Abstract：
Cobalt-Chromium (CoCr) alloys are currently used for various cardiovascular, orthopedic, fracture fixation, and dental implants. A variety of processes such as casting, forging, wrought processing, hot isostatic pressing, metal injection molding, milling, selective laser melting, and electron beam melting are used in the manufacture of CoCr alloy implants. The microstructure and precipitates (carbides, nitrides, carbonitrides, and intermetallic compounds) formed within the alloy are primarily determined by the type of manufacturing process employed. Although the effects of microstructure and precipitates on the physical and mechanical properties of CoCr alloys are well reviewed and documented in the literature, the effects on corrosion resistance and biocompatibility are not comprehensively reviewed. This article reviews the various processes used to manufacture CoCr alloy implants and discusses the effects of manufacturing processes on corrosion resistance and biocompatibility. This review concludes that the microstructure and precipitates formed in the alloy are unique to the manufacturing process employed and have a significant impact on the corrosion resistance and biocompatibility of CoCr alloys. Additionally, a historical and scientific overview of corrosion and biocompatibility for metallic implants is included in this review. Specifically, the failure of CoCr alloys when used in metal-on-metal bearing surfaces of total hip replacements is highlighted. It is recommended that the type of implant/application (orthopedic, dental, cardiovascular, etc.) should be the first and foremost factor to be considered when selecting biomaterials for medical device development.
摘要：
钴铬（CoCr）合金目前用于各种心血管，骨科,骨折固定术,和牙科植入物。各种工艺，如铸造，锻造,锻造加工，热等静压，金属注塑成型，铣削,选择性激光熔化,和电子束熔化用于制造CoCr合金植入物。微观结构和沉淀物(碳化物，氮化物，碳氮化物,和金属间化合物）在合金内形成的主要由所采用的制造工艺类型决定。尽管显微组织和析出物对CoCr合金的物理和机械性能的影响在文献中得到了很好的回顾和记录，对耐腐蚀性和生物相容性的影响没有全面审查。本文回顾了用于制造CoCr合金植入物的各种工艺，并讨论了制造工艺对耐腐蚀性和生物相容性的影响。这篇综述得出的结论是，在合金中形成的微观结构和析出物是所采用的制造工艺所独有的，并且对CoCr合金的耐腐蚀性和生物相容性有重大影响。此外,本综述包括金属植入物的腐蚀和生物相容性的历史和科学概述。具体来说,强调了CoCr合金在全髋关节置换术的金属对金属轴承表面中使用时的失效。建议植入物/应用的类型(骨科，牙科,心血管,等。）应该是选择用于医疗器械开发的生物材料时要考虑的首要因素。
