The surfaces of hydoxyapatite ceramics were modified by the precipitation of octacalcium phosphate coating from aqueous solution and the biomimetic method synthesized nanohydroxyapatite coatings. Both coatings were deposited as continuous and uniform layers. It was demonstrated that the octacalcium phosphate coating was inappropriate for in-vitro osteoblast proliferation despite of good initial...

This paper presents the coating thickness effect on the stress distribution of a coated cylinder head. A typical thermal barrier coating was applied on a diesel engine cylinder head. Thus, the residual stress which occurred during the plasma thermal spraying was also considered. The coating system consisted of two layers a metallic bond coat and a ceramic top coat. The bond coat thickness is co...

Ceramic insulators are widely used in transmission as well as in distribution lines. As outdoor insulators, the ceramic insulators are subjected to environmental stresses. In particular case, the insulators may severe high pollution exposure. Under the polluted condition, high leakage current will flow on the insulator surface and dry band arching may take place. The phenomena may initiate the ...

Calcium phosphate (Ca-P) coatings on zirconia bone implants have a great potential to improve the osseointegration of already existing ceramic implants, owing to their bone-bonding ability and high osteoconductive characteristics. In our study, we have prepared three different kinds of Ca-P coatings, namely the octacalcium phosphate (OCP), hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP)...

An analysis is made of contact damage in brittle coatings on metal substrates, using a case study of a dental porcelain coating of thickness between 0.1 and 1 mm fused onto a Pd alloy base, with spherical indenter of radii 2.38 and 3.98 mm. At large coating thicknesses (>300 mm), the first damage takes the form of surface-initiated transverse cone cracks outside the contact. At small coating th...

OBJECTIVES This study evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to six commercial dental ceramics. METHODS Six disc shaped ceramic specimens (glass ceramics, glass infiltrated alumina, glass infiltrated zirconium dioxide reinforced alumina) were used for each test group yielding a total number of 216 specimens. T...

This study focuses on the effect of surface coating on the impellers and diffusers in improving the efficiency of mixed flow submersible borewell pumps. It consists of two parts. In the first part, a 3 stage pump was constructed with uncoated bronze impellers and cast iron diffusers having a surface roughness value of 2.5μm Ra and tested for pump performance. Then the same 3 stage pump was test...

A development project was carried out at DESY, aimed at reducing secondary electron emission and multipactor effects in TESLA couplers by TiN layers generation on surfaces which were not protected in this way previously. Thin TiN films on ceramic or metallic surfaces were produced by deposition from Ti vapor in low pressure ammonia. Selection of processing parameters and their effect on multipa...

The aim of this study was to qualitatively demonstrate surface micro-morphological changes after the employment of different surface conditioning methods on high-alumina and glassy-matrix dental ceramics. Three disc-shaped high-alumina specimens (In-Ceram Alumina, INC) and 4 glassy-matrix ceramic specimens (Vitadur Alpha, V) (diameter: 5 mm and height: 5 mm) were manufactured. INC specimens wer...

The specific outputs of some diesel engine applications have produced thermal loadings in excess of the strength of typical aluminium piston alloys. Functionally graded coatings are used to increase performances of high temperature components in diesel engines. Thermal barrier coating are being evaluated to return the components durability to acceptable levels as well as providing a means of lo...