Effect of substructure on intergranular cavitation at high temperature

• Published in: Scripta metallurgica et materialia Vol. 31; no. 6; pp. 723 - 728
• Main Authors: Lim, L.C., Lu, H.H.
• Format: Journal Article
• Language: English
• Published: Seoul Elsevier B.V 15.09.1994; Oxford Pergamon Press; New York, NY
• Subjects: 360102 - Metals & Alloys- Structure & Phase Studies; 360103 - Metals & Alloys- Mechanical Properties; ALLOYS; ALUMINIUM ALLOYS; ALUMINIUM BASE ALLOYS; Applied sciences; COPPER; ELEMENTS; Exact sciences and technology; FRACTURE PROPERTIES; Fractures; MAGNESIUM ALLOYS; MATERIALS SCIENCE; MECHANICAL PROPERTIES; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; METALS; Metals. Metallurgy; MICROSTRUCTURE; TEMPERATURE DEPENDENCE; TRANSITION ELEMENTS; Aluminium base alloys; Creep; Ductility; Stress strain relation; Rupture; Mechanical properties; Substructure; Experimental study; Grain boundary; Magnesium alloy; Fracture surface; Void; Microstructure; Binary alloy
• ISSN: 0956-716X
• DOI: 10.1016/0956-716X(94)90217-8

Though it is well recognized that intergranular cavitation at high stress locations on grain boundaries during creep is the cause for poor creep ductility the mechanism for the formation of the high stress locations is not understood. Two high purity coppers (99.9 and 99.99%) and Al-5Mg cylindrical creep specimens were tests to aid in developing a better understanding of this phenomenon. The copper specimens were tested in argon at 773K at either constant load or a strain rate of 8.3x10 exp -5 s exp -1 and the Al-5Mg samples were tested in air at constant stresses in the range 100 to 230 MPa at 523K. The data showed that microstructural features of 10 mu m or less can exert a large effect on the cavitation behavior. Also, the intersections of subgrain and grain boundaries are sites for cavity formation.