Dynamic deformation behavior of an oxide-dispersed tungsten heavy alloy fabricated by mechanical alloying

Abstract

The objective of this study is to investigate the dynamic deformation and fracture behavior of an oxide-dispersed (OD) tungsten heavy alloy fabricated by mechanical alloying (MA). The tungsten alloy was processed by adding 0.1 wt pct Y 2 O 3 powders during MA, in order to form fine oxides at triple junctions of tungsten particles or at tungsten/matrix interfaces. Dynamic torsion tests were conducted for this alloy, and the test data were compared with those of a conventional liquid-phase sintered (LPS) specimen. A refinement in tungsten particle size could be obtained after MA and multistep heat treatment without an increase in the interfacial area fraction between tungsten particles. The dynamic test results indicated that interfacial debonding between tungsten particles occurred over broad deformed areas in this alloy, suggesting the possibility of adiabatic shear-band formation. Also, oxide dispersion was effective in promoting interfacial debonding, since the fine oxides acted as initiation sites for interfacial debonding. These findings suggest that the idea of forming fine oxides would be useful for improving self-sharpening and penetration performance in tungsten heavy alloys.

Effect of Yttrium Oxide Dispersion on the Microstructure and Properties of Tungsten Heavy Alloys

“…In the present study, grain size control can therefore be attributed to the presence of yttrium oxides in the W-M interface. Similar observations of grain size reduction wherein oxide dispersed alloy has an average tungsten grain size of 15 µ against 27 µ of a base alloy has been reported in 93W-4.9Ni-2.1Fe alloy with 0.1 wt % oxide content 11 . In the present study, as listed in Table 2, average grain size is 32±6µ after LPS and 16±7µ after second swaging.…”

Synthesis of nanocrystalline carbide in tungsten alloy by mechanical alloying and annealing

“…As demand for higher and better mechanical properties increases in recent years, amorphous and nanocrystalline tungsten alloys have attracted enormous research attention. It has been demonstrated that the mechanical properties of tungsten alloys can be modified and improved by controlling their microstructures through mechanical alloying (MA) [1][2][3][4][5][6][7][8][9][10], alloying with Mo and Re [11], cyclic heat treatment [12,13], surface carburization [14,15], solid-state sintering [16] and oxide dispersion [5,17,18].…”

SPS densification behavior of W-5.6Ni-1.4Fe heavy alloy powders

“…In order to prevent the grain growth, lots of research papers focused on adding inhibitors to hinder grain coarsening by changing the energy states of the W grains during sintering. Recent literature has reported that adding trace amount of rare earth elements or their oxides can refine the grain size and enhance the penetration performance of tungsten heavy alloy [12][13][14][15]. Some researchers adopt high-energy ball milling (HEBM) combining with novel sintering technologies, such as two-stage sintering, microwave sintering and electric current activated sintering, to prepare ultrafine grained WHAs or tungsten [2,[16][17][18][19].…”