多孔NiTi形状记忆合金的高温氧化和化学氧化表面改性研究
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摘要
本论文对多孔NiTi形状记忆合金进行了高温氧化、化学氧化以及化学氧化与后续高温氧化相结合的表面改性研究,采用扫描电子显微镜(SEM)、能谱分析(EDS)及X射线衍射(XRD)等分析方法系统研究了表面改性后多孔NiTi记忆合金的表面组织结构特征,并将表面改性后的多孔NiTi记忆合金在生理盐水(0.9%NaCl)中进行浸泡(悬挂)和电化学腐蚀试验,表征了其耐蚀性能的变化和Ni离子释出行为。
研究结果表明,高温氧化温度升高时多孔NiTi记忆合金表面膜经历了由低结晶度Ti的过渡氧化物向锐钛矿型TiO2相的转变,同时膜层中Ni含量逐渐下降。但获得锐钛矿型TiO2相的同时,过高的氧化温度(>500 oC)导致了氧化膜内部出现因热应力而产生的微裂纹,并对基体/氧化层界面的结合强度造成不利影响。腐蚀性能的测试结果表明,与氧化层的相结构相比它的均匀、完整性是提高合金耐蚀能力的关键。
经H2O2+HCl溶液体系化学氧化处理后多孔NiTi记忆合金表面生成了以Ti的非晶氧化物为主且相对贫镍的完整氧化层,因而多孔NiTi记忆合金的耐蚀能力明显提高,Ni离子释出速率大幅减小,这对改善合金的生物相容性十分有益。氧化动力学的初步研究表明,化学氧化过程中合金的质量变化即反应过程中的氧化和溶解反应的平衡受到HCl浓度和氧化时间的协同作用。
研究还表明,经过化学氧化处理后的多孔NiTi记忆合金再进行后续高温氧化处理时,在较低温度下(400oC)其表面的非晶氧化物即转变为锐钛矿型TiO2相,虽然后续高温处理仍对氧化层原有的组织结构及基体/氧化层界面的结合强度产生影响,但所获得的锐钛矿型TiO2相将为后续沉积生物活性更高的羟基磷灰石层提供了可能。
In this thesis, surface modification of porous NiTi shape memory alloys were performed through high temperature oxidation, chemical oxidation and the combination of the above two precesses (i.e., the initial chemical oxidation followed by a high temperature treatment). The surface microstructures of the surface-modified porous NiTi alloys were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The Ni ion release behavior and corrosion resistance of the surface-modified porous NiTi alloys immersed in physiological saline and electrochemical solution were evaluated.
The results have shown that the oxide film mainly composed of anatase TiO2 and depleted in Ni formed on porous NiTi surface by high temperature oxidation. The content of anatase TiO2 phase increases with the oxidation temperature. However, an over high temperature (e.g., >500 oC) tends to induce cracking of the surface film caused by internal thermal stress and thus deteriorate the interface strength between the oxide film and NiTi substrate. The results of corrosion resistance tests indicate that the uniformity and integrity of the protective oxide film play a key in improving corrosion resistance of porous NiTi alloy.
After a chemical oxidation in H2O2+HCl solution, the oxide film composed of the amorphous oxide and depleted in Ni formed on porous NiTi surface. The defect-free oxide film can significantly enhance corrosion resistance of the substrate and reduce Ni ion release, thus would greatly improve biocompatibility of porous NiTi alloys. The preliminary study of oxidation kinetics has shown that the mass variation of porous NiTi substrate, determined by the HCl concentration and oxidation time, depends on the balance of the kinetics between the oxidation and dissolution reactions during the chemical oxidation process.
It has been shown that the amorphous titanium oxide formed through chemical oxidation followed by high temperature oxidation. At a relatively low temperature of 400oC, the amorphous titanium oxide changed into crystalline anatase TiO2. Although the follow-up high temperature treatment had an adverse influence on interface strength between the oxide film and NiTi substrate, the anatase TiO2 phase provides the possibility for the deposition of HA.
研究结果表明,高温氧化温度升高时多孔NiTi记忆合金表面膜经历了由低结晶度Ti的过渡氧化物向锐钛矿型TiO2相的转变,同时膜层中Ni含量逐渐下降。但获得锐钛矿型TiO2相的同时,过高的氧化温度(>500 oC)导致了氧化膜内部出现因热应力而产生的微裂纹,并对基体/氧化层界面的结合强度造成不利影响。腐蚀性能的测试结果表明,与氧化层的相结构相比它的均匀、完整性是提高合金耐蚀能力的关键。
经H2O2+HCl溶液体系化学氧化处理后多孔NiTi记忆合金表面生成了以Ti的非晶氧化物为主且相对贫镍的完整氧化层,因而多孔NiTi记忆合金的耐蚀能力明显提高,Ni离子释出速率大幅减小,这对改善合金的生物相容性十分有益。氧化动力学的初步研究表明,化学氧化过程中合金的质量变化即反应过程中的氧化和溶解反应的平衡受到HCl浓度和氧化时间的协同作用。
研究还表明,经过化学氧化处理后的多孔NiTi记忆合金再进行后续高温氧化处理时,在较低温度下(400oC)其表面的非晶氧化物即转变为锐钛矿型TiO2相,虽然后续高温处理仍对氧化层原有的组织结构及基体/氧化层界面的结合强度产生影响,但所获得的锐钛矿型TiO2相将为后续沉积生物活性更高的羟基磷灰石层提供了可能。
In this thesis, surface modification of porous NiTi shape memory alloys were performed through high temperature oxidation, chemical oxidation and the combination of the above two precesses (i.e., the initial chemical oxidation followed by a high temperature treatment). The surface microstructures of the surface-modified porous NiTi alloys were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The Ni ion release behavior and corrosion resistance of the surface-modified porous NiTi alloys immersed in physiological saline and electrochemical solution were evaluated.
The results have shown that the oxide film mainly composed of anatase TiO2 and depleted in Ni formed on porous NiTi surface by high temperature oxidation. The content of anatase TiO2 phase increases with the oxidation temperature. However, an over high temperature (e.g., >500 oC) tends to induce cracking of the surface film caused by internal thermal stress and thus deteriorate the interface strength between the oxide film and NiTi substrate. The results of corrosion resistance tests indicate that the uniformity and integrity of the protective oxide film play a key in improving corrosion resistance of porous NiTi alloy.
After a chemical oxidation in H2O2+HCl solution, the oxide film composed of the amorphous oxide and depleted in Ni formed on porous NiTi surface. The defect-free oxide film can significantly enhance corrosion resistance of the substrate and reduce Ni ion release, thus would greatly improve biocompatibility of porous NiTi alloys. The preliminary study of oxidation kinetics has shown that the mass variation of porous NiTi substrate, determined by the HCl concentration and oxidation time, depends on the balance of the kinetics between the oxidation and dissolution reactions during the chemical oxidation process.
It has been shown that the amorphous titanium oxide formed through chemical oxidation followed by high temperature oxidation. At a relatively low temperature of 400oC, the amorphous titanium oxide changed into crystalline anatase TiO2. Although the follow-up high temperature treatment had an adverse influence on interface strength between the oxide film and NiTi substrate, the anatase TiO2 phase provides the possibility for the deposition of HA.
引文
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[31]胡涛,储成林,孙卫斌等.镍钛合金的高级氧化法表面改性及其血液相容性研究[J].稀有金属材料及工程,2007, 36(6): 1074-1077
[32]耿芳,石萍,Cheng F . T. NiTi形状记忆合金表面TiO2薄膜的制备及其血液相容性[J].中国有色金属学报, 2004, 6(47): 250 - 258
[33] Cheng F. T., Shi P., Man H. C. Anatase coating on NiTi via a low-temperature sol-gel route for improving corrosion resistance [J]. Scripta Materialia, 2004, 51:1041-1045
[34] Villermaux F., Tabrizian M., Yahia L. H., et al. Excimer laser treatment of NiTi shape memory alloy biomaterials [J]. Applied Surface Science, 1997, 109:62-66
[35]李波,李小侠,王天民. NiTi合金基TiN薄膜的血液相容性和耐腐蚀性研究[J].稀有金属材料与工程, 2007, 5(36):121-127.
[36] Wong M. H., Cheng F. T., Man H. C. Characteristics apatite-forming ability and corrosion resistance of NiTi surface modified by AC anodization[J]. Applied Surface Science, 2007, 253:7524-7527
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[39] Jiang H. C., Rong L. J. Effect of hydroxyapatite coating on nickel release of the porous NiTi shape memory alloy fabricated by SHS method[J]. Surface and Coatings Technology, 2006, 201:1017-1021
[40] Kokubo T., Miyaji F., Kim H. M. Spontaneous formation of bonelike apatite layer on chemically treated titanium metals[J]. American Ceramic Society, 1996, 79:1127-1129.
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[2] Banks R. Shape Memory Effects in Alloys [M]. New York: Plenum Press, 1975
[3]华英杰. NiTi生物医学材料表面改性电子结构研究[D].大连:大连理工大学,2003
[4] Yahia L. H., Lombardi S., Hagemeister N., et al. Improvement of cyto-compatibility and biomechanical compatibility of NiTi shape memory alloys[J]. Applied Biomechanics, 1995, (10):19-24
[5] Assad M., Yahia L. H., Lemieux N., et al. Comparative in vitro biocompatibility of nickel-titanium, pure nickel, pure titanium, and stainless steel: Genotoxicity and atomic absorption evaluation[J]. Bio-Medical Materials and Engineering, 1999, 9:1-12
[6] Gjunter V. E. Superelastic shape memory implants in maxillofacial surgery, traumatology, orthopaedics and neurosurgery[M]. Tomsk University Publishing House, 1995:13
[7] Dambaev G. Z., Gjunter V. E., Radionchenko A. A., et al. Porous permeable superelastic implants in surgery[M]. Tomsk University Publishing House, 1996:25
[8] Austin G. T. The use of ceramics as an implant material in the cavity[J]. J Milit Med Univers, 1981, 46(1):50
[9]王寿文.多孔面金属植入物骨长入生物固定作用,国外医学外科学分册[J]. 1991, 18(3):156-159
[10]杨杰,吴月华.形状记忆合金及其应用[M].合肥:中国科学技术大学出版社,1992
[11]邢树忠,王世栋,宋晓陵等.自蔓延高温合成镍钛形状记忆合金的生物医学基础研究第二部分:组织植入实验[J].上海生物医学工程.1999, 20(4):3-5
[12]邢树忠,唐玲芳.自蔓延高温合成镍钛形状记忆合金的生物医学基础研究第三部分:毒理学实验[J].上海生物医学工程,2000,21(1):3-7
[13]胡飞.元素粉末烧结法制备医用多孔TiNi合金的研究[D].天津:天津大学, 2002
[14] Rhalmi S., Odin M., Assad M., et al. Hard, Soft tissue and in vitro cell response to porous nickel-titanium: a biocompatibility evaluation[J]. Bio-Medical Materials and Engineering, 1999, 9(3):151-162
[15] Yuan B., Zhang X. P., Chung C. Y., et al. A comparative study of the porous TiNi shape memory alloys fabricated by three different process[J]. Metallurgical and MaterialsTransactions A, 2005, 37:755-761
[16]姜淑文,齐民.生物医用多孔金属材料的研究进展[J].材料科学与工程, 2002, 20(4):597-600
[17]姜海昌,戎利建.多孔NiTi形状记忆合金中Ni的释放行为[J].金属学报,2008, 44(2):198-202
[18] Wu S.L., Liu X. M.,Chan Y. L.,et al. Nickel release behavior and surface characteristics of porous NiTi shape memory alloy modi?ed by different chemical processes[J]. Journal of Biomedical Materials Research-Part A, 2008, 89(2): 483-489
[19] Morgan N. B. Medical shape memory applications-the market and its products[J]. Materials Science and Engineering A. 2004, 378: 16-23
[20]李丙运,戎利建,李依依等.生物医用多孔NiTi合金的研究进展[J],材料研究学报,2000, 14(6):561-565
[21] Itin V. I., Gjunter V, E., Khodorenko V. N., et al. Dynamics of porous penetrable titanium nickelide penetration by human tissues and mechanical behavior of titanium nickelide human tissues composites[J]. Pisma V Zhurnal Tekhnicheskoi Fiziki, 1996, 22(37)
[22]杨大智,吴明雄. NiTi形状记忆合金在生物医学领域的应用[M].北京,冶金工业出版社,2003:129
[23]邢树忠,王世栋,杨晓曦等.自蔓延高温合成镍钛形状记忆合金的生物医学基础研究第一部分:多孔体的研制[J].上海生物医学工程,1999, 20(3): 3-5
[24]牛金龙,张镇西,蒋大宗.多孔羟基磷灰石生物陶瓷的合成和特性研究进展[J].生物医学工程学杂志, 2002, 19(2): 302-305
[25] Trigwell S., Hagden R. D., Nelson K. F., et al. Effect of surface treatment on the surface chemistry of NiTi alloy for biomedical application [J]. Surface and Interface analysis, 1998, 26(7): 483- 489
[26] Lide D. R., Weast R. C., Selby S. M. Handbook of Chemistry and Physics[M]. Boca Raton: CRC Press Inc, 1982.36
[27] Gu Y. W., Tay B. Y., Lim C. S., et al. Biomimetic deposition of apatite coating on surface-modified NiTi alloy[J]. Biomaterials, 2005, 26(24): 6916-6924
[28] Gu Y. W., Tay B .Y., Lim C. S., et al. Characterization of bioactive surface oxidation on NiTi alloy[J]. Applied Surface Science, 2005, 252(5): 2038-2049
[29]杨贤金,何菲,朱胜利等.化学修饰对NiTi形状记忆金氧化膜的影响[J] .功能材料, 2002, 33(2): 169-171
[30] Trepanier C., Tabrizian M., Yahia L. H., et al. Effect of modification of oxide layer on NiTi stent corrosion resistance [J]. Journal of Biomedical Materials Research, 1998, 43: 432- 440
[31]胡涛,储成林,孙卫斌等.镍钛合金的高级氧化法表面改性及其血液相容性研究[J].稀有金属材料及工程,2007, 36(6): 1074-1077
[32]耿芳,石萍,Cheng F . T. NiTi形状记忆合金表面TiO2薄膜的制备及其血液相容性[J].中国有色金属学报, 2004, 6(47): 250 - 258
[33] Cheng F. T., Shi P., Man H. C. Anatase coating on NiTi via a low-temperature sol-gel route for improving corrosion resistance [J]. Scripta Materialia, 2004, 51:1041-1045
[34] Villermaux F., Tabrizian M., Yahia L. H., et al. Excimer laser treatment of NiTi shape memory alloy biomaterials [J]. Applied Surface Science, 1997, 109:62-66
[35]李波,李小侠,王天民. NiTi合金基TiN薄膜的血液相容性和耐腐蚀性研究[J].稀有金属材料与工程, 2007, 5(36):121-127.
[36] Wong M. H., Cheng F. T., Man H. C. Characteristics apatite-forming ability and corrosion resistance of NiTi surface modified by AC anodization[J]. Applied Surface Science, 2007, 253:7524-7527
[37]隋解和,吴冶,王志学等.不同等离子源形成的DLC涂层对Ni2Ti合金腐蚀行为的影响[J ].功能材料, 2006, 9(15):66-72
[38] Wu S. L., Liu X. M., Chan Y. L., et al. Nickel release behavior, cytocompatibility, and superelasticity of oxidized porous single-phase NiTi[J]. Jouranal of Biomedical Material Research A , 2007,1:948-955
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