Abstract
The results of studies of W-Ni-Co-Fe experimental alloy, with chemical
composition assuring a possibility of producing Ni-based
supersaturated solid solution are presented. The alloy was prepared from
tungsten, nickel, cobalt and iron powders which were first mixed then
melted in a ceramic crucible where they slowly solidified in hydrogen
atmosphere. Next specimens were cut from the casting and heated at a
temperature 950o C. After solution treatment the specimens were water
quenched and then aged for 20 h at a temperature 300o C. The specimens
were subjected to microhardness measurements and structure investigations.
The latter included both conventional metallography and SEM observations.
Moreover, for some specimens X-ray diffractometry studies and TEM
investigations were conducted. It was concluded that quenching lead to an
increase of tungsten concentration in nickel matrix which was confirmed by
Ni lattice parameter increase. Aging of supersaturated solid solution
caused strengthening of the Ni-based matrix, which was proved by hardness
measurements. The TEM observation did not yield explicit proofs that the
precipitation process could be responsible for strengthening of the alloy.
Go to article