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Hardness is an important indicator of the wear resistance of tool materials. The study of the effect of hardness on the wear resistance of tool materials has significant practical applications. In this experimental work, a series of polycrystalline cubic boron nitride (PcBN) and diamond (PCD) compacts with different hardness are sintered under high temperature and pressure, and these samples were fashioned into turning tools, used for edge wear testing in the granite turning process. Based on the measurements above, the relationship between hardness and wear resistance in two materials with identical grain sizes (1–2 µm) was examined, and the results reveal a significant positive correlation between the hardness and wear resistance of the two materials. Remarkably, the relationship between hardness and wear resistance in two materials complies with the same type of fitting function. But incredibly, the wear resistance of the two materials exhibits inconsistency as the hardness increases. Specifically, below 40 GPa Vickers hardness, both materials exhibit comparable wear resistance. However, above 40 GPa, the difference in wear resistance between the two materials becomes more pronounced with increasing hardness. At the Vickers hardness of 70 GPa, the abrasion ratio of the PCD is approximately 3.5 times that of the PcBN, and it is anticipated that the disparity between them will continue to expand within the broader range of hardness. Further analysis reveals that the intrinsic hardness of the crystal grains significantly impacts the wear resistance of polycrystalline materials. [ABSTRACT FROM AUTHOR]

Polycrystalline diamond composites (PDC) have been used as a cutting material in a multitude of fields, from mechanical processing to oil and gas drilling. In this study, PDC samples were prepared under high pressure and high temperature (HPHT) conditions within a pressure interval of 5.5 to 10.5 GPa by sintering diamond powder (average grain size ~3 μm) with WC-10 wt% Co substrate. Samples obtained with varying sintering pressures and temperatures were characterized using Vickers hardness tester, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results revealed that: (1) within a specified material system, each distinct sintering pressure condition corresponds to a unique optimal sintering temperature that yields the pinnacle of consolidation efficiency in samples. This optimal temperature exhibits a linearly increasing trend with rising sintering pressure; (2) at the intersection where the sintering pressure attains its optimal match with temperature, an increase in pressure fosters more intimate contact and stronger inter-grain bonding among diamond particles, thus amplifying the D D bond formation effect, which consequently leads to a linear enhancement in the Vickers hardness values of PDC with increasing sintering pressure; (3) simultaneously, under conditions of optimal temperature matching, elevating the sintering pressure notably decreases the cobalt content within the polycrystalline diamond layer of PDC samples. These findings furnish crucial experimental evidence for optimizing PDC material properties, significantly contributing to the advancement of both theoretical exploration and technological innovation within the field, carrying profound academic value and practical guidance implications. [Display omitted] • At a given pressure, there is an optimal temperature for the peak sintering performance of PDC. • The optimal sintering temperature exhibits a linear increase with rising pressure. • Under optimal temperature conditions, increased pressure improves sample performance. [ABSTRACT FROM AUTHOR]