Brittle behavior of a dilute copper-beryllium alloy at 200 C in air. [Cu-0. 3Be-0. 5Co and Cu-0. 3Be-0. 5Co-0. 04Zr]

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90058-2· OSTI ID:6935075

Misra, R D.K.; McMahon, Jr, C J; Guha, A ^[1]; Guha, A ^[2]

---

1. Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Materials Science and Engineering
2. Brush Wellman Inc., Cleveland, OH (United States)

Intergranular cracking in a Cu-Be alloy tested in low-cycle fatigue at various partial pressures of oxygen was observed more than 20 years ago by Coffin. This phenomenon has also been observed in other copper alloys. Minute additions of zirconium were shown to improve the high temperature ductility of these alloys. This led to experiments to determine the effects of a zirconium addition to a cobalt-containing high strength, high conductivity Cu-Be alloy which showed intergranular cracking during hot-deformation processing. It is of interest to examine this phenomenon in the light of recent studies of dynamic embrittlement related to sulfur-induced intergranular cracking of low-alloy steels (stress-relief cracking) and to tin-induced intergranular cracking of Cu-Sn alloys. The dynamic embrittlement phenomenon involves the ingress of low-melting surface-adsorbed elements along grain boundaries under the influence of an applied tensile stress, in the manner of Coble creep. At any given temperature, the rate of ingress of low-melting surface-adsorbed elements along grain boundaries under the influence of an applied tensile stress, in the manner of Coble creep. At any given temperature, the rate of ingress, and thus the rate of cracking, varies with some power of the local stress. Because Cu-Be alloys can support very high stresses, one would anticipate that they could be susceptible to dynamic embrittlement in the presence of oxygen, a common embrittling element in metals. Accordingly, some preliminary experiments have been carried out on a dilute Cu-Be alloy with and without the presence of zirconium to see if its behavior is consistent with the dynamic embrittlement phenomenon.

• OSTI ID: 6935075
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 31:11; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
BERYLLIUM ADDITIONS
BERYLLIUM ALLOYS
COBALT ADDITIONS
COBALT ALLOYS
COPPER ALLOYS
COPPER BASE ALLOYS
CRACK PROPAGATION
DATA
ELEMENTS
EMBRITTLEMENT
EXPERIMENTAL DATA
INFORMATION
METALLURGICAL EFFECTS
METALS
NUMERICAL DATA
TRANSITION ELEMENTS
ZIRCONIUM
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS