A comparison of the tribo-mechanical properties of a wear resistant cobalt-based alloy produced by different manufacturing processes
A comparison of the tribo-mechanical properties of a wear resistant cobalt-based alloy produced by different manufacturing processes
复制标题
不同制造工艺生产的耐磨钴基合金的摩擦机械性能比较
DOI：
10.1115/1.2736450
复制
发表时间：
2006
影响因子：
2.5
通讯作者：
H. Lovelock
中科院分区：
文献类型：
--
作者：
H. Yu;R. Ahmed;H. Lovelock
本文旨在比较通过两种不同制造路线（即砂铸和热等静压粉末固结（HIPing））生产的耐磨钴基合金的摩擦机械性能和结构-性能关系。该合金具有Co-33 Cr-17.5W-2.5C的标称重量%组成，其类似于市售Stellite 20合金的组成。高钨和碳含量提供了严重的耐磨性和滑动磨损。然而，铸造合金的粗碳化物结构也会导致脆性，因此进行本研究以了解将加工路线改为HIP所引起的碳化物细化和金属基体的相应变化是否可以在该合金的摩擦机械性能中提供额外的优点。热等静压（HIP）合金具有比铸造合金更精细的显微组织。两种合金具有相似的硬度，但HIP合金的抗冲击性高得多。尽管这两种合金的耐磨性相似，但由于碳化物形态不同，其主要磨损机制不同。碳化物的脆性断裂和犁削是铸造合金的主要磨损机制，而犁削和碳化物拔出是热等静压合金的主要磨损机制。热等静压处理后的合金在接触疲劳性能方面表现出显著的改善，表明其具有上级的抗冲击性和抗疲劳性，而不影响硬度和抗滑动/磨粒磨损性，使其适用于相对较高应力的应用。
This paper aims to compare the tribo-mechanical properties and the structure-property relationships of a wear resistant cobalt-based alloy produced via two different manufacturing routes, namely sand casting and powder consolidation by Hot Isostatic Pressing (HIPing). The alloy had a nominal wt% composition of Co-33Cr-17.5W-2.5C, which is similar to the composition of commercially available Stellite 20 alloy. The high tungsten and carbon contents provide resistance to severe abrasive and sliding wear. However, the coarse carbide structure of the cast alloy also gives rise to brittleness, and hence this research was conducted to comprehend if the carbide refinement and corresponding changes in the metal matrix caused by changing the processing route to HIPing can provide additional merits in the tribo-mechanical performance of this alloy. The Hot Isostatic Pressed (HIPed) alloy possessed a much finer microstructure than the cast alloy. Both alloys had similar hardness, but the impact resistance of the HIPed alloy was much higher. Despite similar abrasive and sliding wear resistance for both alloys, their main wear mechanisms were different due to their different carbide morphologies. Brittle fracture of the carbides and ploughing of the matrix were the main wear mechanisms for the cast alloy, whereas ploughing and carbide pullout were the dominant wear mechanisms for the HIPed alloy. The HIPed alloy showed significant improvement in contact fatigue performance, indicating its superior impact and fatigue resistance without compromising the hardness and sliding/abrasive wear resistance, making it suitable for relatively higher stress applications.Copyright © 2006 by ASME