-----Original Message----- From: MarkI-ZeroPoint >> "We know that Ni powder sinters at the temperature being produced"
> What about adding some small amount of some other element to raise the sintering/melting temp; commonly done in alloying. Look no further than the hydride, but beware."Nickel hydride" has a number of specialized meanings in metallurgy - one of which is a true alloy made by combining nickel and a small amount of hydrogen under pressure. Once alloyed properly, the proton does not come out of this alloy before it is melted. If there is about one hydrogen atom absorbed for every fourteen nickel atoms, the properties are very different from common NiH (stoichiometric) or anything in between. Here is a picture of the FCC crystal, which represents possibly the best way that nickel reacts gainfully to produce a 300 eV photon. There are fourteen Ni atoms and the crystal will absorb only one proton. More hydrogen than one converts the structure to another phase. http://dic.academic.ru/pictures/wiki/files/50/200px-FCC_crystal_structure.sv g.png Nickel hydride with optimum hydrogen content is harder, stronger and more resistant to sintering at the expense of ductility. Normally, nickel is the face-centered cubic or FCC structure called alpha-nickel. As soon as anything more disruptive than a single proton alloys with it, it tends to go into the beta-phase, which has a different crystal structure. http://www.thenakedscientists.com/HTML/uploads/RTEmagicC_AnnealingPaperClips -BCC_02.png.png Hydrogen atoms bond strongly with any nickel surface (either alpha or beta) so for now, we are only talking about crystal properties and phases for fully alloyed hydrides. Bottom line: In this alternative interpretation of Millsean hydrogen deep redundancy (to below ground state) - it can happen several ways - one of which is when a proton is lodged in the center of a true alpha-nickel FCC crystal. That does not happen unless the nickel alloy is specially made with only a lesser amount of hydrogen being absorbed (few parts per thousand by mass). However, this can happen inadvertently if nickel is aged under pressure in hydrogen for an extended time period (weeks). If one is very lucky and gets it right... or else if one knows where to buy the right hydrided alloy - bingo. (perhaps it is made by a dwarf who lives in the cellar in an Italian castle :) Jones
