INVESTIGATIONS OF STRUCTURE AND MECHANICAL PROPERTIES OF NANO AND SUPERDISPERSED MECHANICALLY ACTIVATED TUNGSTEN PSEUDOALLOYS |
| 2 | |
| 2010 |
| scientific article | 539.4; 669.3 | ||
| 47-59 | tungsten pseudoalloys, mechanical activation, nano and superdispersed powders, sintering, spark plasma sintering, optimum sintering temperature, density, recrystallization, diffusion, mechanical properties |
| Sintering mechanisms, structure and mechanical properties of nano and superdispersed tungsten pseudoalloys
W-Ni-Fe (WNF) and W-Ni-Fe-Co (WNFC) have been investigated. The influence of tungsten particle size on the
optimum sintering temperature has been studied. The particle size has been changed by mechanical activation of the
original coarse-grained blend and by adding superdispersed particles obtained by sol-gel method and plasmochemical
synthesis. Free sintering and spark plasma sintering of nano and superdispersed powders have been used. The
dependence of pseudoalloy density on heating temperature has been found to be nonmonotonic with the maximum
corresponding to the optimum sintering temperature. It has been shown that an increase in mechanical activation
time and the strain rate, accompanied by pseudoalloy particle reduction and formation of nonequilibrium solid solutions,
leads to the reduction of the optimum sintering temperature. It has also been shown that using planetary highenergy
milling methods and high-rate spark plasma sintering it is possible to create superstrong tungsten alloys
whose mechanical properties (macroelastic stress, yield stress) exceed substantially similar properties of commercial
alloys. |
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