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外科移植人工髋关节的使用寿命可以提高400倍以上。据橡树岭国立实验室和伯明翰市阿拉巴马大学的科学家报道,在一种重量轻的钛合金表面上,采用离子注人形成氮原子薄膜,由此种材料制成的人工关节球,具有耐磨性和抗体液腐蚀性,注 入氮的表面最大限度地减少了金属粒子的释放,从而避免了替代关节产生的令人痛苦的组织炎症。美国每年约有7500人按装人工髋关节,即可以在聚乙烯臼槽内转动的金属合金球,像天然关节那样使大腿转动。但是在行走运动时保护金属表面的氧化物逐渐剥离,使人体体液直接腐蚀。这样裸露的金属不但把不需要的金属离子引进到肌体内,并且使氧化物粒子嵌入聚乙烯臼槽内,在那里将进一步擦划球体产生更多的金属碎片。 离子注入法是几种表面改性技术中的一种,现正应用于材料科学研究,以解决上述问题。在合金表面建立保护膜,增强表面强度,降低对磨损和腐蚀的敏感性。此工艺将具有所需要特性的单个原子,采用加速过程轰击和渗透到材料的表面。一旦注入了这些掺杂原子,就会改变表面的原子结构,并改善电学、化学、机械,光学和耐蚀性能。离子注入只能改变该合金表面几个原子层的结构。对髋关节来说,尤其重要的性能是体强度,重量,耐蚀性和疲劳强度。因为少数合金既具有体性能又具有表面性能。离子?
Surgical graft artificial hip joint life can be increased more than 400 times. According to scientists at Oak Ridge National Laboratory and the University of Alabama in Birmingham, on a lightweight titanium alloy surface, an artificial implant is made of ion-implanted thin films of nitrogen atoms, Abrasion and fluid corrosivity, nitrogen-infused surfaces minimize the release of metal particles, thus avoiding the painful tissue inflammation that can be caused by an alternative joint. Every year, about 7,500 people in the United States wear artificial hip joints, that is, metal alloy balls that can rotate in a polyethylene mortar slot to make the thighs turn like a natural joint. However, walking in the protection of metal surface oxide gradually stripped, so that human body fluids directly corroded. This bare metal not only introduced unwanted metal ions into the body, but also embedded the oxide particles in the polyethylene mortar slot, where it would further scrape the spheres to produce more metal fragments. Ion implantation is one of several surface modification techniques and is being applied to material science research to solve the above problems. A protective film is formed on the alloy surface to enhance the surface strength and reduce the sensitivity to wear and corrosion. This process will have the required characteristics of a single atom, the use of accelerated bombardment and penetration of the surface of the material. Once these dopant atoms are implanted, they alter the atomic structure of the surface and improve electrical, chemical, mechanical, optical, and corrosion resistance. Ion implantation can only change the structure of several atomic layers on the surface of the alloy. Of particular importance to the hip joint are body strength, weight, corrosion resistance and fatigue strength. Because a small number of alloys have both body properties and surface properties. ion?