Because of large industrial development which the world has seen in
all fields. scientists and researchers aim to produce new materials
that having special engineering properties with low economic cost as
fit multiple industrial application and us
es. So in This present
article We try to prepare composite materials based on aluminum
alloy (6663) and reinforcement it by different particles having size
of micron of Alumina and silicon carbide particles are added in
specific weight parentage by stir casting
technique to obtain Aluminum Which having the improving
mechanical properties
Introduction :The demand for posterior aesthetic restorations has dramatically
increased in recent years. Several new materials have been developed with improved
aesthetic, adhesive and mechanical properties.
Theoretically, nano-structured dental
resin omposites are purported to have increased
wear and hardness resistance compared with hybrid composites and may favor the
achievement of restoratives with better long-term performance.
Aim: The wear resistance of different types of resin composites were evaluated in
the in vitro study.
Material and methods :Two nanohybrid restorative composites -Tetric®EvoCeram
(Ivoclar-Vivadent) and CeramXTM(Dentsply) - were compared with a microhybrid
material - Tetric®Ceram (Ivoclar-Vivadent) and hybrid material Spectrom (Dentsply) .
wear resistance : fifteen specimens (3x3 mm) of each material were subjected to
wear tests .
The data were analyzed by 1-way ANOVA(<=0.5).
Results :
The Tetric®EvoCeram composite resin exhibited significantly less wear than the
CeramX and Tetric®Ceram material .
Conclusions :In terms of wear resistance, nano-structured composites may perform
either similarly or comparatively
better than a microfilled and hyprid composite .
nanohybrid restorative composites can thus be considered as a good restorative
material.
In this research work, an epoxy polymer- Carbon Black composite has been
prepared and characterized regarding the effects of adding carbon black to
epoxy polymer on some structural properties such as polymerization behavior,
cross-linking reaction
time and yield and some properties e. g. glass transition
temperature (Tg), Young modulus (E) and flexural strength (σ).
The cross-linking reaction and glass transition temperature were studied by
Differential Scanning Calorimetry (DSC), and the mechanical tests were done
by Universal Testing Machine.
In this work, Rheological and mechanical properties of acrylonitrile –
butadiene – styrene/ corn starch composites (ABS/starch) were studied. The
composites were prepared using a laboratory scale single screw extruder.
Rheological properties were
determined using the single screw extruder, and
apparent shear rate (γ), apparent shear stress (τ), apparent viscosity (η), non-
Newtonian index (n) and flow activation energy at a constant shear rate (Eγ)
and constant shear stress (Eτ) were determined. Mechanical properties in term
of tensile tests were performed using Testometric M350-10KN, stress at break,
strain at break and Young's modulus were determined. Rheological results
showed that the composites are pseudo plastic in behavior, and the apparent
viscosity of the composites increases with increasing starch content above the
additive rule which indicates a partial compatibility in the composite, also it
was found that the flow activation energy of the composite increases with
increasing starch content. Also it was found that the activation energy value at
a constant shear stress is more than that at a constant shear rate. The
mechanical results showed that the strain at break of the composite decreases
sharply by the presence of starch, whereas the young's modulus increases with
increasing starch content.
