Solution softning and strengthening of iridium in arc-melted tungsten

Conference · Tue Jan 01 04:00:00 EST 1991 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:5690690

Luo, A; Shin, K S; Jacobson, D L ^[1]

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1. Department of Chemical, Bio and Materials Engineering, Arizona State University Tempe, AZ 85287-6006, USA (USA)

A comprehensive investigation has been performed on the hardness, tensile properties, microstructure, and fracture behavior of arc-melted W and W-Ir alloys at room temperature and from 1600 K to 2600 K. The objectives of the present study were to examine solution softening effect of Ir in W at room-temperature, and to characterize the strength properties of dilute W-Ir alloys as the functions of iridium content at high temperatures. Tensile tests were conducted in a vacuum better than 1.3{times}10{sup {minus}5} Pa (10{sup {minus}7} torr) with a strain rate of 10{sup {minus}3}/sec. It was found that iridium was more effective insoften and ductilize tungsten than rhenium at room temperature, and the minimum hardness and maximum elongation occurred at iridium content about 0.4 wt.%. In dilute W-Ir alloys, the high-temperature strength increment was proportional to the atomic content of iridium. And the addition of iridium in arc-melted tungsten substantially increased both the strain-hardening exponent and the activation energy of plastic deformation above 1600 K. Besides, transgranular fracture was found to be the dominant fracture mode for arc-melted W-Ir alloys, but the tendency of fracturing intergranularly became stronger with increasing iridium content and temperature.

• OSTI ID: 5690690
• Report Number(s): CONF-910116--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 217:1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ACTIVATION ENERGY
ALLOYS
CRYSTAL STRUCTURE
DEFORMATION
ELEMENTS
ENERGY
FRACTURE PROPERTIES
HARDENING
HARDNESS
IRIDIUM ALLOYS
MECHANICAL PROPERTIES
MEDIUM TEMPERATURE
METALS
MICROSTRUCTURE
PLATINUM METAL ALLOYS
STRAIN HARDENING
TENSILE PROPERTIES
TRANSITION ELEMENTS
TUNGSTEN
TUNGSTEN ALLOYS
VERY HIGH TEMPERATURE