the flow stress of steel depends significantly on microstructural changes taken place during hot deformation processes. in hot deformation processes, the flow stress of steel is influenced by two main metallurgical phenomena, i.e. recovery and recrystallization, along with its chemical composition and thermo-mechanical parameters. the final mechanical properties of steel are also determined by ...

Several investigators have pointed out that electron and neutron contamination from high-energy photon beams are clinically important. The aim of this study is to assess electron and neutron contamination production by various prostheses in a high-energy photon beam of a medical linac. A 15 MV Siemens PRIMUS linac was simulated by MCNPX Monte Carlo (MC) code and the results of percentage depth ...

in the present work, structural characteristics and tribological properties of the ti-al-cr-(si)-c-n nanocomposite films coated on the spk 1.2080 tool steel bypvd technique have been investigated. the pvd coating process was carried out using ti (si) al and cral cathodes at 150 a current, 40 v bias and (ar)0.1(ch4)0.45(n2)0.45 gas mixture for 50 min. evaluations were conducted by om, fesem, afm...

OBJECTIVE To compare the archwires inserted during the final stages of the orthodontic treatment with the generated moments at 0.018- and 0.022-inch brackets. MATERIALS AND METHODS The same bracket type, in terms of prescription, was evaluated in both slot dimensions. The brackets were bonded on two identical maxillary acrylic resin models, and each model was mounted on the orthodontic measur...

In this study, physical vapor deposition (PVD) Ti-Cr-N coatings were deposited at two different temperatures 100 and 400ºC on hardened and tempered tool steel substrates. The influence of the applied deposition temperature on the physical and mechanical properties of coatings such as roughness, thickness, phase composition, hardness and Young’s modulus were evaluated. Phase compositions were st...

Among the various methods existing to fabricate porous titanium for structural or biomedical applications, the spaceholder approach is particularly useful as it allows a close control of pore size, shape and fraction. In this method, a blend of pure or alloyed titanium powders and space-holder materials are cold-pressed into a preform which is sintered in vacuum. During the early stage of sinte...

Metal release from implantable metals and the properties of oxide films formed on alloy surfaces were analyzed, focusing on the highly biocompatible Ti-15Zr-4Nb-4Ta alloy. The thickness and electrical resistance (Rp) of the oxide film on such an alloy were compared with those of other implantable metals. The quantity of metal released during a 1-week immersion test was considerably smaller for ...

The nickel-titanium (Ni-Ti) alloys used in endodontics contain 56% Ni and 44% Ti. The 2 unique features related to clinical dentistry (i.e., shape memory effect and superelasticity) are due to the transition from austenite to martensite in Ni-Ti alloy. When a superelastic Ni-Ti alloy undergoes a low tensile loading, normal elastic behavior occurs. In fact, at higher tensile loads, the elastic s...