background and aims. in order to fabricate prostheses with high accuracy and durability, soldering techniques have been introduced to clinical dentistry. however, these prostheses always fail at their solder joints. the purpose of this study was to evaluate the effect of gap distance on the tensile strength of base metal solder joints. materials and methods. based on ada/iso 9693 specifications...

This in vitro study evaluated the effect of tooth age on the tensile bond strength of Prime & Bond NT adhesive system to dentin. Human third molars from the five age groups were analyzed: A- 17 to 20yrs, B- 21 to 30yrs, C- 31 to 40yrs, D- 41 to 50yrs and E- 51 to 63yrs. The occlusal enamel was removed using a diamond saw under water cooling and the dentin surface was wet-ground with 600-grit Si...

The phenomenology of intergranular sulfur attack in nickel and nickel-base alloys and the resulting embrittlement on post-exposure tensile testing was investigated. Using Ni 270 as a model material, specimens were exposed at temperatures between 450°C and 800°C to Fgous sulfur e vironments with sulfur partial pressures ranging from atm. to 10' B atm. Increasing exposure temperature and increasi...

Aiming at the mechanical testing of three-dimensional specimens with feature size of centimeter level, a miniaturized tensile platform, which presents compatibility with scanning electron microscope (SEM) and metallographic microscope, was designed and built. The platform could accurately evaluate the parameters such as elastic modulus, elongation and yield limit, etc. The calibration experimen...

This study evaluated the effect of heat treatment on CrNi stainless steel orthodontic archwires. Half of forty archwires of each thickness - 0.014" (0.35 mm), 0.016" (0.40 mm), 0.018" (0.45 mm) and 0.020" (0.50 mm) (totalling 160 archwires) - were subjected to heat treatment while the remainder were not. All of the archwires had their individual thickness measured in the anterior and posterior ...

Tensile armour wires provide a resistance to longitudinal stresses. Flexible pipe manufacturers need to know the effect of defects such as scratches and cracks, with dimensions less than 0.2mm which is the limit of the current nondestructive detection technology, on the fracture stress and fracture strain of the wire for quality assurance purposes. Recent research involving the determination of...

High-temperature properties of the continually cast low carbon steel slabs are tested on various equipments [1 7]. The high temperature tensile strength test is the most used one and the primary evaluated quantity, plasticity, is mostly assessed by reduction of area values. Several heating techniques are used for high temperature tensile strength tests and the testing is performed at various de...

In this paper, a new method is proposed for the production of MWCNTs/PVC (multi-walled carbon nanotubes/ polyvinyl chloride) nanocomposites. In this method, a spray is used to produce layers of carbon nanotubes within a PVC matrix. Various parameters influence the production of the nanocomposite and its mechanical properties. These parameters are studied separately and the effect of each of par...

OBJECTIVE The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. MATERIAL AND METHODS Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPD...

The more common use of instrumentation in impact testing opened up the possibility to apply fracture mechanics testing methods to polymers at moderately high impact rates. Tensile impact testing offers some advantages over the more common three-point bending and compact tension geometries. Most importantly the dynamic effects encountered at (moderately) high impact rates are less significant du...