類金剛石薄膜在水環(huán)境中的磨損行為研究
發(fā)布時間：2018-08-23 15:37
【摘要】：類金剛石(DLC)薄膜具有優(yōu)異的力學性能和生物相容性,是潛在的人工關節(jié)表面改性材料。在體外實驗中,DLC薄膜可以提高人工關節(jié)的耐磨性和耐腐蝕性,減少人工關節(jié)的磨損和金屬離子的釋放。但是臨床應用過程中,DLC改性后的人工關節(jié)存在薄膜結合失效的問題。DLC薄膜的種類繁多,不同種類的DLC薄膜具有不同的物理化學性質。在體內環(huán)境中服役時,DLC薄膜的磨損與失效機制要受到體液介質的影響。為了研究不同成分、結構的DLC薄膜在人體內摩擦磨損以及失效機制,探索適用于體液介質中服役的DLC薄膜種類以及薄膜/基體組合。本論文以純水以及無機鹽溶液為實驗介質,研究了DLC薄膜成分結構、薄膜/基體界面狀態(tài)、對磨副等因素對DLC磨損失效行為的影響,探討了氮離子注入(氮化)和DLC薄膜沉積復合處理工藝應用于CoCrMo合金金屬人工關節(jié)表面改性的可行性。(1)研究了成分、結構對DLC薄膜在水環(huán)境下摩擦磨損行為的影響。研究結果表明DLC薄膜在水環(huán)境下與Al_2O_3對磨時,含氫DLC薄膜中的H元素會與碳原子成鍵,抑制摩擦化學反應,在純水中摩擦時薄膜表面存在著大量的-CH官能團,-CH官能團與水分子之間存在范德華力作用,所以含氫DLC薄膜在純水中的摩擦和磨損較低。不含氫DLC薄膜在水環(huán)境中摩擦時,由于劇烈的摩擦化學反應,在摩擦表面生成較多含氧(-COH)官能團,這些含氧官能團與水分子之間存在氫鍵作用,故不含氫DLC薄膜在純水中摩擦時產生較高的摩擦和磨損。DLC薄膜的結構也對耐磨性有著重要的影響,含氫DLC薄膜中的飽和的-CH結構由于飽和鍵的穩(wěn)定性在摩擦中不容易發(fā)生轉變,而不飽和的-CH結構由于不飽和鍵的不穩(wěn)定性在摩擦過程中容易發(fā)生石墨化的轉變,從而造成結構的軟化和磨損的加劇。與空氣環(huán)境相比,水環(huán)境可以抑制含氫DLC薄膜的磨損,而促進不含氫DLC薄膜的磨損。(2)研究了薄膜/基體界面化學狀態(tài)對DLC薄膜結合失效的影響。研究結果表明,含氫DLC薄膜在水中服役時發(fā)生結合失效的原因與膜基界面處的氫元素有關,氫元素能夠抑制Cr元素的鈍化,降低界面的化學穩(wěn)定性,使界面容易被腐蝕而產生裂紋源,從而導致薄膜的早期結合失效。進一步研究表明,在不同基體表面制備的DLC薄膜具有類似的結構。當不同基體材料表面粗糙度相差不大時,同種工藝制備的DLC薄膜的結合力主要與膜/基界面處的化學狀態(tài)有關。Ti6A14V基體中含有Ti、V等強碳化物形成元素,可以在膜/基界面處與DLC薄膜形成良好的化學結合,所以Ti6A14V/DLC具有最好的膜基結合力。316L不銹鋼中的Fe元素碳化物形成能力較弱,在界面處與DLC薄膜之間的化學鍵和能力較弱,所以膜基結合力也較弱。不同基體表面DLC薄膜在鹽溶液中的磨損失效形式為結合失效,所以具有最強結合力的Ti6A14V/DLC具有最好的耐磨性,而具有最差結合力的316L/DLC具有最差的耐磨性。基體材料的耐腐蝕性直接決定著DLC膜基體系的長期穩(wěn)定性。Ti6A14V基體因為具有較高的耐腐蝕性,其表面的DLC薄膜也具有最好的長期穩(wěn)定性,316L不銹鋼因具有較差的耐腐蝕性,其表面的DLC薄膜長期穩(wěn)定性也較差。(3)研究了對磨副材料對不含氫DLC薄膜在空氣和純水介質中摩擦磨損的影響。研究結果表明,CoCrMo對磨副在空氣中與不含氫DLC摩擦時,由于形成脆性的、含金屬氧化物的轉移膜,降低了自潤滑作用,增加了與DLC之間的粘著,導致較高的摩擦和磨損。在水中摩擦磨損時,水環(huán)境會抑制CoCrMo表面含金屬氧化物轉移膜的形成并阻止金屬對磨副與DLC薄膜的粘著,利于在對磨副表面形成無序石墨結構的粘附物質,降低DLC的摩擦和磨損。對于A1203對磨副,在空氣中由于低的粘著和固體潤滑,造成的DLC磨損較少。而在水環(huán)境中由于難以實現(xiàn)固體潤滑,故硬質的A1203會造成較高的DLC磨損。(4)研究了氮離子注入(氮化)和DLC薄膜沉積復合處理工藝應用于CoCrMo合金金屬人工關節(jié)表面改性的可行性。研究結果表明氮離子注入(氮化)和DLC薄膜沉積復合處理工藝成功的提高了CoCrMo合金的力學性能和耐磨性,但是氮元素在注入CoCrMo基體后,會促進Co離子的釋放,抑制Cr元素的鈍化能力,從降低基體的腐蝕穩(wěn)定性。在長時間的服役過程中,由于注氮層的緩慢腐蝕溶解,DLC薄膜的結合力發(fā)生了明顯的弱化。所以在對人體內植入金屬器械的表面改性中,注氮工藝應該被慎重采用。
[Abstract]:Diamond-like carbon (DLC) film is a potential surface modification material for artificial joints because of its excellent mechanical properties and biocompatibility. In vitro, DLC film can improve the wear resistance and corrosion resistance of artificial joints, reduce the wear and metal ion release of artificial joints. However, in the clinical application, the artificial joints modified by DLC film can be used to improve the wear resistance and corrosion resistance of artificial joints. There are many kinds of DLC films, and different kinds of DLC films have different physical and chemical properties. The wear and failure mechanisms of DLC films in vivo are affected by humoral media. In order to study the friction and wear and failure mechanism of DLC films with different composition and structure in vivo, the wear and failure mechanisms of DLC films are studied. In this paper, the composition and structure of DLC film, the interface state of DLC film and substrate, the effect of grinding pairs and other factors on the wear failure behavior of DLC film were studied in pure water and inorganic salt solution. Feasibility of surface modification of CoCrMo alloy artificial joints by the treatment process was studied. (1) The effects of composition and structure on the friction and wear behavior of DLC films in water environment were studied. There are a lot of - CH functional groups on the surface of DLC films when they are rubbed in water. There is Van der Waals force between - CH functional groups and water molecules, so the friction and wear of DLC films containing hydrogen are low in pure water. These oxygen-containing functional groups have hydrogen bonds with water molecules, so the hydrogen-free DLC films have higher friction and wear resistance when they are rubbed in pure water. The structure of DLC films also has an important impact on the wear resistance. The saturated-CH structure of hydrogen-containing DLC films is not easy to change due to the stability of the saturated bonds, but not saturated. Unsaturated bond instability of H-CH structure is easy to occur graphitization transformation during friction process, resulting in structural softening and wear intensification. Compared with air environment, water environment can inhibit the wear of hydrogen-containing DLC films, and promote the wear of hydrogen-free DLC films. (2) The effect of chemical state of film/substrate interface on DLC thin film was studied. The results show that the reason of bonding failure of DLC thin films containing hydrogen in water is related to the hydrogen element at the interface between the film and substrate. Hydrogen element can inhibit the passivation of Cr element, reduce the chemical stability of the interface, make the interface easy to be corroded and produce crack source, which leads to the early bonding failure of DLC thin films. One step study shows that DLC films prepared on different substrates have similar structures. When the surface roughness of different substrates is not different, the adhesion of DLC films prepared by the same process is mainly related to the chemical state at the film/substrate interface. Ti6A14V / DLC has the best adhesion with DLC film because of the good chemical bonding between the film and the substrate. The Fe carbide formation ability of 316L stainless steel is weak, and the chemical bonding and ability between the interface and DLC film are weak, so the adhesion between the film and the substrate is weak. Ti6A14V/DLC with the strongest bonding strength has the best wear resistance, while 316L/DLC with the lowest bonding strength has the worst wear resistance. Corrosion resistance of matrix materials directly determines the long-term stability of DLC matrix system. Ti6A14V matrix has the highest corrosion resistance, and the DLC film on its surface also has the highest wear resistance. Good long-term stability, 316L stainless steel because of its poor corrosion resistance, the long-term stability of DLC film on its surface is also poor. (3) The effect of pair material on the friction and wear of hydrogen-free DLC film in air and pure water medium was studied. The water environment will inhibit the formation of metal oxide transfer film on the surface of CoCrMo and prevent the adhesion between metal pair and DLC film, which is beneficial to the formation of disordered stone on the surface of the pair. For A1203 pairs, the wear of DLC is less due to low adhesion and solid lubrication in the air. But in the water environment, hard A1203 will cause higher wear of DLC because it is difficult to achieve solid lubrication. The results show that the mechanical properties and wear resistance of CoCrMo alloy can be improved by nitrogen ion implantation (nitriding) and DLC film deposition. However, nitrogen element can promote the release of Co ions and inhibit the passivation of Cr element after implanting into the matrix of CoCrMo alloy. In order to reduce the corrosion stability of the substrate, the bonding strength of DLC film is weakened obviously due to the slow corrosion and dissolution of the nitrogen-injected layer during the long-term service.
【學位授予單位】：西南交通大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TB383.2;R318.08
本文編號：2199505
[Abstract]:Diamond-like carbon (DLC) film is a potential surface modification material for artificial joints because of its excellent mechanical properties and biocompatibility. In vitro, DLC film can improve the wear resistance and corrosion resistance of artificial joints, reduce the wear and metal ion release of artificial joints. However, in the clinical application, the artificial joints modified by DLC film can be used to improve the wear resistance and corrosion resistance of artificial joints. There are many kinds of DLC films, and different kinds of DLC films have different physical and chemical properties. The wear and failure mechanisms of DLC films in vivo are affected by humoral media. In order to study the friction and wear and failure mechanism of DLC films with different composition and structure in vivo, the wear and failure mechanisms of DLC films are studied. In this paper, the composition and structure of DLC film, the interface state of DLC film and substrate, the effect of grinding pairs and other factors on the wear failure behavior of DLC film were studied in pure water and inorganic salt solution. Feasibility of surface modification of CoCrMo alloy artificial joints by the treatment process was studied. (1) The effects of composition and structure on the friction and wear behavior of DLC films in water environment were studied. There are a lot of - CH functional groups on the surface of DLC films when they are rubbed in water. There is Van der Waals force between - CH functional groups and water molecules, so the friction and wear of DLC films containing hydrogen are low in pure water. These oxygen-containing functional groups have hydrogen bonds with water molecules, so the hydrogen-free DLC films have higher friction and wear resistance when they are rubbed in pure water. The structure of DLC films also has an important impact on the wear resistance. The saturated-CH structure of hydrogen-containing DLC films is not easy to change due to the stability of the saturated bonds, but not saturated. Unsaturated bond instability of H-CH structure is easy to occur graphitization transformation during friction process, resulting in structural softening and wear intensification. Compared with air environment, water environment can inhibit the wear of hydrogen-containing DLC films, and promote the wear of hydrogen-free DLC films. (2) The effect of chemical state of film/substrate interface on DLC thin film was studied. The results show that the reason of bonding failure of DLC thin films containing hydrogen in water is related to the hydrogen element at the interface between the film and substrate. Hydrogen element can inhibit the passivation of Cr element, reduce the chemical stability of the interface, make the interface easy to be corroded and produce crack source, which leads to the early bonding failure of DLC thin films. One step study shows that DLC films prepared on different substrates have similar structures. When the surface roughness of different substrates is not different, the adhesion of DLC films prepared by the same process is mainly related to the chemical state at the film/substrate interface. Ti6A14V / DLC has the best adhesion with DLC film because of the good chemical bonding between the film and the substrate. The Fe carbide formation ability of 316L stainless steel is weak, and the chemical bonding and ability between the interface and DLC film are weak, so the adhesion between the film and the substrate is weak. Ti6A14V/DLC with the strongest bonding strength has the best wear resistance, while 316L/DLC with the lowest bonding strength has the worst wear resistance. Corrosion resistance of matrix materials directly determines the long-term stability of DLC matrix system. Ti6A14V matrix has the highest corrosion resistance, and the DLC film on its surface also has the highest wear resistance. Good long-term stability, 316L stainless steel because of its poor corrosion resistance, the long-term stability of DLC film on its surface is also poor. (3) The effect of pair material on the friction and wear of hydrogen-free DLC film in air and pure water medium was studied. The water environment will inhibit the formation of metal oxide transfer film on the surface of CoCrMo and prevent the adhesion between metal pair and DLC film, which is beneficial to the formation of disordered stone on the surface of the pair. For A1203 pairs, the wear of DLC is less due to low adhesion and solid lubrication in the air. But in the water environment, hard A1203 will cause higher wear of DLC because it is difficult to achieve solid lubrication. The results show that the mechanical properties and wear resistance of CoCrMo alloy can be improved by nitrogen ion implantation (nitriding) and DLC film deposition. However, nitrogen element can promote the release of Co ions and inhibit the passivation of Cr element after implanting into the matrix of CoCrMo alloy. In order to reduce the corrosion stability of the substrate, the bonding strength of DLC film is weakened obviously due to the slow corrosion and dissolution of the nitrogen-injected layer during the long-term service.
【學位授予單位】：西南交通大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TB383.2;R318.08
【參考文獻】
相關期刊論文 前1條
1 劉亞軍;池迎春;;國產人工關節(jié)產品新進展[J];中國醫(yī)療設備;2015年10期
相關碩士學位論文 前1條
1 裴亞楠;超高分子量聚乙烯表面沉積類金剛石薄膜改善耐磨性研究[D];西南交通大學;2012年
，本文編號：2199505
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