Effects of Grain Boundary Disorder on Yield Strength

It was recently reported that segregation of Zr to grain boundaries (GB) in nanocrystalline Cu can lead to the formation of disordered intergranular films [1,2]. In this study we employ atomistic computer simulations to study how the formation of these films affects the dislocation nucleation from the GBs. We found that full disorder of the grain boundary structure leads to the suppression of dislocation emission and significant increase of the yield stress. Depending on the solute concentration and heat-treatment, however, a partial disorder may also occur and this aids dislocation nucleation rather than suppressing it, resulting in elimination of the strengthening effect

Posterminaries: No, No, Nano

Your siblings already know that you do stuff that they cannot, and probably don’t even want to, understand. But their husbands and wives are more insistent. “What’s all this nanotechnology stuff, anyway? Where can I buy some stock in it?” There are colleagues, too, who still ask after all this time, “Is this ‘nano’ thing real or just a bunch of hype? Isn’t it just the same stuff we were already doing with a new label?

Posterminaries: Preferred Futures—and How Do We Get There From Here?

The last several months have seen new attention being paid to alternative sources of energy, and to the area of energy efficiency in general. You can choose your own reason for taking an interest: reversing global warming, peak oil theory, escaping from OPEC’s control of prices, stopping the flow of oil revenues to terrorist organizations, creating new jobs, or more parochially just generating more funding for research. These are all good reasons, and while some of them appeal to certain people more than others, there are now few people living in developed countries who deny the need to move away from dependence on oil, if not all fossil fuels