Numerical Simulation of Temperature Characteristics and Graphitization Mechanism of Diamond in Laser Powder Bed Fusion

Chen, Yongqian; Zhang, Shanghua; Liu, Jialin; Zhang, Wei; Ma, Qingyuan; Wu, Xiwang; Guo, Shirui; Cui, Yinghao; Li, Xiaolei; Zheng, Bo; Cui, Lujun

doi:10.3390/ma16186338

Cited by 2 publications

(1 citation statement)

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“…The presence of the graphite phase may be explained partially by graphitization, but most of its amount can be attributed to the graphite from the mold. From the published data, it is known that the graphitization of the diamond is due to the high temperature accumulated on its surface, which is dependent on media, e.g., 850 °C in air, but in a vacuum, graphitization starts at 1200 °C [ 40 ]. There are reports demonstrating that the diamond exposed to heating for a long time may undergo graphitization in the temperature range of 650–750 °C [ 41 ].…”

Section: Resultsmentioning

confidence: 99%

Enhancement of the Refractory Matrix Diamond-Reinforced Cutting Tool Composite with Zirconia Nano-Additive

Ratov,

Mechnik,

Rucki

et al. 2024

Materials

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This paper presents the results of the experimental research on diamond-reinforced composites with WC–Co matrices enhanced with a ZrO2 additive. The samples were prepared using a modified spark plasma sintering method with a directly applied alternating current. The structure and performance of the basic composite 94 wt.%WC–6 wt.%Co was compared with the ones with ZrO2 added in proportions up to 10 wt.%. It was demonstrated that an increase in zirconia content contributed to the intense refinement of the phase components. The composite 25 wt.%Cdiamond–70.5 wt.%WC–4.5 wt.%Co consisted of a hexagonal WC phase with lattice parameters a = 0.2906 nm and c = 0.2837 nm, a cubic phase (a = 1.1112 nm), hexagonal graphite phase (a = 0.2464 nm, c = 0.6711 nm), as well as diamond grits. After the addition of zirconia nanopowder, the sintered composite contained structural WC and Co3W3C phases, amorphous carbon, tetragonal phase t-ZrO2 (a = 0.36019 nm, c = 0.5174 nm), and diamond grits—these structural changes, after an addition of 6 wt.% ZrO2 contributed to an increase in the fracture toughness by more than 20%, up to KIc = 16.9 ± 0.76 MPa·m0.5, with a negligible decrease in the hardness. Moreover, the composite exhibited an alteration of the destruction mechanism after the addition of zirconia, as well as enhanced forces holding the diamond grits in the matrix.

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Section: Resultsmentioning

confidence: 99%