fracture occurred at the boundary between the fusion zone and the heat-affected zone of the base material, where stress concentration was observed. By adjusting the welding parameters and transition layer materials, the mechanical properties of the joints were improved, thereby achieving a reliable connection between diamond composite materials and the metal substrate.

The development and application of laser welding transition layer technology is pivotal for manufacturing high-performance diamond saw blades. Despite its importance, there is a need for more precise modeling to optimize welding parameters and enhance blade performance. This study employs SYSWELD software to simulate the laser welding process, demonstrating high accuracy in predicting the molten pool shape. A cross-scale multi-field coupling model was established using the finite element method, incorporating temperature field, phase transformation, grain morphology, stress field, and fatigue performance. A comprehensive life cycle assessment identified optimal welding parameters. The results indicate that a laser welding speed of 26 mm/s and a power of 1700 W minimize weld stress, reduce the digital volume correlation (DVC) value, and enhance fatigue resistance. Additionally, welding tests confirmed that using 1700 W produced the highest tooth strength of 1200 MPa, validating the simulation results. This study addresses existing gaps in modeling accuracy and parameter optimization, offering a robust framework for improving the performance and reliability of laser-welded diamond saw blades.