论文标题
WC硬质具有铁基粘合剂的蠕变变形
Creep deformation of WC hardmetals with iron-based binders
论文作者
论文摘要
由于其成本较低和毒性，铁是替代WC硬质钴的候选者。在900-1200°C下测试了WC-FECR硬质量。在同育治疗过程中，特别注意稳态蠕变率和应激量表（N）。观察到了三种压力依赖性。以前，在中等应力下，以前有两个用于WC-CO：Power Law Creep（n〜3）；晶界滑动（n〜1）在较高的应力下，通常> 100mpa。还观察到了先前未报告的低应力（<10MPa）制度，指数为n〜2。通过将电子显微镜与X射线衍射纹理测量相结合，低应力状态归因于粘合剂的粘性流，该粘合剂通过WC骨架中的扩散蠕变可容纳。该机制可能适用于其他硬质。与类似的WC-CO材料相比，WC-FECR显示出低于1000°C以下的蠕变耐药性，可以通过其较低的自扩张性来解释，而WC的溶解度低于CO。但是，在与液态综合性形成（约1140°C）相对应的温度下，其蠕变耐药性下降了。这些结果表明，如果不超过共晶温度，则FECR可能是CO的合适替代品。
Iron is a candidate to replace cobalt in WC hardmetals, due to its lower cost and toxicity. A WC-FeCr hardmetal was compression tested at 900-1200 °C. Particular attention is paid to the steady-state creep rates and stress-exponents (n) during isostress treatments. Three regimes of stress dependence are observed. Two of these were previously reported for WC-Co: power law creep (n~3) at medium stresses; and grain boundary sliding (n~1) at higher stresses, generally >100MPa. A previously unreported low stress (<10MPa) regime with an exponent of n~2 is also observed. By combining electron microscopy with X-ray diffraction texture measurements, the low stress regime is attributed to viscous flow of the binder, which is accommodated by diffusional creep in the WC skeleton. The mechanism may be applicable to other hardmetals. Compared to analogous WC-Co materials, WC-FeCr shows improved creep resistance below 1000 °C, which can be explained by its lower self-diffusivity, and a lower solubility for WC than Co. However, at temperatures corresponding to liquid eutectic formation (~1140 °C), its creep resistance becomes inferior. These results indicate FeCr may be a suitable replacement for Co provided the eutectic temperature is not exceeded.
