in this study, aluminum (al) matrix reinforced with micro-particles (30 µm) and nano-particles (50 nm) boron carbide (b4c) were used to prepare al-2.5%wt., b4c nano-composite and micro-composite, respectively, using mechanical alloying method. the mixed powders were mechanically milled at 5, 10, 15 and 20 hrs. the xrd results indicated that the crystallite sizes of both the micro-composite and ...

this paper investigates axial compression process of multi-layered tubes with circular cross-section under the axial loading in the quasi-static condition using experimental method. some specimens are prepared in seven different groups, namely; empty carbon/epoxy composite tubes, solid carbon/epoxy composite rods, empty copper tubes, composite tubes with silicon sealant filler, concentrically s...

background: although composite restorations are really valuable for esthetic zones, they have shown less longevity rather than amalgam restorations. since it may be related to the method used for curing the composite, postcuring could increase the degree of conversion and result in more long‑lasting composite restorations. this study was planned to evaluate the effect of two different postcurin...

statement of problem: the bond strength between restorative material and tooth structure is so important for conduction of durable restoration. considering the recent attention to low shrinkage composite resins, evaluation of micro tensile bond strength of these materials would be valuable. objectives: to compare the microtensile bond strength of silorane composite resin (filtek p90) with the c...

aluminum base composite materials with variable properties which have been strengthened by alb 2 particles have been widely used. in this study, composites with variable properties of al-5%b and al-2%mg-2%b which are produced through centrifugal casting are investigated as far as their microstructure and hardness are concerned. the microstructure of these composite were studied by using metallo...

Aims: This study was performed to compare microleakage in class II composite restorations with flowable composites and dual cure composite resin as intermediate material and also to evaluate the effect of delayed light polymerization of dual cure composite base on microleakage. Materials and methods: Class II box cavities were made with air water spray and divided into four groups. Group 1 was ...

composite electrodeposition is a low-cost and low-temperature method, which is used to make metal matrix composite coatings. in this study the surfactant of anionic(sds) and cationic (ctab) is used as additive in composite coating of ni/tin. the results showed that the anionic surfactant caused more particles in the composite coatings. increasing sds concentration to the optimal value leads to ...

background: repair bond strength of different composite resins has been assessed in few studies. in addition, reports on the effi cacy of surface treatments are debated. therefore, this in vitro study was conducted to evaluate the effect of three surface treatments on two nanocomposites versus a microhybrid composite. materials and methods: in this experimental study, 135 composite blocks (45 s...

statement of the problem addition of metallic nano-particles to composite resins can change their water contact angle purpose the aim of this study was to evaluate the effect of addition of nano-particles of silver and zinc oxide to composite resins on their water contact angle materials and methods this in vitro study was performed on 60 composite resin samples. nano-silver and nano-zinc oxide...