金属等离子体浸没离子注入改善9Cr18轴承钢表面耐磨性的研究

采用新改进的阴极弧金属等离子体源,对９Ｃｒ１８轴承钢进行了金属等离子体浸没离子注入（ＰⅢ）处理,首先将Ｔｉ、Ｍｏ和Ｗ离子分别注入到９Ｃｒ１８钢的表面,然后再对其进行Ｎ等离子体浸没离子注入,从而在９Ｃｒ１８钢表面形成了一层超硬耐磨的改性层。     

空间飞轮轴承等离子体浸没离子注入氮层性能研究

研究了氮等离子体浸没离子注入(PIII)技术处理后空间飞轮轴承内圈的摩擦学性能。通过原子力显微镜分析改性前后试样表面形貌,利用X射线电子能谱分析试样表面成分及结构,通过显微硬度计测量改性前后及不同注入时间下试样表面硬度,考察改性前后试样摩擦系数变化情况。结果表明,空间飞轮轴承内圈进行表面注氮后,表面形成Cr-N化合物,形成第二相及固溶强化使得试样表面硬度显著增加,摩擦系数明显减小,耐磨性增加,轴承组件工作电流明显减小。     

9Cr18轴承钢表面不同等离子体浸没离子注入强化处理技术研究

采用不同的等离子体浸没离子注入(PⅢ)工艺在9Cr18轴承钢表面进行了气体、金属、金属加气体的离子注入和碳化钛(TiC)、类金刚石(DLC)薄膜的等离子体浸没离子注入与沉积(PⅢD).对处理后的试样进行了X射线光电子能谱(XPS)、X射线衍射(XRD)、俄歇电子能谱(AES)和拉曼光谱(Raman)分析;测试了处理前后试样的显微硬度、磨痕宽度和摩擦系数.结果表明:处理后试样表面均形成了不同的改性层,且改性层中化学组成和各元素的浓度-深度分布随处理工艺的不同而变化;处理后试样的显微硬度都有较大提高,最大增幅达77.7%;表面摩擦系数由0.8下降到0.16;磨痕宽度减少了23倍;与PⅢ工艺相比,相同参数下,PⅢD处理后的试样表面综合性能更加优异.     

PIII技术制备c-BN硬化层

采用一种新型的等离子体浸没式离子注入技术(PIII)在渗硼后的50Mn钢试样上制备出了厚度为0.15~0.2mm的立方氮化硼(c-BN)表面硬化层。经X光电子能谱(XPS)和X光衍射分析(XRD),发现硬化层中的组织有立方氮化硼(c-BN)、六方氮化硼(h-BN)、B2O3、FeB和Fe2B。在表层60nm的深度范围内,c-BN的含量较高。采用球盘式无润滑滑动摩擦试验和维氏显微硬度试验分别对渗硼+PIII复合处理以及单独渗硼的50Mn钢试样的性能进行了对比试验。结果表明,与单独渗硼的试样相比,渗硼+PIII复合处理的试样具有高得多的硬度(高达Hv0.1N44GPa)和耐磨性。该项技术在电缆压模上进行了应用试验,获得了较好的应用效果。     

金属等离子体浸没离子注入与沉积技术合成类金刚石薄膜研究

采用金属等离子体浸没离子注入与沉积技术在9Cr18轴承钢基体表面合成了类金刚石薄膜.研究了注入脉宽和工作气压对合成薄膜性能及化学组成的影响;通过激光Raman光谱、维氏硬度、针盘试验和电化学腐蚀等测试手段分别表征了合成薄膜后试样表面的化学组成和微观结构、显微硬度、摩擦磨损性能和抗腐蚀性能.结果表明:合成薄膜后,试样的显微硬度增大了88.7%,摩擦磨损和抗腐蚀性能也明显改善.     

等离子体浸没离子注入及表面强化工艺的进展

等离子体浸没离子注入 (PIII)消除了传统束线离子注入 (IBII)固有的视线限制 ,是一种更适合于处理复杂形状工件的手段 .近十年来 ,PIII及其工业应用在国内外得到了迅速发展 .然而 ,随着PIII的研究与开发的深入 ,发现仍有若干重要的物理与技术问题 ,诸如浅的注入层、离子注入不均匀性、气体 (氮 )等离子体的有限应用范围等等 ,阻碍了PIII工业应用的发展 .目前 ,这些问题已成为国内外学者关注的焦点 .我实验室近年来在注入过程鞘层动力学的计算机理论模拟、离子注入剂量不均匀性改善、圆筒内表面注入研究、新型长射程阴极弧金属等离子体源研制、气体及金属等离子体的综合性表面改性工艺研究、以及低能高温PIII新工艺研究等方面进行了研究工作 .     

工业纯铁等离子体注入与氮化工艺及其性能研究

采用低电压高频率脉冲等离子体浸没离子注入与氮化技术在工业纯铁上进行氮离子注入及氮化强化处理,研究了不同脉冲宽度下,工业纯铁等离子体浸没离子注入与氮化处理的结构及性能.通过X射线衍射谱(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、显微硬度、销-盘磨损实验,研究了工业纯铁氮离子注入及氮化后的结构、断面组织、表面元素含量、显微硬度、摩擦磨损性能;通过电化学极化方法在0.9%NaCl溶液研究了改性层的耐腐蚀性.研究结果表明:氮等离子注入及氮化后能显著提高纯铁表面的显微硬度、耐磨性和耐腐蚀性能,且表面形成结构为Fe3N和Fe4N的针状组织,针状组织是提高纯铁性能的关键因素;高脉冲宽度下进行等离子注入及氮化有利于提高纯铁表面的机械性能和耐腐蚀性能.     

固体润滑轴承用9Cr18不锈钢离子注入与磁控溅射改性真空摩擦学研究

为了提高空间固体润滑滚动轴承耐磨寿命,采用全方位离子注入和磁控溅射技术对空间固体润滑轴承用9Cr18材料进行耐磨减摩表面改性研究。首先对9Cr18不锈钢试样表面注入N+、Ti+、Ti++N+,对离子注入后试样采用磁控溅射技术沉积MoS2-Ti薄膜。通过测试注入前后试样粗糙度及硬度,评价不同注入离子及无离子注入不同基底材料下溅射MoS2-Ti薄膜的附着力、真空摩擦学、薄膜磨损率等性能。结果表明离子注入通过提高9Cr18不锈钢基底硬度,能够提高复合改性后9Cr18不锈钢材料真空摩擦学性能20%。     

9Cr18轴承钢氮等离子体浸没离子注入表面改性工艺及机理的研究

采用不同怕等离子体浸没离子注入工艺对９Ｃｒ１８轴承钢进行了氮离子注入,结果发现,不同条件下的氮离子注入均能显著提高９Ｃｒ１８钢表面的显微硬度和耐磨性,同时耐磨蚀性也明显改善。实验分析结果表明、氮离子注入后试样表面形成了大量的氮化物相,它们在改善材料表面特性中起到了关键的作用。     

45钢等离子体浸没式离子注入层的组织与性能

采用等离子体浸没式离子注入对45钢进行氮离子注入。对注入表层的成分、组织和性能进行了分析。研究结果表明:注入层的剖面氮浓度分布呈高斯分布特征,注入层中有大量氮化物相形成,注入层的显微硬度和摩擦性能有明显改善。     

Effect of surface nanocrystallization on the tribological properties of 1Cr18Ni9Ti stainless steel

Surface nanocrystallization of 1Cr18Ni9Ti austenite stainless steel was conducted by the supersonic fine particles bombarding (SFPB) technique. The friction coefficients and wear losses in air and vacuum were tested to analyse the effect of surface nanocrystallization on the tribological properties of 1Cr18Ni9Ti steel. The results show that the microstructure of the surface layer was refined into nano-grains successfully by SFPB treatment; furthermore, strain-induced martensitic transformation occurred during the treatment. The tribological properties of SFPB treated samples enhanced greatly, The dominant wear mechanism of the original 1Cr18Ni9Ti stainless steel is abrasive wear and adhesive wear, while it transfers to the combined action of fatigue wear, abrasive wear and adhesive wear after surface nanocrystallization by SFPB.     

Surface modification of 2Cr13 oil pump steel by plasma immersion ion implantation–ion beam enhanced deposition (PIII–IBED)

2Cr13 martensite steel is often used as a piston material in oil pumps. In the harsh environment of an oil field, the materials and components undergo extensive and accelerated wear and tear. In this study, we employ Ti and N plasma immersion ion implantation and ion beam enhanced deposition (PIII-IBED) to enhance the surface wear resistance of 2Cr13 steel in an effort to prolong its working lifetime. To assess the technique efficacy and surface properties of the 2Cr13 steel samples treated by PIII-IBED using different voltages, the coefficient of friction, wear tracks, microhardness, anode polarization curves, chemical composition and elemental depth profiles were determined. The experimental data show that the wear resistance of the treated 2Cr13 steel samples is improved significantly by the method, and the nitride phases formed in the modified layer play an important role in the enhancement mechanism.     

New plasma surface-treated memory alloys: Towards a new generation of “smart” orthopaedic materials

This paper describes the corrosion resistance, surface mechanical properties, cyto-compatibility, and in-vivo performance of plasma-treated and untreated NiTi samples. Nickel–titanium discs containing 50.8% Ni were treated by nitrogen and carbon plasma immersion ion implantation (PIII). After nitrogen plasma treatment, a layer of stable titanium nitride is formed on the NiTi surface. Titanium carbide is also found at the surface after carbon plasma implantation. Compared to the untreated samples, the corrosion resistances of the plasma PIII samples are better by a factor of five and the surface hardness and elastic modulus are better by a factor of two. The concentration of Ni leached into the simulated body fluids from the untreated samples is 30 ppm, whereas that from the plasma-treated PIII are undetectable. Although there is no significant difference in the ability of cells to grow on either surface, bone formation is found to be better on the nitrogen and carbon PIII sample surfaces at post-operation 2 weeks. All these improvements can be attributed to the formation of titanium nitride and titanium carbide on the surface.     

Mechanical and ellipsometry measurements of thin TiN layer prepared by PIII

Titanium nitrides have good mechanical, biomedical and optical properties, therefore they are used to harden and protect cutting and sliding surfaces and as a non-toxic exterior for bio-medical applications. Nitrogen plasma immersion implantation (PIII), in which the diffusion of nitrogen from low pressure r.f. plasma is combined with the implantation of nitrogen ions at energies up to 30 kV, is an effective tool for nitriding titanium and titanium alloys. In this work, samples of pure titanium were nitrided by PIII at different negative high voltage pulses. The properties and the characteristics of the processed samples were evaluated using X-ray diffraction (XRD), Auger electron spectroscopy (AES), ball-on-disk type tribometer, surface profilemeter, and ellipsometry measurements. The results show that, the wear resistance of the untreated sample in comparison to the PIII treated samples is extremely poor and the friction coefficient for the PIII treated samples is decreased to the half value in comparison to the untreated titanium, this attributed to the formation of the solid solution titanium α-Ti(N) and the cubic TiN phases. Ellipsometric measurements were carried out on the PIII treated samples at different negative high voltage pulses. A three layers model was used to fit the calculated data to the experimental ellipsometric spectra. The thickness, surface roughness and refractive index increase with increasing the negative high voltage pulses. The refractive index at 550 nm increases from 1.83 to 2.09 as the negative high voltage pulses increases from 10 to 30 kV.     

SURFACE MODIFICATION ISSUES FOR ORTHOPAEDIC IMPLANT BEARING SURFACES

In total joint replacement, generally a polished metal surface articulates against an ultra high molecular weight polyethylene (UHMWPE) counter bearing surface. Metals used include 316L stainless steel, Co-Cr-Mo alloy, and Ti-6AI-4V alloy (particularly with a hardened N⁺ ion implanted surface). Minimizing friction and UHMWPE wear is of prime concern for long-term performance. Additionally, it is desirable to minimize metal ion release which results from constant removal and reformation of passive surface oxides and oxyhydroxides during articulation. Long term effects from the presence of potentially toxic or carcinogenic ions of Cr, Co, Mo, Ni, V, and Al are not well known. Inert ceramic bearing surfaces eliminate this issue and are also resistant to potential three-body wear from bone cement debris or potential stray porous metal coating material. However ceramic (Al₂O₃ and ZrO₂) materials are only available for total hip replacement. For total knee replacement, ft is too difficult and expensive to manufacture a monolithic ceramic knee surface, thus various surface coating methods are being investigated. These methods include plasma sprayed Al₂O₃ and ZrO₂, TiN and amorphous diamond like coatings via PVD/CVD methods, and in-sKu oxidation. In other cases, the existing metal surfaces are simply hardened using methods such as N⁺ ion implantation and oxygen or nitrogen diffusion hardening. This paper reviews the limitations of existing total joint systems and the effectiveness of various surface modification methods of orthopaedic implant bearing surfaces on friction, abrasion, UHMWPE wear, and metal ion release.     

氮离子注入浓度对弹条钢基体Cr/CrSiN复合涂层的摩擦学性能影响研究

在轨道用扣件弹条钢(60Si2Cr)上注入不同浓度的氮离子,用电弧离子镀技术沉积了Cr过渡层,并在其上制备了CrSiN/Cr复合涂层。在UMT-3多功能摩擦磨损机上对复合层进行了法向载荷为20N的摩擦磨损实验,探讨了经不同氮离子注入浓度后Cr/CrSiN复合涂层摩擦磨损行为和损伤机理,研究发现,经氮离子注入后,复合涂层表面硬度明显的增加,随着离子注入浓度的升高涂层的耐磨性逐渐提高,其磨损机制主要为剥落和磨粒磨损。