Metallocene of zirconium were used as a catalyst for an insertion polymerization of 1-methylsilene directly into pre-ceramic precursor polyzirconocenecarbosilane (PZCS) during dechlorination of dichlorodimethylesilane by sodium, which exhibits high catalytic effectiveness with the maximum conversion ratio of polycarbosilane up to 91%. The average molecular weights of polymers synthesized are le...

OBJECTIVES To evaluate the effect of silane application and silane heat treatment on lithium-disilicate ceramic when bonded to composite resin. METHODS Twelve blocks of lithium-disilicate (LD) ceramic were fabricated and bonding surfaces were etched using 9.5% hydrofluoric acid (90 seconds). Three experimental groups resulted from the various surface treatment combinations, which included, no...

We have developed a novel composite film fabrication process that utilizes the soft lithographic approach, Particle Replication in Nonwetting Templates (PRINT). This process was found to be a very viable approach to the fabrication of well-structured, multifunctional polymer composite thin films. Particle aggregation was completely eliminated as discretely molded particles with specific shape, ...

A surface layer of a ceramic substrate can be modified by introducing a second phase into a melt pool generated locally by a laser beam. CuO, WO3 powders with nanosized particles were used to alloy alumina and a glass ceramic LTCC (Low Temperature Co-fired Ceramic). Depending on the process parameters the nano-particles were melted during the laser process and solidified during cooling in the c...

OBJECTIVE Increased number of adult patients requesting orthodontic treatment result in bonding bracket to ceramic restorations more than before. The aim of this study was to evaluate and compare the shear bond strength of orthodontic brackets bonded to two types of ceramic bases with conventional orthodontic bonding resin and a new nano-filled composite resin. MATERIALS AND METHODS Twenty fo...

The microwave heating of a ceramic composite is modelled and analysed. The composite consists of many small ceramic particles embedded in a ceramic cement. The composite is assumed to be well insulated, and each particle is assumed to be in imperfect thermal contact with the surrounding cement. Based on these two assumptions an asymptotic theory exploiting the small Biot number and small non-di...

STATEMENT OF PROBLEM Ceramics are widely used for anterior restorations; however, clinical color reproduction still constitutes a challenge particularly when the ceramic crowns are used on titanium implant abutments. PURPOSE The purpose of this in vitro study was to investigate the effect of implant abutment material on the color of different ceramic material systems. MATERIAL AND METHODS F...

Coated powder particles composed of a ceramic core and a metallic coating are being considered for plasma spray applications. The goal of using these powders is to produce particulate-reinforced metal-matrix composite coatings. In this work, the feasibility of plasma spray processing in producing these composite coatings is evaluated. A numerical model is presented to analyze the in-flight ther...

In this paper the principle and experimental process of the infrared thermal wave nondestructive testing (NDT) on carbon fiber reinforced silicon carbide (Cf /SiC) ceramic matrix composite sample are demonstrated. The experiment results compared with X-ray testing results show that the infrared thermal wave NDT is an effective method for the Cf /SiC ceramic matrix composite, and it can be used ...

A multilayer ceramic actuator composed of piezoelectrically active Pb(Zn1/3Nb2/3)0.2–Pb(Zr0.5Ti0.5)O0.8 (PZN–PZT) layers and electrically conducting PZN–PZT/Ag layers was fabricated by the co-extrusion process. For the piezoelectric layers, PZN–PZT, which is sinterable at a low temperature (9001C), was used. For the conducting layers, a PZN–PZT/Ag composite, made by mixing silver particles with...