Die casting process is used since long, but even today problems like erosion, corrosion, soldering and sticking affect die life. These dies undergo thermal cyclic loads from 70 oC to 600 oC during processing. Physical Vapor Deposition (PVD) hard coating can play an important role in such extreme applications. In the present work, we report the use of Chromium based multila...

Magnesium alloys have great potential for developing orthopedic implants due to their biodegradability and mechanical properties, but the rapid corrosion rate of the currently-available alloys limits their clinical applications. To increase the corrosion resistance of the substrate, a protective ceramic coating is constructed by a micro-arc oxidation (MAO) process on ZK60 magnesium alloy. The p...

Poor corrosion resistance is one of the main disadvantages for biodegradable magnesium-based metals, especially applied for bone fixation, where there is a high demand of bio-mechanical strength and stability. Surface coating has been proved as an effective method to control the in vivo degradation. In this study a Ca-P self-sealing micro-arc oxidation (MAO) coating was studied to verify its ef...

Titanium (Ti) and Ti-based alloy are widely used in the biomedical field owing to their excellent mechanical compatibility and biocompatibility. However, the bioinert bioactivity and biotribological properties of titanium limit its clinical application in implants. In order to improve the biocompatibility of titanium, we modified its surface with TiOx/TiNx duplex composite films using a new met...

To add biocompatibility or biofunction to metal surface, an intelligent interface between metals and tissues must be acquired. Tremendous surface modification techniques are currently studied to create the intelligent interface. In particular, bone formation or bone bonding is major purpose of the surface modifications. Time transient of surface modification techniques are summarized and the im...

To evaluate the effects of micro-arc oxidation (MAO) coating on the outcomes of a grit-blasted tapered-wedge stem in total hip arthroplasty (THA), we performed a retrospective review of 141 THAs using MAO coated stem for a minimum of 5years and compared them to 219 THAs using the same geometry stem without MAO coating. Harris hip score improved from 43.7 points preoperatively to 93.9 points pos...

Porous TiO2 films were prepared by the micro-arc oxidation (MAO) of Ti plates, and their CO sensing properties at low concentrations (5–100 ppm) were investigated as an application for an air quality control sensor. The obtained rutile films exhibited the maximum CO gas response at 350 ◦C, which is typical for semiconductor-type gas sensors, and the Ra/Rg was ∼1.6 for 10 ppm CO (Ra: resistance ...

Micro-arc oxidation (MAO) ceramic coatings were formed on TC4 alloy surface in silicate and metaphosphate electrolytes based with K₂ZrF₆ for various concentrations. X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) were used to characterize the phase composition, microstructure and chemical compositions of the coatings. The infrared emissivity o...

background and aims. newer curing units such as plasma arc can polymerize the sealants in much shorter curing times. the aim of this study was to compare the effect of two different curing units on the micro-leakage of a fissure sealant material. materials and methods. sixty two extracted premolars without caries were randomly divided into two groups of 31 samples. occlusal surfaces of all teet...

A micro-channel heat exchanger reactor with different micro-baffle shapes has been studied numerically. Governing equations were solved base on the finite volume method with FLUENT software. In upper section, oxidation reaction of methanol was occurred and in lower section, steam reforming of methanol was done. Two sections were separated with solid part which played as heat exchanger and trans...