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Titanium nitride (TiN) films were fabricated on AISI52100 bearing steel surface employing a hybrid plasma immersion ion implantation and deposition (PIIID) technique. The chemical composition, morphology and microstructure of TiN films were characterized by atomic force microscope (AFM), energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The residual stress of TiN films under different deposition parameter conditions were measured by means of glazing incidence angle X-ray diffraction (GIXRD) method. The influence of film thickness and X-ray glazing incidence angle on residual stress were investigated. AFM observation reveals that the TiN films have extremely smooth surface, high uniformity and efficiency of space filling over large areas. XRD analysis results indicate that TiN phase exists in the surface modified layer and exhibits a preferred orientation with the (2 0 0) plane. The GIXRD data shows that the residual stress in as-deposited TiN films is compressive stress, and the residual stress value decreases with the film thickness and increases with the glazing incidence angle. The compressive stress reduces from 2.164 GPa to 1.163 GPa, which corresponds to the film thickness from 1.5 μm to 4.5 μm, respectively. Reasonably selecting PIIID process parameters for TiN films fabrication, the residual stress in the film can be controlled effectively.

TiN/ZrO2 multilayers with different modulation periods were synthesized on GCr15 bearing steel using plasma immersion ion implantation and deposition (PIIID). The total thickness of the TiN/ZrO2 multilayers was approximately 2 μm and the modulation period was varied from 8 to 400 nm. The as-deposited films were characterized by scanning electron microscopy (SEM), micro-hardness, friction, scratch and corrosion tests. The SEM result indicates that the structure of the TiN/ZrO2 multilayers has a good periodicity. Micro-hardness testing results show that the hardness enhancement effect takes place at the specific period of 15 nm, 100 nm and 200 nm. In addition, the friction coefficient declined from 0.8 to 0.1–0.3 and the cut-through number was increased greatly. The critical load in the scratch test exceeds 100 N, which shows a high adhesion strength. Moreover, the corrosion resistance of the TiN/ZrO2 multilayers was improved significantly at the modulation period of 100 nm and 200 nm.

The effect of plasma immersion ion implantation and deposition (PIII&D) titanium carbide (TiC) film on the rolling contact fatigue (RCF) life of coated on AISI52100 bearing steel surface is studied experimentally. Testing include plan-view optical microscopy (OM), X-ray diffraction (XRD), friction and wear behaviors, rolling contact fatigue life and nano-indentation measurements. XRD patterns show that titanium carbide phase is formed in the film, and the microhardness of treated samples is higher than that of substrate. Rolling contact fatigue failure tracks were observed using conventional light microscope. Surface wear and adhesive delamination existed. Results indicate that the maximum RCF life of the treated sample prolong by 6.5 times at a Hertzian stress level of 5.1 GPa and 90% confidence level, respectively. Comparison with the substrate, the maximum microhardness of treated specimen is increased by 28.4%. The friction coefficient decreased from 0.95 to 0.15 under identical wear conditions. This remarkable fatigue performance appears to be due to a combination of improved microstructure, adhesion, hardness and surface topography. Therefore, the PIII&D is regarded as one of the promising technologies for improving the RCF life of bearing.

As a crystallization process, the field-aided lateral crystallization (FALC) technique has some outstanding advantages, such as high crystallization rate and low temperature. In this study, the electrical field was directly applied between source and drain areas of H shape patterns using the Mo–W interconnecting layer. The effects of the current density and electrical field strength on the crystallization behavior were investigated. Results show that the crystallization behaviors at different bias areas are different. The difference is attributed to the coexisting effects of electromigration and potential gradient. In addition, the dependence of the degree of crystallization on the current density was studied by Raman spectra and the microstructure crystallized by FALC was observed by a scanning electron microscope.

TiN films were synthesized on GCr15-bearing steel by plasma immersion ion implantation and deposition (PIIID). During the experiments, the bias voltage was varied from −10 to −30 kV, and the ratio of implantation to deposition was adjusted from 1:10, 1:20, 1:30 to 1:40 by changing the pulse durations of the bias voltage and the vacuum arc discharge. Adhesion strength tests were carried out by scratch test. The results reveal that the adhesion strength between the film and the substrate is influenced by the bias voltage and the ratio of implantation to deposition significantly. In addition, the pretreatment of substrates and the interface layer have some impacts on the final adhesion strength.

Titanium carbide films have been synthesized by plasma immersion ion implantation and deposition (PIIID) on 9Cr18 bearing steel. During the experiments, acetylene (C2H2) and titanium plasmas were generated simultaneously. Acetylene plasma was produced by a radio-frequency plasma source, and titanium plasma was generated by cathodic arc plasma source. Influences of gas pressure and pulse width of the bias voltage on properties of the thin film were investigated. The as-deposited films were characterized by X-ray diffraction (XRD), micro-hardness tester, pin-on-disc tribological facility and electrochemistry corrosion equipment. XRD pattern proves that TiC phase is formed in the film. Compared with uncoated substrates, micro-hardness results reveal that the maximum micro-hardness is increased by 70.8%. In addition, the friction coefficient decreases to about 0.1, and the corrosion resistance of coated substrate surfaces is improved significantly.

The effects of the substrate temperature and ion impact energy on the surface roughness and morphology of insulating cerium oxide films fabricated by dual plasma deposition were investigated. Cerium oxide films were synthesized on Si(1 0 0) substrates, and the influence of the substrate temperature and applied voltage on the surface roughness was systematically studied. Our results indicate that the roughness of the deposited films decreased when the substrate temperature was increased, probably because of enhanced surface diffusion of the adatoms. The ion kinetic energy had a similar effect as the substrate temperature, and it is believed that a higher ion kinetic energy also improves the surface diffusion of adatoms. It is found that a direct-current voltage applied to the substrate could lead to a rougher surface, whereas an appropriate alternating-current voltage gave rise to a smoother topography.

In the aerospace industry, 9Cr18 martensitic stainless steel AISI 440 is commonly used as a bearing material. Because of its . ability to rapidly treat irregular industrial components, plasma immersion ion implantation PIII is an effective method to improve the wear resistance of 9Cr18 precision bearings and prolong their working lifetime. Vacuum arc plasma sources provide a good means of introducing metal ions into the bearing steel to create a special surface to enhance its surface properties. In this work, tungsten and titanium PIII was performed on 9Cr18 bearing steel using a vacuum arc plasma source, followed by carbon . PIII using acetylene C H plasma, without breaking the vacuum. The surface properties were evaluated by measuring the 22 microhardness, wear properties and friction coefficient, as well as the elemental depth profiles and chemical composition of the modified layer. It was found that the microhardness of the treated samples was much higher. The tribological characteristics were also significantly improved, as demonstrated by the reduced friction coefficient and wear track width. This improvement can be . attributed to the diamond-like-carbon DLC surface layer, as well as favorable ion mixing caused by the implanted metal ions. Q 2000 Elsevier Science S.A. All rights reserved.

Plasma-based ion implantation (PBII) is a burgeoning surface treatment technique as it offers the possibility of treating complex-shaped and large samples without target manipulation. However, the technique has not been widely adopted in the metallurgical industry due to the difficulty to achieve a thick modified layer at low temperature. In this paper, we describe a method combining PBII and ion mixing to synthesize titanium nitride (TiN) on 304 stainless steel. Titanium and nitrogen ions are generated by a metal arc plasma source and hot filament glow discharge, respectively. By using three different sets of experimental conditions, we investigate the effects of different implantation and deposition parameters on the surface properties of TiN. Results from Auger electron spectroscopy, glancing X-ray diffraction, pin-on-disk test, and microhardness determination reveal significantly improved tribological properties. The enhancement is a consequence of the synergistic effects of the coexistence of titanium, oxygen, and nitrogen, as well as the ion mixed interface.

A surface layer consisting of titanium, nitrogen, and oxygen is implanted/deposited onto SS304 stainless steel using dynamic mixing and plasma immersion ion implantation. Titanium is introduced into a nitrogen glow discharge plasma from a metal arc plasma source. Dynamic mixing is achieved via the co-implantation of Ti ions with high charge states as well as nitrogen and oxygen ions in the plasma. The resulting surface layer possesses superior tribological properties and corrosion resistance. The observed improvement in the wear resistance is more than a factor of 10. The enhancement in the surface properties is believed to be due to the synergistic effects of the coexistence and dynamic mixing of titanium, nitrogen, and oxygen at the interface.

Employing an improved vacuum arc plasma source, metal plasma immersion ion implantation (PIII) is performed on 9Cr18 bearing steel. Titanium, tantalum, molybdenum and tungsten ions are implanted followed by nitrogen PIII to result in a modified surface layer with superior wear resistance. The surface properties of the 9Cr18 bearing steel samples are evaluated by measuring the microhardness, wear property, coefficient of friction, as well as elemental depth profiles and chemical composition of the modified layer. The results show that the wear resistance of the samples treated by metal plus nitrogen PIII is enhanced to a larger degree than that of the samples undergoing nitrogen PIII alone. The XPS results indicate that some nitride phases have been formed in the implanted layer. In this paper, we will also discuss the improvement on the metal vacuum arc plasma source and experimental protocols. Using metal and gas PIII, the surface properties of 9Cr18 bearing steel are enhanced significantly.

This article reports on the measurement of the ion current in plasma immersion ion implantation. Our simulation results indicate that the total current peaks at the end of rise time of the applied voltage. However, our experimental data acquired using a Rogowski coil and digital oscillator show the highest current at the beginning of the voltage pulse. The discrepancy can be explained by a displacement current attributable to the changing voltage, sheath capacitance, circuit loading effects, as well as secondary electron emission.

Titanium is a promising material for medical implants, replacing bones and teeth. However, at pH values below 2, which occur in the dental environment, the corrosion resistance is compromised. The deposition of niobium layers onto titanium is a possibility to increase the corrosion resistance, as measured in 5 N HCl solution.

Metal plasma-immersion ion implantation (PIII) employing an improved vacuum-arc plasma source is performed on 9Cr18 bearing steels. Titanium and tantalum ions are implanted followed by nitrogen plasma-immersion ion implantation to yield a modified surface layer with superior wear resistance. The surface properties of the 9Cr18 bearing steel samples are evaluated by measuring the microhardness, wear properties and coefficient of friction. Elemental depth profiles and the chemical composition of the modified layer are acquired by Auger electron spectroscopy and X-ray photoelectron spectroscopy. The results show that the wear resistance of the samples implanted with (Ti+N) and (Ta+N) is better than that of the samples undergoing nitrogen PIII alone. The XPS results indicate the presence of nitride phases in the implanted layer. In this paper, the new improvements made on the metal-arc source are described. Using the new procedures incorporating both metal-ion and gas PIII, the surface properties of 9Cr18 bearing steel are significantly improved.

Plasma immersion ion implantation (PIII) is an effective technique to enhance the surface properties of industrial components possessing an irregular shape. However, it is difficult to achieve uniform implantation along the groove surface of a ball bearing. In this work, we focus on the PIII treatment of the arc surface of an industrial ball bearing. Three practical sample placement configurations are investigated: I) direct placement on the sample stage platen, II) placement on a copper extension with the same diameter as the bearing race, III) placement on a copper plate erected on the sample stage by means of a small metal rod. Using theoretical simulation, the implant dose uniformity along the groove surface is determined for the three orientations. Our results reveal that configuration III) yields the largest implant dose along the groove surface and the dose uniformity is worse in configuration I). Hence, in order to improve the lateral dose uniformity along the race surface, the bearing should be elevated from the sample.

Plasma immersion ion implantation (PIII) is employed to enhance the tribological properties of titanium. The effectiveness of methane PIII and glow discharge nitrogen PIII, as well as radio-frequency (RF) nitrogen PIII, is compared by measuring the microhardness, mass loss due to wear and the coefficient of friction of samples treated by the three methods. Nitrogen PIII is a hybrid surface treatment technique combining nitrogen-ion implantation, which occurs during the high-voltage pulses, and plasma nitriding, which takes place in between pulses. Our experimental data show that the surface properties of titanium are enhanced by all three treatment processes, but nitrogen PIII yields better results than methane PIII, and RF nitrogen PIII is the best treatment process of the three. On the basis of our Auger depth profiling results, the discrepancy appears to be related to the larger penetration depth (implantation plus radiation-enhanced diffusion) of nitrogen by the RF PIII process. The slight difference between methane PIII and glow discharge nitrogen PIII samples appears to arise from the absolute implanted dose.

A model utilizing cold, unmagnetized, and collisionless fluid ions as well as Boltzmann electrons is used to comprehensively investigate the sheath expansion into a translationally invariant large bore in the presence of an auxiliary electrode during plasma immersion ion implantation (PIII) of a cylindrical bore sample. The governing equation of ion continuity, ion motion, and Poisson’s equation are solved by using a numerical finite difference method for different cylindrical bore radii, auxiliary electrode radii, and voltage rise times. The ion density and ion impact energy at the cylindrical inner surface, as well as the ion energy distribution, maximum ion impact energy, and average ion impact energy for the various cases are obtained. Our results show a dramatic improvement in the impact energy when an auxiliary electrode is used and the recommended normalized auxiliary electrode radius is in the range of 0.1–0.3.

45 # carbon steel is commonly used in the industry but vulnerable to wear and corrosion in the field. Replacing it with stainless or alloy steel increases the cost significantly, and a better alternative is to improve its surface properties and lifetime using plasma immersion ion implantation (PIII). We have evaluated a variety of treatment processes including nitrogen PIII, radio-frequency (RF) plasma nitriding together with nitrogen PIII, Ti (Cr) deposition in conjunction with nitrogen PIII (IBED), as well as nitrogen PIII on samples electroplated with a layer of hard Cr. To assess the efficacy of each process, the microhardness, mass loss due to wear, coefficient of friction, and anode polarization curve were measured on both the untreated and treated 45 # samples. Our experimental results show that the surface properties of 45 # steel are enhanced by all of these methods, but to a different extent. The IBED technique produces the best enhancement data. For instance, the microhardness increases by almost a factor of 2, mass loss due to wear is reduced by 31/2 times, and the coefficient of friction diminishes by 21/2 times. The RF plasma nitriding/nitrogen PIII technique produces less dramatic enhancement results but is more desirable for complex-shaped industrial components. The hard Cr-electroplating/nitrogen PIII technique is excellent but appears to be least desirable because of environmental impact.

Nitrogen ion implantation improves the wear resistance of Ti-6A1-4V alloys by forming a hard TiN superficial passivation layer. However, the thickness of the layer formed by traditional ion implantation is typically 100–200 nm and may not be adequate for many industrial applications. We propose to use radio-frequency (RF) plasma nitriding and nitrogen plasma immersion ion implantation (PIII) to increase the layer thickness. By using a newly designed inductively coupled RF plasma source and applying a series of negative high voltage pulses to the Ti-6A1-4V samples, RF plasma nitriding and nitrogen PIII can be achieved. Our process yields a substantially thicker modified layer exhibiting more superior wear resistance characteristics, as demonstrated by data from micro-hardness testing, pin-on-disc wear testing, scanning electron microscopy (SEM), as well as Auger electron spectroscopy (AES). The performance of our newly developed inductively coupled RF plasma source which is responsible for the success of the experiments is also described.

Titanium Nitride (TiN) films were prepared on AISI52100 bearing steel surface by plasma immersion ion implantation and deposition (PIII&D) technique. The as-deposited films have been characterized using a series of test methods. X-ray diffraction (XRD) proves that the surface layer is mainly composed of TiN phase with fee structure. The depth profiles and chemical bonds were analyzed with X-ray photoclectron spectroscopy (XPS) combined with Ar ion etching. Atomic force microscope (AFM) reveals that the TiNFilm has extremely smooth surface, very high uniformity and efficiency of space filling over large areas. The maximum nanohardness (H) and elastic modulus (E) of treated samples is 25GPa and 350GPa, increases by 127.3% and 59.1%. The friction and wear behaviors, rolling contact fatigue (RCF) life of all these samples were also investigated by ball-on-disc and three-ball -rod testers. Results show that the friction coefficient decreases from 0.92 to 0.2. Compared with the untreated substrate, the L 10, L 50, L a and mean life L of treated samples increases by 5.5, 2.8, 2.3 and 2.2 times, respectively. It indicates that PIII&D has been successful in depositing high-quality TiN films on bearing steel components, and beneficial in improving the mechanical properties and RCF life.

High energy implantation of metal ions can be carried out using conventional ion implantation with a mass-selected ion beam in scanned-spot mode by employing a broad-beam approach such as with a vacuum arc ion source, or by utilizing plasma immersion ion implantation with a metal plasma. For many high dose applications, the use of plasma immersion techniques offers a high-rate process, but the formation of a surface film along with the subsurface implanted layer is sometimes a severe or even fatal detriment. We describe here an operating mode of the metal plasma immersion approach by which pure implantation can be obtained. We have demonstrated the technique by carrying out Ti and Ta implantations at energies of about 80 and 120 keV for Ti and Ta, respectively, and doses on the order of 1×1017 ions/cm2. Our experiments show that virtually pure implantation without simultaneous surface deposition can be accomplished. Using proper synchronization of the metal arc and sample voltage pulse, the applied dose t...

As a crystallization process, the field-aided lateral crystallization (FALC) technique has some outstanding advantages, such as high crystallization rate and low temperature. In this study, an electric field was directly applied between source and drain areas of H shape patterns using the Mo-W interconnecting layer. The effects of the current density and the electrical field strength on the crystallization behavior were investigated. Such crystallization behaviors are attributed to the coexisting effects of electromigration and potential gradient. In addition, the dependence of the degree of crystallization on the current density was studied and the microstructure crystallized by FALC was compared with the microstructure crystallized by metal induced lateral crystallization (MILC) process.

Summary form only given. We have devised a variety of treatment processes using PIII, including radio-frequency (RF) plasma nitriding, RF plasma nitriding and nitrogen PIII, Ti deposition in conjunction with nitrogen PIII (IBED), as well as Cr deposition followed by nitrogen PIII (IBED). To assess the efficacy of the processes, the microhardness and mass loss due to wear were measured for both the untreated and treated 45 samples. A salt fog test was also conducted to evaluate the resistance against rusting. Our experimental results show that the microhardness and resistance against rusting of the treated 45 steel samples are much improved, and the mass loss due to wear is reduced substantially. In this paper, we compare the effectiveness of each treatment technique in addition to showing supporting data.

Plasma immersion ion implantation is a nonline-of-sight method for fabricating amorphous carbon or diamond-like-carbon coatings on steels to improve the surface properties. In this work, carbon thin films are synthesized on 9Crl8 (AISI440) stainless bearing steel by acetylene (C2H2) plasma immersion ion implantation (PIII). The effects of the processing parameters, including rf power, sample voltage pulse duty cycle, and target bias, on the structure and surface properties of the carbon thin films is systematically investigated employing Raman spectroscopy, Auger electron spectroscopy, friction coefficient measurement, and wear test. The results reveal that carbon films several hundred nanometers thick with a well-mixed interface are formed on the 9Crl8 steel after C2H2 PIII, but the structure and properties of the carbon films vary greatly under different PIII conditions. There is an optimal process window within which the synthesized films have superior properties, and current densities that are too hig...