Effect of Different Titanium Surface Treatments on the Adhesion Test Result:Dental Application

The aim of the study was to investigate the effect of different surface treatment of titanium(Ti)on the adhesion test results for dental application.Ti substrates roughened by 400 to 1500-grit SiC polish papers and alumina blasting,alkali treated by 5 molar(M)NaOH and KOH solutions and heat treated at the temperature range of 400-800℃were used in this study.The treated samples were subjected to the adhesion test.According to the results of the adhesion test,the adhesive strength showed the highest value for the blasted titanium among all polished and blasted samples.The Ti samples heated at 650℃showed the highest adhesive strength among all heat-treated samples.Further,the adhesion test results indicated the higher adhesive strength of chemically treated samples treated by NaOH rather than that by KOH.The polished and heated Ti samples showed the highest adhesive strength among all samples.

Surface Treatments Effect on Rainfall Canopy Interception and Runoff-Rainfall Ratio for in-Field Rainwater Harvesting

The purpose of this study was to ascertain the effectiveness of surface treatments to quantify the partitioning of rainwater falling on the runoff strips and basins as well as to determine the fraction of rainwater available to intercept by maize canopy and infiltrate into the root zone. The rainfall canopy interception （RCI） was estimated as a function of basin leaf area ratio per rain event. The runoffrainfall （RR） ratio was determined for both a single rainfall event and the whole growing season. Infiltration ratio of basin to runoff area was analysed for every unit millimeter of water that infiltrate in the runoff section, some additional of water will infiltrate in the basin area. The plateau value of RCI-rainfall relationships rendered about double in the wider （1.0-1.1 mm） compared to the narrow runoff strips （0.5-0.6 mm）. Statistically, the combined surface treatments （RSL x ML） affected the RR ratio with higher efficiency in bare 1 m runoff （27%） and the lower efficiency group （〈 10%） is associated with the widest runoff length covered with mulch. Variations in fractions of rainwater that can infiltrate into basins and runoffareas can lead one to select alternative strategies for water harvesting techniques.

Influence of Different Surface Treatments of H13 Hot Work Die Steel on Its Thermal Fatigue Behaviors

Thermal fatigue checking is the general failure of hot work die steels, which is relative with the structures and properties of the steels and the stress alternated during the employment. The Uddeholm test method on thermal fatigue is used to compare the behaviors of different samples, which are treated with plasma nitriding、plasma sulfur carbon nitriding、boronizing or not treated. The results show that the nitriding improves the thermal fatigue property of the tool steel, while the plasma sulfur carbon nitriding and the boronizing impair the property. The mechanisms are induced as follows. By increasing the hardness and changing the stress distribution in the surface layer, surface treatment can decrease the plastic deformation and the tensile stress during the cycling. Therefore, the generation and growth of the cracks are restrained. On the other hand, as results of surface treating, in the surface layer the toughness declines and the expanding coefficient ascendes; the latter change caused the strengthening of the tensile and compressive stress during the cycling. Thus the resistance to thermal fatigue is weakened. Whether or not the surface treatment is favor to thermal fatigue of tool steels relies on which factor is dominant.

Study on Surface Treatments on CdSe Wafers

The surface treatments on CdSe wafers were studied by means of SEM,XPS and micro-current test instrument.The relations between electrical properties of CdSe wafers and surface topography,composition and structure were analyzed.The results show that the change of surface composition by etching is beneficial to decrease leakage current.Meanwhile,the increase of oxygen on surface caused by passivation can largely decrease leakage current.When passivating time is 40 min,the wafers surface appears smooth and compact,which will decrease the density of surface state,the optimal electrical property of the wafer is therefore obtained.

Chrome free surface treatments for galvanized steels—present and future

As the galvanized steels used for electrical and office appliances has achieved a complete chrome-free production worldwide,surface treatment technologies have entered a new phase of development.Grenter effort will be made in exploring new frontier for future surface treatment technologies.A greater contribution will be made for environmental protection,energy-saving and resource-saving,to prevent globalwarming.

Influence of surface treatments on fatigue life of a two-stroke free piston linear engine component using random loading

This paper describes the finite element (FE) analysis technique to predict fatigue life using the narrow band frequency response approach. The life prediction results are useful for improving the component design methodology at the very early development stage. The approach is found to be suitable for a periodic loading but requires very large time records to accurately describe random loading processes. This paper is aimed at investigating the effects of surface treatments on the fatigue life of the free piston linear engine’s components. Finite element modelling and frequency response analysis were conducted using computer aided design and finite element analysis commercial codes, respectively. In addition, the fatigue life prediction was carried out using finite element based fatigue analysis commercial code. Narrow band approach was specially applied to predict the fatigue life of the free piston linear engine cylinder block. Significant variation was observed between the surface treatments and untreated cylinder block of free piston engine. The obtained results indicated that nitrided treatment yielded the longest life. This approach can determine premature products failure phenomena, and therefore can reduce time to market, improve product reliability and customer confidence.

Effects of surface treatments of galvanized steels on projection welding procedure

A group of projection welding experiments and joints tension-shear tests are carried out for cold-rolled steel sheets, galvanized steel sheets (GSS) without treatment, GSS with phosphating and GSS with surface greasing, respectively. The experimental results are regressively analyzed on the computers, then the projection welded joint tension-shear strength curve and the perfect welding currents range of each material are obtained. The results show that surface treatments of galvanized steels have effects on their spot weldabilities. Among the four kinds of materials, GSS with surface greasing have the worst spot weldability, for they need higher welding current and have a narrow welding current range.

Attaching Organism Community Characteristics of Different Surface Treatments on Artificial Reef Tem-plates Inshore of Yuanzhou Island

In order to understand the biological community characteristics of different surface treatments of ＇artificial reef templates ,which had been placed on the offshore, Yuanzhou island, Daya Bay. Sampling survey was taken in August of 2014. The results showed that 39 species of fouling organisms were collected and iden- tiffed, Ostrea nigromarginata has attached the absolute position of the dominant species ; Through the concrete block surface treatment has a better biofouling effect, and red brick, granite plates and no-surface-treated concrete template attached biomass and abundance of organisms were very low ; Biomass and abundance indices and ecological indices do not show a certain degree of regularity.

Effects of substrate surface treatments on hybrid manufacturing of AlSi7Mg using die casting and selective laser melting

To balance the manufacturing cost and customizability of automotive parts,a hybrid manufacturing process combining die-casting and selective laser melting(SLM)is proposed:starting with a conventional cast substrate,SLM is utilized to add additional geometric elements on top of it.For this hybrid process,the first priority is to prepare a substrate surface suitable for the subsequent SLM addition of the top-on elements.In this study,the original cast surface of AlSi7Mg was processed by sandblasting,wire electro-discharge machining,and laser remelting,respectively.Then,additional AlSi7Mg components were built on both the original cast and treated surfaces through SLM.After hybrid builds,these surfaces and resultant interfaces were examined by optical and scanning electron microscopes.Results indicate that the defect-free metallurgical joint between the cast and additively added parts can be formed on all surfaces except for the one processed by electro-discharge machining.The observed epitaxial grain growth crossing the interface implies a strong connection between the cast and the SLMed component.Despite these benefits,also mismatches in microstructure,residual stress level and element distribution between the two parts are identified.After a comprehensive assessment,laser remelting with no additional machining is recommended as the optimal surface treatment preceding SLM fabrication,because of its user-friendly operation,low cost,and high industrial feasibility.

Nickel-based superalloy architectures with surface mechanical attrition treatment: Compressive properties and collapse behaviour

Surface modifications can introduce natural gradients or structural hierarchy into human-made microlattices,making them simultaneously strong and tough.Herein,we describe our investigations of the mechanical properties and the underlying mechanisms of additively manufactured nickel–chromium superalloy(IN625)microlattices after surface mechanical attrition treatment(SMAT).Our results demonstrated that SMAT increased the yielding strength of these microlattices by more than 64.71%and also triggered a transition in their mechanical behaviour.Two primary failure modes were distinguished:weak global deformation,and layer-by-layer collapse,with the latter enhanced by SMAT.The significantly improved mechanical performance was attributable to the ultrafine and hard graded-nanograin layer induced by SMAT,which effectively leveraged the material and structural effects.These results were further validated by finite element analysis.This work provides insight into collapse behaviour and should facilitate the design of ultralight yet buckling-resistant cellular materials.

Evaluation of the performance of surface treatments on concrete durability

This paper reports on a laboratory-based study carried out to evaluate the effectiveness of surface treatments on the durability of concrete and suggests a number of different evaluation methodologies for assessing the performance of various surface treatments. Durability of untreated and treated concrete specimens was evaluated by measuring chloride diffusion,charge passing capacity,air permeability and water absorption. A total of six concrete surface treatments were selected to represent different generic types,including coating,penetrant and mixed-use treatments. Results show that the concrete specimens with a coating procedure have a better long-term performance and effectiveness than the specimens with the penetrant treatments. This work also indicates that the wetting and drying cycles test can be used to assess the weatherability of the surface treatments. The ASTM C 1202 and the Autoclam air permeability test can be used to evaluate the effectiveness of surface treatments quantitatively. Further work is needed,however,to assess the longevity of the various surface treatments.

Effects of Surface Treatments on Tensile, Thermal and Fibre-matrix Bond Strength of Coir and Pineapple Leaf Fibres with Poly Lactic Acid

Coir Fibres （CF） and Pineapple Leaf Fibres （PALF） are valuable natural fibres which are abundantly available in Malaysia as agricultural wastes. The aim of this study is to investigate the effects of alkali （6%）, silane （2%）, and calcium hydroxide （6%） on tensile, morphological, thermal, and structural properties of CF and PALF to improve their interfacial bonding with Polylactic Acid （PLA） matrix. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to observe the effectiveness of the chemical treat- ments in the removal of impurities. Alkali treated fibres yield the lowest fibre diameter and the highest Interfacial Stress Strength （IFSS）. Thermogravimetric Analysis （TGA） shows improved thermal stability in silane treated CF and alkali treated PALF. It is assumed that fibre treatments can help to develop biodegradable CF and PALF reinforced PLA biocomposites for industrial applications.

CHEMICAL PRETREATMENTS OF THE SURFACE OF WC-15wt%Co WITH DIAMOND COATINGS

Diamond films were deposited on the cemented carbide WC-15%Co substrates by a hot-filament chemical vapor deposition (HF CVD) reactor. The substrate surfaces were chemically pretreated by the following two-step etching method: first using Murakami reagent for 1-3 min, and second using an HNO3:HCl=1:1 solution for 10-40 min. It is indicated that the Co content of the substrate surfaces could be reduced from 15% to 0.81-6.04% within the etching depth of 5-10μm, the surface roughness of the substrates was increased up to Ra=1.0μm, and the substrates hardness was decreased from 89.0 HRA to 83.0 HRA after the two-step etching. It is observed that the morphologies of the diamond films on the WC-15%wt Co substrates emerge in various shapes. The indentation testing shows that the good adhesion between diamond film and the substrate after HF CVD deposition could be obtained.

Elaborating Polyurethane Pillowy Soft Mat on Polypropylene Monofilament Surface with Stepwise Surface Treatments

The dissatisfactory mechanical compliance between stiff polypropylene(PP)and soft human tissue is one of the main factors causing the implanted complication of PP mesh devices such as chronic abdominopelvic pain and mesh exposure.This work aims to improve the mechanical compliance of PP monofilament to human tissue without compromising the mechanical properties by elaborating polyurethane pillowy soft mat on the PP monofilament surface.Combining polarity pretreatment with dopamine-sedimentation,stiff PP monofilament can be wrapped up facilely and tightly in soft polyurethane to obtain PU/PP complex fiber with a core-shell structure.Notably,the interfacial shear strengths(IFSS)between stepwise treated PP monofilament and PU mat can effectively increase 586%compared to raw PP.This work provides a promising surface modification strategy to improve the interfacial adhesion between PP monofilament and PU mat.The obtained novel PU/PP complex fiber with pillowy soft mat would be a potential application in abdominal wall defects,hernia repair and pelvic organ prolapsed surgery.

Enhanced initial biodegradation resistance of the biomedical Mg-Cu alloy by surface nanomodification

Mg-Cu alloys are promising antibacterial implant materials.However,their clinical applications have been impeded by their high initial biodegradation rate,which can be alleviated using nanotechnology by for example surface nanomodification to obtain a gradient nanostructured surface layer.The present work(i)produced a gradient nanostructured surface layer with a∼500µm thickness on a Mg-0.2 Cu alloy by a surface mechanical grinding treatment(SMGT),and(ii)studied the biodegradation behavior in Hank's solution.The initial biodegradation rate of the SMGTed samples was significantly lower than that of the unSMGTed original counterparts,which was attributed to the surface nanocrystallization,and the fragmentation and re-dissolution of Mg_(2)Cu particles in the surface of the SMGTed Mg-0.2 Cu alloy.Furthermore,the SMGTed Mg-0.2 Cu alloy had good antibacterial efficacy.This work creatively used SMGT technology to produce a high-performance Mg alloy implant material.

Surface treatment effect on the photocatalytic hydrogen generation of CdS/ZnS core-shell microstructures

CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compared with those of CdS or ZnS spherical particles.CdS/ZnS photocatalysts with different amount of ZnS loaded as shells were prepared by adjusting the concentrations of Zn and S precursors during synthesis.The optical properties and photocatalytic activity for hydrogen production were investigated and the amount of ZnS loaded as shell was optimized.Thermal annealing and hydrothermal sulfurization treatments were applied to the core-shell structure and both treatments enhanced the material＇s photocatalytic activity and stability by eliminating crystalline defects and surface states.The result showed that thermal annealing treatment improved the bulk crystallinity and hydrothermal sulfurization improved the surface properties.The sample subjected to both treatments showed the highest photocatalytic activity.These results indicate that CdS/ZnS core-shell microspheres are a simple structure that can be used as efficient photocatalysts.The hydrothermal sulfurization treatment may also be a useful surface treatment for metal sulfide photocatalysts.The simple two-step method provides a promising approach to the large-scale synthesis of core-shell microsphere catalysts.

Deformation and fracture behavior of commercially pure titanium with gradient nano-to-micron-grained surface layer

Titanium with gradient nano-to-micron scale grains from surface to matrix was fabricated by surface mechanical grinding treatment(SMGT) at room temperature.The SMGT-treated titanium shows higher strength than that of as-received one,but moderate ductility between those of ultra-fine grained(UFG) and coarse-grained titanium.Tensile stress-strain curves of SMGT-treated titanium show double strain hardening regimes.The strain hardening rate(dσ/dε) decreases with increasing strain in tensile deformation.The high strain hardening rate at initial yielding is attributed to nano-to-micron-grained surface layer.The low strain hardening rate at large plastic strain regime primarily results from coarse-grained matrix.The SMGT-treated titanium shows a ductile fracture mode with a large number of dimples.The small size of dimples in the treated surface layer is due to the combination of the high strength and strain hardening exponent.The difference between dimple size in nano-to-micron-grained surface layer and coarse-grained matrix is discussed in terms of plastic zone size at the tip of crack in the SMGT-treated titanium.

Study on the Effect of Surface Modification on the Mechanical and Thermal Behaviour of Flax,Sisal and Glass Fiber

Natural fiber-reinforced hybrid composites can be a better replacement for plastic composites since these plastic composites pose a serious threat to the environment.The aim of this study is to analyze the effect of surface modification of the natural fibers on the mechanical,thermal,hygrothermal,and water absorption behaviors of flax,sisal,and glass fiber-reinforced epoxy hybrid composites.The mechanical properties of alkaline treated sisal and flax fibers were found to increase considerably.Tensile,flexural and impact strength of glass/flax-fiber-reinforced hybrid samples improved by 58%,36%,and 51%,respectively,after surface alkaline treatment.In addition,the hygrothermal analysis and water absorption capacity are studied and also the Interfacial bonding properties were analyzed using Scanning Electron Microscopic images.The thermal analysis using thermogravimetric analyzer reveals that the decomposition temperature for hybrid fiber reinforced composites are between 306 and 312℃.In conclusion,surface treatment improves the performance of natural fiber in hybrid fiber-reinforced composites,particularly flax fiber.

A large-scale cold plasma jet: generation mechanism and application effect

Atmospheric pressure cold plasma jets(APCPJs) typically exhibit a slender, conical structure,which imposes limitations on their application for surface modification due to the restricted treatment area. In this paper, we introduce a novel plasma jet morphology known as the large-scale cold plasma jet(LSCPJ), characterized by the presence of both a central conical plasma jet and a peripheral trumpet-like diffuse plasma jet. The experimental investigations have identified the factors influencing the conical and the trumpet-like diffuse plasma jet, and theoretical simulations have shed light on the role of the flow field and the electric field in shaping the formation of the LSCPJ. It is proved that, under conditions of elevated helium concentration, the distributions of impurity gas particles and the electric field jointly determine the plasma jet’s morphology. High-speed ICCD camera images confirm the dynamic behavior of plasma bullets in LSCPJ, which is consistent with the theoretical analysis. Finally, it is demonstrated that when applied to the surface treatment of silicone rubber, LSCPJ can achieve a treatment area over 28 times larger than that of APCPJ under equivalent conditions. This paper uncovers the crucial role of impurity gases and electric fields in shaping plasma jet morphology and opens up the possibility of efficiently diversifying plasma jet generation effects through external electromagnetic fields. These insights hold the promise of reducing the generation cost of plasma jets and expanding their applications across various industrial sectors.