Synthesis and characterization of mechanically alloyed and shock-consolidated nanocrystalline NiAl intermetallic

Effects of processing and powder size on microstructure and reactivity in arrested reactive milled Al+Ni

“…An investigation of the effects of ball-milling NiAl powder powders beyond SHS can be found in [21].…”

“…Four stainless steel vials were used at random to reduce the dependence of milling on any contaminants deposits or difference in roughness on the inside surfaces. It is shown in [34] that contamination is an order of magnitude less using stainless steel vials and grinding media and was reported at 0.35% Fe contamination for 8 hours of continuous milling [21]. Each ball-milling experiment is performed with a molar ratio of Ni 0.5 Al 0.5 with three different Ni powders (Ni: 5-15 mm, -300 mesh, -150+200, 99.8% pure, Alfa Aesar) and Al powders (Al: H2, H30, H50, 99.7% pure, Valimet, Inc.).…”

“…The refinement process consists of the cold welding of powder grains within the contact areas of impacting balls with one another or the balls with the walls of the vial [5,8,21]. Prior to reaction the particle microstructure may consist of many layers due to the flattening of the particles for materials with relatively high deformability.…”

New Entropic Routes for Nano‐Bands and Nano‐Particles

“…The problem is illustrated by an example from NiAl alloys. A summary of reported mechanical properties [31,40,41] and phase constituents of micropyretically synthesized NiAl alloy objects is shown in the previous study [9] and Table 1 [10,27,29,[42][43][44][45][46][47]. The increase in compressive ductility and increase in toughness are not fully correlated.…”

Underwater Explosive Shock Consolidation of Nanocomposite Pr<SUB>2</SUB>Fe<SUB>14</SUB>B/&alpha;-Fe Magnetic Powders

“…[8][9][10][11] The main attraction of this approach is that fully dense bulk compacts can be fabricated without introducing significant changes in microstructure. 12) Recently, shock consolidation of bulk nanocrystalline magnetic alloys, such as NdFeB, 13) SmCo, 14) and SmFeN magnets, 15) has been reported. Explosive compaction, with the shock wave transmitted into the powders through a water layer, provides the ability to employ a more dispersed shock wave of prolonged duration, which in some cases is beneficial for attaining better consolidation by providing an increased time for interparticle bonding.…”