Abstract
Cr–Ni coatings with the mass ratios of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% Ni were fabricated on H13 hot work mould steel using a laser cladding (LC). The surface–interface morphologies, chemical elements, surface roughness and phase composition of the obtained Cr–Ni coatings were analysed using a scanning electron microscope (SEM), energy disperse spectroscopy (EDS), atomic force microscope (AFM) and X–ray diffractometer (XRD), respectively. The friction–wear properties and wear rates of Cr–Ni coatings with the different mass ratios of Cr and Ni at 600 °C were investigated, and the worn morphologies and wear mechanism of Cr–Ni coatings were analysed. The results show that the phases of Cr–Ni coatings with mass ratios of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% Ni are composed of Cr + Ni single-phases and their compounds at the different stoichiometry, the porosities on the Cr–Ni coatings increase with the Cr content increasing. The average coefficient of friction (COF) of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% coatings are 1.10, 0.33 and 0.87, respectively, in which the average COF of 20% Cr–80% Ni coating is the lowest, exhibiting the better anti-friction performance. The wear rate of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% Ni coatings is 4.533 × 10−6, 5.433 × 10−6, and 1.761 × 10−6 N−1·s−1, respectively, showing the wear resistance of Cr–Ni coatings at a high temperature increases with the Cr content, in which the wear rate is 24% Cr–76% Ni coating with the better reducing wear. The wear mechanism of 17% Cr–83% Ni and 20% Cr–80% Ni and 24% Cr–76% coatings at 600 °C is primarily adhesive wear, and that of 24% Cr–76% coating is also accompanied by oxidative wear.
Highlights
As a hot work mould steel, H13 steel (4Cr5MoSiV1) with high wear resistance, thermal stability and fatigue resistance, etc. [1] is widely used on hot forging, hot extrusion and hot casting mould manufacturing [2], of which comprehensive mechanical properties are well at medium temperature of~550 ◦ C [3]
When the above oxides were formed, the debris was generated on the worn track, causing the coatings the oxidation reaction occurred at 600 ◦ C, resulting in the oxides of NiO and Cr2 O3 [21,22], i.e., coefficient of friction (COF) of Cr–Ni coatings to oscillate [23]
Trackswere formed, the Stable theof above debrisperiod was generated on the worn track, causing the COFsThe of Cr–Ni coatings to oscillate
Summary
As a hot work mould steel, H13 steel (4Cr5MoSiV1) with high wear resistance, thermal stability and fatigue resistance, etc. [1] is widely used on hot forging, hot extrusion and hot casting mould manufacturing [2], of which comprehensive mechanical properties are well at medium temperature of. The mould surface will have wear failure, thermal fatigue cracking and other failures [1], due to strong friction and mechanical impact at high temperature [2]. Laser cladding improves the bonding strength between the coating and the substrate comparing to thermal spraying and reduces the loss of the coating during wear [9]. Zhang et al [16] analysed the oxidation resistance of Ni–Cr nano-composite films at high temperature. The above Cr–Ni coatings were fabricated using an electro-deposition; there were few reports on the friction-wear properties of laser cladded Cr–Ni coatings with the different mass ratios of Cr and Ni at high temperature. The effects of mass ratios of Cr and Ni on high temperature friction-wear performances of laser-cladded Cr–Ni coating were discussed, and the mechanism of.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
