【作者】 冯兴国；

【导师】 马欣新；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2013， 博士

【摘要】 为了提高Ti6Al4V合金的耐磨性能，本文采用多靶磁控溅射与等离子体基注氮方法在Ti6Al4V合金表面分别制备了四元TaNbTiW合金薄膜，（TaNbTiW）N氮化物薄膜，五元ZrTaNbTiW合金薄膜和（ZrTaNbTiW）N氮化物薄膜。采用X射线荧光光谱（XRF）、X射线光电子能谱（XPS）、X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）等分析手段对薄膜的化学成分，元素价态、相组成和微观结构进行了分析，研究了薄膜的摩擦磨损性能并对其机理进行了分析。通过磁控溅射在Ti6Al4V合金上制备了TaNbTiW合金薄膜，并对薄膜的组织结构与性能进行了研究。研究表明，TaNbTiW合金薄膜为简单的体心立方结构且各衍射峰的位置随着Ta、Nb含量的减少及Ti、W含量的增加逐渐向高角度方向移动。TaNbTiW合金薄膜在500，700和900℃退火时具有良好的相稳定性和抗氧化性能，且随着Ti和W含量的增加薄膜的抗氧化性能增强。场发射扫描电子显微镜（FESEM）分析结果显示，TaNbTiW合金薄膜的表面为颗粒状，断面为柱状晶结构。在Ti6Al4V合金基体上沉积的TaNbTiW合金薄膜的最大硬度为5.2GPa，较基体硬度提高了13%左右。摩擦系数较基体有所上升，但比磨损率较基体下降了17%。采用磁控溅射和等离子体基注氮方法制备了（TaNbTiW）N氮化物薄膜。XPS结果表明，TaNbTiW合金薄膜注氮后形成了Ta-N、Nb-N、Ti-NO、Ta-O化学键和Ta⁰⁺、W⁰⁺价态。XRD结果表明，（TaNbTiW）N薄膜由体心立方和面心立方固溶体组成。TaNbTiW合金薄膜注氮后，其硬度和弹性模量都有显著提高且随着注氮时间的增加而增大，Ta_25.4Nb_13.4Ti_20.9W_40.3注氮3h试样具有最大的硬度和弹性模量，其值分别达到9.0和154.1GPa。注氮之后摩擦系数较合金薄膜有显著降低，耐磨性能较合金薄膜和基体Ti6Al4V都有明显提高，注氮1h薄膜具有最小的比磨损率，较四元合金薄膜降低了200%，较基体Ti6Al4V下降了223%。氮化物薄膜的磨损机理主要是磨粒磨损，同时也存在粘着磨损。采用多靶磁控溅射制备了五元ZrTaNbTiW合金薄膜。XRD分析结构表明，ZrTaNbTiW合金薄膜为简单的体心立方或非晶相。当薄膜中Zr含量超过35at%时，出现非晶相。该薄膜在500、700和900℃退火无相转变发生，具有良好的相稳定性，且随着Ti和W含量的增加，薄膜的抗氧化性能提高。FESEM分析结果表明，ZrTaNbTiW合金薄膜的表面形貌为颗粒状，断面形貌为柱状晶。随着Zr含量的增多，表面颗粒逐渐变小，断面柱状晶结构逐渐变致密。ZrTaNbTiW合金薄膜的最大硬度为6.7GPa。ZrTaNbTiW合金薄膜的摩擦系数为0.35左右，较基体Ti6Al4V合金高，但比磨损率显著低于基体Ti6Al4V，最大下降了2倍多，其磨损机制主要为磨粒磨损和粘着磨损，同时伴有轻微的氧化磨损。采用多靶磁控溅射和等离子体基注氮方法制备了（ZrTaNbTiW）N氮化物薄膜。XPS分析结果表明，薄膜中存在Ta-N、Nb-N、Ti-N、Zr-N、Zr-O化学键和Nb⁰⁺、W⁰⁺价态。XRD结果显示，五元合金薄膜ZrTaNbTiW注氮之后相结构为体心立方和面心立方组成的固溶体。（ZrTaNbTiW）N薄膜的断面为宽度约为30nm的柱状晶。注氮后，薄膜的硬度和弹性模量都有显著提高，最大硬度和弹性模量分别达到13.5和178.9GPa，耐磨性能较其合金薄膜ZrTaNbTiW和基体Ti6Al4V都有较大的提高，比磨损率分别下降了3.6倍和5倍。通过对TaNbTiW合金薄膜分别注N，加入Zr元素，加Zr元素后注N分析发现，TaNbTiW合金薄膜注氮后，薄膜中形成了面心立方结构的氮化物，晶体结构由原来的体心立方转变为体心立方和面心立方的混合固溶体。Zr元素加入TaNbTiW合金薄膜后，薄膜的晶格畸变增大，当Zr、Ta、Nb、Ti和W各元素含量属于高熵薄膜范畴时，薄膜具有较高的混合熵，晶格畸变和高的混合熵导致薄膜中形成非晶相。在TaNbTiW薄膜中加入Zr元素后注N，薄膜中不但形成了面心立方的氮化物而且显著增大了薄膜的混合熵，薄膜的晶体结构为面心立方和体心立方固溶体。TaNbTiW薄膜具有较高的硬度和耐磨性能，且随着Zr元素的加入，N离子的注入，Zr元素加入之后注N，薄膜的硬度和耐磨性能呈现依次增大趋势。更多还原

【Abstract】 In order to improve the wear resistance of Ti6Al4V alloy, multi-target magnetronsputtering and nitrogen plasma based ion implantation are used to preparedquaternary TaNbTiW alloy films,（TaNbTiW）N nitride films, quinary ZrTaNbTiWalloy films and （ZrTaNbTiW）N nitride films. The chemical composition, chemicalbonds, constituent phase, microstructure are investigated using X-ray fluorescencespectroscopy （XRF）, X-ray photoelectron spectroscopy （XPS）, XRD, SEM andTEM techniques. Wear properties and its mechanism of the films are analyzed.Quaternary TaNbTiW alloy films are deposited on Ti6Al4V alloy by magnetronsputtering. Structure and performance of the films are investigated. XRD shows thatthe films have body-centered cubic （BCC） structure, and the diffraction peaks areshift to higher angle with the decreasing of Ta, Nb content and increasing of Ti, Wcontent. The films that annealed at500,700,900℃have good phase stability andoxidation resistance, and the oxidation resistance is enhanced with the increasing ofTi, W content. The field emission scanning electron microscope （FESEM）observation shows that the top surface of the films is granular-like structure, and thecross-section is columnar structure. The maximum hardness of the film deposited onTi6Al4V is5.2GPa; it is increased about13%compared to Ti6Al4V substrate. Thefriction coefficient of the films is higher than Ti6Al4V alloy, but the wear rate isdecreased17%.（TaNbTiW）N films are prepared by combining of magnetron sputtering depositionand nitrogen plasma based ion implantation （N-PBII）. XPS investigations indicatesthat the nitride films are like composed of Ta-N, Nb-N, TiNxOy, TaOx, Ta and W.XRD shows that the nitride films are composed of BCC and FCC solid solutionstructures. The hardness and modulus of the nitride films are increased withincreasing implantation time and the hardness and modulus of alloy filmTa_25.4Nb_13.4Ti_20.9W_40.3implanted3h reaches maximum values of9.0and154.1GPaafter nitrogen implantation. The friction coefficient and the wear rate of（TaNbTiW）N films are significantly decreased compared to TaNbTiW alloy filmsand substrate Ti6Al4V. The1h nitrogen implantation film has minimal wear rate. Ascompared to alloy film and substrate, it is decreased200%and223%, respectively.The wear mechanism of the nitride film is abrasive wear, accompanied by adhesivewear.Quinary ZrTaNbTiW alloy films are prepared by multi-targets magnetronsputtering. XRD shows that the alloy films ZrTaNbTiW are simple BCC structure or amorphous. When the atomic percent of Zr exceeded35%, the films are exhibitedamorphous phase. The films that annealed at500,700,900℃have good phasestability and oxidation resistance, and the oxidation resistance is enhanced with theincreasing of Ti, W content. FESEM analysis results show that the top surface of thefilms is granular-like structure, and the cross-section is columnar structure. Thesurface particles gradually become small and columnar crystal gradually becomesdense with the increasing of Zr content. The maximum hardness of the filmdeposited on Ti6Al4V alloy is6.7GPa. The friction coefficient of the films is about0.35, higher than Ti6Al4V alloy. But the wear rate is significantly lower thanTi6Al4V alloy; it is decreased more than2times. The wear mechanism is mainlyabrasive wear and adhesive wear, accompanied by oxidative wear.Multi-element （ZrTaNbTiW）N films are prepared by multi-target magnetronsputtering deposition and nitrogen plasma based ion implantation （PBII）. It is seenthat a mixture of ZrN, TaN, TiN, Nb-N, ZrO₂, Ta, Nb and W is formed. Afternitrogen implantation, the alloy films （ZrTaNbTiW）N are composed of BCC andFCC solid solution and the width of columnar grain is about5nm. The hardness andmodulus of the films are improved significantly after nitrogen ion implantation andreach maximum values of13.5and178.9GPa, respectively. The （ZrTaNbTiW）Nfilms have better wear resistance than its ZrTaNbTiW alloy films and Ti6Al4Vsubstrate, the wear rate is decreased3.6times and5times, respectively.Through studying on the nitrogen implantation in TaNbTiW films, Zr additionin TaNbTiW films, and Zr addition then nitrogen in TaNbTiW films, respectively. Itis found that FCC nitrides are formed in the TaNbTiW films after nitrogenimplantation. The structure of the films is changed to FCC and BCC solid solution.After Zr addition in TaNbTiW films, the lattice distortion is increased. When thecontent of the each element Zr, Ta, Nb, Ti and W are in the range of the high entropyfilms, the films have high mixing entropy. So the lattice distortion and high mixingentropy lead to the formation of amorphous phase. When the TaNbTiW films addedZr then nitrogen implanted, not only BCC nitrides formation but also significantlyincreases the mixing entropy of the films. The structure of the films is BCC andFCC solid solution. The TaNbTiW films have high hardness and wear resistance,and with the Zr addition, nitrogen implantation, Zr addition then nitrogenimplantation, the hardness and wear resistance presents successively increasingtrend.更多还原