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...

Au-Sn solid–liquid interdiffusion (SLID) bonding is a novel and promising interconnect technology for high-temperature applications. This article gives a review over previously published work on Au-Sn SLID bonding. An overview of the crystal phases and the thermomechanical properties of the Au-Sn phases relevant for Au-Sn SLID bonding is given. A summary of the bonding conditions used during Au...

The classical Einstein’s relation for the Brownian migration has a mesoscopic character and it deteriorates when e.g. diffusion in solids is considered in the nanoscale (i.e. if the diffusion distance is comparable with the atomic spacing). This behaviour is strongly related to the well-known diffusion paradox, predicting infinitely fast diffusion kinetics at short times (distances). Indeed, ac...

Short cracks, extending to the interdiffusion zone, have been observed in platinum-modified nickel-aluminide diffusion coatings on single-crystal CMSX-4 superalloys after these have been subject to short (10 min) rapid thermal cycles. The cracks were revealed after removing the thermally grown oxide formed during cycling on the coating surfaces. Cracking was observed for coatings subject to the...

The early-stage kinetics of interdiffusion in compositionally modulated films have been studied by Monte-Carlo simulations on an Ising lattice in two and three dimensions, using nearest-neighbor interactions. For a negative heat of mixing and below the order-disorder transition temperature, if a short-wavelength modulation is along a direction that is not consistent with long-range order, then ...

The effects of Zn doping in the substrate on the thermal stability of GaAsyAl Ga As single quantum well are investigated 0.24 0.76 by 900 8C rapid thermal annealing and low-temperature (12 K) photoluminescence measurements. An improvement in thermal stability is demonstrated for structures grown on Zn-doped GaAs in comparison with those grown on semi-insulating and Sidoped GaAs substrates. It i...