Abstract
Transition metal carbides (TMCs) with an excellent hardness-toughness combination are desirable reinforced phase for engineering alloys. In the present work, the mechanical properties of M7C3, M6C and MC carbides with different compositions in tool steels were evaluated by nano-indentation tests and first-principles calculations. The results show that, among these compounds, MC and M7C3 carbides exhibit the largest hardness and fracture toughness, respectively, while M6C carbides display a good hardness-toughness synergy. The hardness of M6C carbides monotonically declines with increased Mo/W ratios while the fracture toughness firstly rises followed by a slight drop. M6C carbides exhibit an excellent combination of hardness (23.7 GPa) and fracture toughness (2.36 ± 0.06 MPa m1/2) in the case of Mo/W ratios of 0.50–0.63. Interestingly, such hardness-toughness tradeoff is absent in Cr-doped M7C3 carbides; with increased Cr/Fe ratios, both the hardness and fracture toughness firstly rise and then decline. M7C3 carbides exhibit a superior synergy of hardness (22.5 ± 1.5 GPa) and fracture toughness (2.71 ± 0.19 MPa m1/2) as Cr/Fe ratios reach 0.86–0.96, which can be rationalized by optimal constitutions of various chemical bonds in M7C3 carbides as revealed by the first-principles calculations.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
