This surface has extreme hardness (60 RC. ), excellent wear and corrosion resistance, and low coefficientof friction.
这表面有极高的硬度（60局。），耐磨性和耐腐蚀性，低摩擦系数。
2
Moreover, the variation law of mold surface hardness and interface heat transfer coefficient were studied.
另外，研究了消失模铸造法铸型表面硬度、界面换热系数的变化规律。
3
It shows that the composites' tensile strength and elongation decrease while the hardness and friction coefficient increase with the addition content of graphite.