OBJECTIVE The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). MATERIALS AND METHODS From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bot...

A commercial hardness testing machine was provided to represent a hardness reference standard in Slovenia. In order to evaluate how accurate the hardness scales realised with this machine could be, the main influence factors contributing to the uncertainties were verified and comparative measurements carried out, the results of which were compared with several laboratories owning primary hardne...

in this study, friction stir spot welding (fssw) is applied to join the tial6v4 titanium alloy with 1.5 mm thickness and then the effect of rotational speed and tool dwell time on microstructure and mechanical properties is investigated. in this regard, the speed of the tool rotation was considered as 800, 1000, and 1200 rpm, as well as the tool dwell time was set at 7 and 12s. microstructural ...

The present experimental investigations deal with the improvement of mechanical properties of cold work tool steels through different heat treatment processes. An attempt was made to get optimal combination of hardness and toughness through changes of microstructure by heat treatment. The toughness of D2 tool steel increases with tempering temperature. The hardness of D2 tool steel decreases wi...

functionally graded aluminium/zirconia metal matrix composite was fabricated using stir casting technique followed by horizontal centrifugal casting process and a hollow cylindrical functionally graded composite (150 x 150 x 16 mm) was obtained with centrifuging speed of 1200 rpm. the microstructural evaluation and hardness test was carried out on the outer and inner surface of the functionally...

introduction one of the limitations of tissue conditioners (tc) is gradual hardening of the material in a short time period after insertion in the mouth, due to the loss of their viscoelastic properties. the aim of this study was to determine the softness of two different tissue conditioners with and without the monopoly coating. methods and materials in this experimental study, acropars and vi...