Table 1. Information on different surface coatings and their corresponding tribological behaviors.

Coating material	Hardness	COF	Wear rate or friction loss	Test conditions	Ref.
WC-Ni	1053.5 HV0.2	0.2759	2.2 mg	20 N, 400 rpm, 60 min, Si3N4 balls	35
Ni-G	6.85 ± 0.51 GPa	0.17	1.94 × 10−3 mm3 N−1 m−1	52 MPa, 100 rpm, 3.14 mm2, 24 °C, 1 Cr15Ni4Mo3N steel	44
Ni–MoS2	7.41 ± 0.73 GPa	0.61	2.58 × 10−3 mm3 N−1 m−1
Cu–Sn	2.74 ± 0.27 GPa	0.61	0.62 × 10−3 mm3 N−1 m−1
MoS2/Ti–MoS2/Si	7.53 GPa	0.0432	3.2 × 10−7 mm3 N−1 m−1	8 N, relative humidity 45%, 20 °C, 5 Hz, amplitude: 5 mm, the loop count is 10 000 times, GCr15 steel balls	50
Cr3C2–NiCr (95/5)%	1065 HV0.1kg	—	4.4 × 10−7 mg g−1	3 kg, 650 °C, impact angle: 75°, particle velocity: 80 m s−1, Al2O3 particles, feed rate: 5 g min−1, 10 min	64
Cr3C2–NiCr (90/10)%	875.33 HV0.1kg	—	3.2 × 10−7 mg g−1
Cr3C2–NiCr (85/15)%	621.33 HV0.1kg	—	2.8 × 10−7 mg g−1
Al2O3–40ZrO2	900 HV0.3	0.03–0.04	0.07 mm3 m−1	5 kg, 100 N cm−2, contact area: 16 mm2, mineral oil	66
ZrO2–MgO	777 HV0.3	0.155–0.190	—
AlCrN–TiAlN	33.0 ± 8.5 GPa	0.2	—	Cutting speed: 160 m min−1, feed rate: 15 275 mm min−1, cutting depth: 0.3 mm, cutting width: 4 mm	54
Ti3C2/MXene	—	0.0067 ± 0.0017	4.9 × 10−7 mm3 (N−1 m−1)	2 N, 0.1 m s−1, 1 h, dew point temperature: −40 °C, relative humidity: 0.1%, indoor temperature, nitrogen atmosphere	37
Ti3C2/graphene	—	0.0042 ± 0.0011	4.5 × 10−9 mm3 (N−1 m−1)