OBJECTIVE To compare the influence of archwire material (NiTi, beta-Ti and stainless steel) and brackets design (self-ligating and conventional) on the frictional force resistance. MATERIAL AND METHODS Two types of brackets (self-ligating brackets - Smartclip, 3M/Unitek - and conventional brackets - Gemini, 3M/Unitek) with three (0, 5, and 10 degrees) slot angulation attached with elastomeric...

Metal-on-ultra-high molecular weight polyethylene (UHMWPE) total hip replacements have been the most popular and clinically successful implants to date. However, it is well documented that the wear debris from these prostheses contributes to osteolysis and ultimate failure of the prosthesis, hence alternative materials have been sought. A range of 28 mm diameter bearings were investigated using...

In this paper, a software solution is presented for advanced friction modeling in metal forming processes, using a physically-based friction model. As input, the model requires the properties of the metal-lubricant combination used and the surface characteristics of the tooling and sheet material. As output, the friction coefficient is provided in both the boundary and mixed lubrication regime....

Tactile friction which occurs between the surfaces of hand-operated products and the user as well as the user’s perception of surface characteristics are both very important considerations for the function of engineering products. While the use of surface texture is known to greatly influence these properties, the effect of the governing textural parameters on the friction mechanisms between a ...

The process of size segregation in a model system of granular matter, consisting of 1600 spherical poly-disperse particles stirred by a rectangular bar moving periodically in the horizontal direction, was modelled by the discrete element method under different values of dynamic friction coefficient of the particle material. It has been shown that the dynamic friction coefficient influences the ...

Equal channel angular pressing is the most promising method of severe plastic deformation with the capability of producing ultrafine grained materials. These materials exhibit improved mechanical and physical properties compared with their coarse grained counter parts.The temperature variation in the sample during ECA-pressing is a key factor determining the final microstructure and mechanical ...

Friction stir processing (FSP) has been developed on the principles of friction stir welding (FSW) as an effective and efficien new method for grain refinement and microstructural modification, providing intense plastic deformation as well as higher strain rates than other conventional severe plastic deformation methods. FSP produces an equiaxed homogeneous microstructure consisting of fine gra...

The expulsion of material from either of two strong surfaces in relative movement is termed as wear. Wear can also be defined as surface damage, because of material relocation with no net change in weight or volume. It happens as a natural result and for the most part through surface interactions at severities. It is a system response and is not a material property. Interface wear is firmly com...

Finite element analysis based techniques are available to simulate cutting processes and offer several advantages including prediction of tool forces, distribution of stresses and temperatures, estimation of tool wear and residual stresses on machined surfaces, optimization of cutting tool geometry and cutting conditions. However, work material flow stress and friction characteristics at cuttin...