Surface Engineering Technology Research Articles

Nano Surface Engineering and its Applications

The nano surface engineering technology mainly concludes the nano-materials electric brush plating technology, nano-materials thermal spraying technology and nano-films solid lubrication technology. Through the nano surface engineering, the films or coatings possessing the nano-structure characteristics can be prepared, improving remarkably the wear-resistance, anti-corrosion and fatigue-resistance of the substrate. Although the nano surface engineering enriches the maintenance methods and advances the maintenance effects, it still stands the elementary development period and many fundamental issues deserve to research in depth.

Preparation and Properties of Cathodic Plasma Electrolysis Ni-P Coatings

Cathodic plasma electrolysis (CPE) is an emerging surface engineering technology in the recent years. In present work CPE was successfully used for deposition Ni-P coatings on carbon steel. The deposition experimental results show that CPE possesses high coating deposition rate, faster than 4 μm/min. SEM observations unveil the bonding between Ni-P coating and substrate is metallurgical. XRD diagram analysis indicates that the phases of as-deposited Ni-P coating are Ni and Ni3P, transformed from amorphous to crystallized state. The corrosion resistances of CPE and electroless plating (EP) coating have also been discussed by polarization curves in 3.5% NaCl solution at room temperature. Scratch tester was applied to study film-substrate adhesion of CPE Ni-P coating comparing with EP Ni-P coating.

A Comparative Study: Effects of Two Different Surface Engineering Technologies on Tribological Properties of Pure Titanium

Two different surface engineering technologies, plasma nitriding and titanium nitride (TiN) film deposition by closed-field unbalanced magnetron sputtering (CFUBMS), were used to improve the tribological properties of pure titanium. Surface characteristics were evaluated by microhardness tester, scanning electron microscopy(SEM), X-ray diffraction (XRD) and pin-on-disc tribotester. The influence of the two surface treatments on wear resistance of titanium was investigated. After plasma nitriding or TiN film deposition by CFUBMS, the microhardness of the surface increased approximately 3 to 5 times when compared with that of untreated pure titanium and the wear resistance was improved significantly. The wear resistance of TiN film deposited titanium specimens was higher than that of plasma nitrided ones.

New insights into the mechanism of low-temperature active-screen plasma nitriding of austenitic stainless steel

Low-temperature active-screen plasma nitriding is an effective surface engineering technology to improve the wear and corrosion resistance of austenitic stainless steel through the formation of expanded austenite. The material sputtered from the active screen and redeposited on the specimens has been suggested to play an important role in the nitriding mechanism involved. This paper reports a patterned deposition layer, which is in correlation with the grain orientation of polycrystalline specimens. This has provided new insights into the nitriding mechanism.

Effect of Surface Treatment and Metallic Coating on Corrosion Behavior and Biocompatibility of Surgical 316L Stainless Steel Implant

Surface engineering technology is a suitable method for coatings on the metal surfaces or performing surface modification treatment, which can improve corrosion resistance and biocompatibility of metals. In this research, corrosion behavior of Nb coating on H2SO4 and HNO3 treated AISI stainless steel 316L (SS) was evaluated. Nb coating was carried out using physical vapor deposition process on the SS. Characterization techniques including scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) technique were used to investigate the microstructure and morphology of the coated and treated SS. Electrochemical potentiodynamic tests were performed in two types of physiological solutions and compared with the pristine SS specimens. Cyclic polarization tests were performed to evaluate resistivity against pitting. Experimental results indicate that Nb coating and surface treatment of the SS had a positive effect on improvement of corrosion behavior. The decrease in corrosion current densities was significant for coated and treated specimens. The corrosion current density was much lower than the values obtained for pristine specimens.

Characterisation and Corrosion-Erosion Behaviour of Carbide based Thermal Spray Coatings

Thermal spraying has emerged as a suitable and effective surface engineering technology and is widely used to apply wear, erosion and corrosion protective coatings for various kinds of industrial applications. Cr3C2-based coatings have been applied to a wide range of industrial components. Cr3C2–NiCr coatings offer greater corrosion and oxidation resistance, also having a high melting point and maintaining high hardness, strength and wear resistance up to a maximum operating temperature of 900 °C. The corrosion resistance is provided by NiCr matrix while the wear resistance is mainly due to the carbide ceramic phase. This paper reviews the performance, developments and applications of Cr3C2–NiCr thermal spray coatings for corrosion/erosion-corrosion under different types of environments and outlines the characterization of Cr3C2–NiCr coatings with respect to their microstructure and mechanical properties, together with some brief characterisation work by the author for HVOF sprayed 75Cr3C2-25NiCr coating on T91 boiler steel.

Applications on Nanocomposite Coating Technology in Plastic Injection Mould Cavity Surface Treatment

Nano surface engineering is a protection technology using nanometer material and nanometer technology, pointing at failure forms, characteristics and mechanism, comprehensively using a variety of traditional surface engineering technology. Nanocomposite coating technology which develops on the basis of the traditional composite coating technology was briefly introduced in the article. The research of application nanocomposite coating technology in plastic injection mould cavity surface treatment has just started. The nanocomposite coating technology was compared with the ordinary nickel electro-brush coating and the basic approach which realizes nanometer on the mould cavity was described. The advantages of nanocomposite coating were comprehensively and effectively explained. It can increase the coating thickness and hardness, improve the abrasive resistance, fatigue resistance and corrosion resistance of the plastic injection mould cavity, thereby enhancing the service life of mould.

Influence of Die Lubricants on Pickling and Conversion Treatment of High‐Pressure Die‐Cast AM30 Magnesium Alloy

AbstractThe pre‐treatment of magnesium‐based components plays an important role in surface engineering technology to guarantee good adhesion of the final coating system to the magnesium substrate in order to achieve good corrosion resistance. This paper focuses on the influence of two different die lubricants—one based on mineral oil, the other on siloxane—on the pickling and conversion treatment of an AM30 alloy. The surface conditions after casting, pickling, and conversion treatment were determined by X‐ray‐induced photoelectron spectroscopy, spark erosion, optical emission spectroscopy, IR spectroscopy, and scanning electron microscopy (including EDX). The influence of the different die lubricants on the result of the pickling treatment in terms of surface morphology and composition was significant. The mineral–oil‐based lubricant was found to be removed more easily and uniformly from the surface. Only sufficient removal of the die lubricants can guarantee homogeneous and uniform formation of the conversion coating.

Microstructure and Property of Cold Sprayed Copper Coating

Cold spray is a new surface engineering technology. In this paper, pure copper particles were sprayed on the Al substrate by this method and the copper coating was deposited sucessfully on the surface of the substrate. The microstructure of the coating and the interface between the coating and the substrate were observed by optical and scanning electron microscopes, and the phase was identified by XRD for the pure copper particles and the coating. The microhardness of the coating is measured. The results show that mechanical bonding is the main mechanism for the interface between the coating and the substrate, and there is a few metallurgical bonding for the interface; the coating is dense and its porosity is less than 0.4%; XRD results indicate that there is no oxidation occurred during the spray process. The microhardness of the coating is about 160Hv, which is higher than that of the as-casted copper.

Development and Experiment of Surface Engineering Technology on Mulberry Silk Brocade Fabrics

Exploring and using surface engineering technology into the Anti-aging antibacterial mold of mulberry silk brocade fabrics through multiple dipping and padding to carry out limited permeation and effective bonding strength on material surface. It has obvious effect on antibiotic action and less effect on the silk materials’ original performance.

Tribological and corrosion testing of surface engineered surgical grade CoCrMo alloy

Abstract One of the main causes of hip prostheses failure is the premature wear of its components. Wear of metal-on-metal joints is a concern due to the toxicity and biological reaction of wear debris and metallic corrosion. The main aim of the present study was to investigate the tribological and corrosion behavior of surface engineering CoCrMo alloy. Different surface conditions were obtained on surgical grade wrought CoCrMo alloy: plasma nitrided (520 °C by 7 h at gas mixture of 10% N 2 + 90% H 2 ), PVD coated (monolayer CrN and multilayer (TiN/CrN) × 3) and modified using duplex surface engineering technology (a combination of the two previous approaches: plasma nitriding followed by plasma assisted PVD). Surfaces were characterized using scanning electron microscopy, nanoindentation, AFM and scratch test. The tribological response of the different surface conditions was studied by means of a ball-on-disc testing machine. Potentiodynamic polarization measurements were done to determine the corrosion rate. Ringer's solution was used as lubricant and electrolyte during the tribological and electrochemical tests, respectively. It was found that the duplex engineering technology enables a significant rise in the resistance of surfaces against concentrated loading modes (evaluated by scratch method); however it has no significant influence in the tribological performance of the samples during wear tests. PVD multilayer (TiN/CrN) × 3 coatings showed the higher wear and corrosion resistance whereas CoCrMo nitrided sample showed the lowest.

Classification of laser beam induced surface engineering technologies and in situ synthesis of steel matrix surface nanocomposites

A new classification of different laser beam induced surface engineering technologies is offered in this paper. An in situ laser melt injection technology is applied in this paper to modify the surface of an inexpensive carbon steel substrate. Relatively large WC+Ti particles were blown into a laser melt steel pool, and the desired (Ti,W)C carbide particles were precipitated upon cooling and solidification. Although these primary (Ti,W)C carbide particles were micrometre sized, additional nanosized (Fe,W)6C particles were found to precipitate during the subsequent heat treatment from an oversaturated steel matrix. Thus, a steel matrix surface nanocomposite was produced by the combination of in situ laser melt injection technology and subsequent heat treatment.

Direct ethanol production from hemicellulosic materials of rice straw by use of an engineered yeast strain codisplaying three types of hemicellulolytic enzymes on the surface of xylose-utilizing Saccharomyces cerevisiae cells

The cost of the lignocellulose-hydrolyzing enzymes used in the saccharification process of ethanol production from biomass accounts for a relatively high proportion of total processing costs. Cell surface engineering technology has facilitated a reduction in these costs by integrating saccharification and fermentation processes into a recombinant microbe strain expressing heterologous enzymes on the cell surface. We constructed a recombinant Saccharomyces cerevisiae that not only hydrolyzed hemicelluloses by codisplaying endoxylanase from Trichoderma reesei, β-xylosidase from Aspergillus oryzae, and β-glucosidase from Aspergillus aculeatus but that also assimilated xylose through the expression of xylose reductase and xylitol dehydrogenase from Pichia stipitis and xylulokinase from S. cerevisiae. The recombinant strain successfully produced ethanol from rice straw hydrolysate consisting of hemicellulosic material containing xylan, xylooligosaccharides, and cellooligosaccharides without requiring the addition of sugar-hydrolyzing enzymes or detoxication. The ethanol titer of the strain was 8.2g/l after 72h fermentation, which was approximately 2.5-fold higher than that of the control strain. The yield (grams of ethanol per gram of total sugars in rice straw hydrolysate consumed) was 0.41g/g, which corresponded to 82% of the theoretical yield. The cell surface-engineered strain was thus highly effective for consolidating the process of ethanol production from hemicellulosic materials.

Study on New Bimetal Floating Seal of High Speed Roller Bit Bearing

ANSYS software has been used for high speed rock bit bimetal floating seal finite element analysis, as a result, overlarge pressure of bearing seal, unreasonable pressure distribution and overlarge compression ratio of rubber ring, are main reasons for premature failure of the bearing seal. For this, the optimal design and analysis of bearing seal structure is carried out in this paper. The results showed that: the new structure of the bearing seal has effectively reduced the compression ratio of rubber ring, improved the sealing pressure distribution based on reliable sealing conditions and further reduced the sealing pressure peak. The design of dynamic metal ring flywheel lubrication groove and the application of static metal ring antifriction material surface engineering technology have obviously reduced surface friction factor and wear of metal ring, greatly improved the effectiveness and life of the seal, and further extended the bit’s life.

Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and β-glucosidase

In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying α-amylase (α-AM), glucoamylase, endoglucanase, cellobiohydrase, and β-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley β-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes.

Development of Novel Nano-Structure Functional Coatings with the Use of the Original Hybrid Device

A unique, original hybrid technological device, developed by the authors of the article, enabling the application of lots of different surface engineering methods in one technological process, including arc evaporation, ion nitriding, ion etching, ion implantation and electron beam evaporation is presented. The hybrid technological device has technical possibilities for the simultaneous realisation of different surface engineering methods in the same vacuum chamber. This results in the realization of advanced technological processes with the use of different surface engineering methods for forming the coating’s properties in one multi-stage technological process. Different surface engineering methods use different plasma sources and different methods of the atmosphere creation and often require different supply and control systems. A possibility of combining a few different surface treatment methods in one technological process is provided by a unique hybrid device. Selected applications of hybrid surface engineering technologies executed with the use of this original hybrid device, i.e. creation of the nano-multilayer and nano-composite Cr/Ni-Cr3C2coatings increasing the erosion wear resistance and creation of multi-layer coatings with increased thermal resistance – Thermal Barrier Coating (TBC) are presented

Molecular Breeding of Advanced Microorganisms for Biofuel Production

Large amounts of fossil fuels are consumed every day in spite of increasing environmental problems. To preserve the environment and construct a sustainable society, the use of biofuels derived from different kinds of biomass is being practiced worldwide. Although bioethanol has been largely produced, it commonly requires food crops such as corn and sugar cane as substrates. To develop a sustainable energy supply, cellulosic biomass should be used for bioethanol production instead of grain biomass. For this purpose, cell surface engineering technology is a very promising method. In biobutanol and biodiesel production, engineered host fermentation has attracted much attention; however, this method has many limitations such as low productivity and low solvent tolerance of microorganisms. Despite these problems, biofuels such as bioethanol, biobutanol, and biodiesel are potential energy sources that can help establish a sustainable society.

Deposition of Nano Sized Titanium Nitride on H11 Tool Steel Using Active Screen Plasma Nitriding Method

Active screen plasma nitriding (ASPN) is an emerging surface engineering technology that offers many advantages over the conventional DC plasma nitriding (DCPN). In this research, plasma nitriding of H11 tool steel, using titanium active screen was investigated. Samples were plasma nitrided at 550oC, for 10 and 20 h with 3 different gas mixtures of H2/N2% = 3, 4, 5. The coating microstructure and phase analysis were investigated using Scanning Electron Microscopy (SEM) and X-ray Diffraction techniques. The dominant phase in the compound layer was TiN. With increasing processing time, the layer thickness was increased. According to SEM results, the sample surface was formed of nano sized and particulate titanium nitride particles. It was shown that with increasing H2% in gas mixtures, better surface quality, golden yellow color, was obtained. Also, the intensity of TiN peaks and layer thickness were increased significantly.

Remanufacturing of High Temperature Ball Valve by Surface Engineering Technology

Four kinds of coating materials and two kinds of brush plating materials were screened and sprayed on the surface of valve ball by plasma spraying technology and brush plated on the surface of valve seat by electrical brush technology, respectively. The wear resistance of the sealing pairs and the properties of the plasma sprayed coatings were tested. The results indicate that the sealing pair composed of the valve ball with the plasma sprayed coating of Al2O3-TiO2 and the valve seat with the brush plating layer of nickel tungsten has best combination property. The gap of the sealing pair at room temperature and the leakage rate at elevated temperature of the high temperature ball valve were obtained by FEM method and analysis method, respectively. Therefore, the open and close torque of the high temperature ball valve was determined. According to the results of the research, the failed ball valve was remanufactured, and the performance inspection was also conducted. The remanufactured ball valve has much longer service life than the original one and its sealing behavior was also improved significantly.

IMMUNOHEMATOLOGY: Novel antibody screening cells, MUT+Mur kodecytes, created by attaching peptides onto red blood cells

BACKGROUND: Antibody screening and identification panels are generally limited by the natural antigenic phenotypes present in their source donor population. However, the recent ability to attach peptides to the surface of cells has opened up the opportunity to create red blood cells (RBCs) with antigen profiles specifically designed for antibody screening and identification in a target population.STUDY DESIGN AND METHODS: Clinically significant antibodies to variant glycophorins (GPs) such as GP.Mur are more commonly seen in certain Asian populations. Using peptides representative of the MNS antigens MUT and Mur, RBC antibody screening cells were created using KODE cell surface engineering constructs. MUT‐, Mur‐, and MUT+Mur‐modified RBCs, known as kodecytes, were tested against monoclonal reagents and polyclonal sera with specificity for epitopes on GP.Mur‐positive RBCs.RESULTS: Kodecytes retained their normal expression of intrinsic blood group antigens while expressing the new epitopes attached by KODE technology. The MUT, Mur, and MUT+Mur kodecytes, although unreactive with the various monoclonal reagents, were appropriately reactive with polyclonal sera containing antibodies reactive with GP.Mur‐positive RBCs.CONCLUSIONS: This study used selected MUT and Mur peptides and KODE cell surface engineering technology to create MUT+Mur kodecytes suitable for the detection and identification of RBC antibodies in human serum or plasma. This technology has the potential to create a large range of specialized RBCs for antibody screening and identification.