[求助] 弹性模量与硬度有什么关系？

Although diamond, with the highest known hardness (70 to 100 GPa), has traditionally been used to fulfill many of these needs, there are limits to its applicability. For example, diamond is not used to cut steel and other ferrous metals because of the detrimental formation of iron carbide during high-speed machining. Therefore, there is a need for synthetic materials that can be used in place of diamond. Cubic boron nitride (BN), the second hardest material (45 to 50 GPa), is used to cut steel because iron borides and nitrides are much less stable.