Accession Number : AD0674255

Title :   EFFECTS OF ENVIRONMENT ON THE FRACTURE BEHAVIOR OF TITANIUM AND ITS ALLOYS.

Descriptive Note : Final rept.,

Corporate Author : MARTIN MARIETTA CORP BALTIMORE MD RESEARCH INST FOR ADVANCED STUDIES

Personal Author(s) : Sedriks,A. J. ; Pugh,E. N.

Report Date : AUG 1968

Pagination or Media Count : 28

Abstract : A study was made of the mechanisms of stress-corrosion cracking (SCC) of titanium and Ti-Al alloys in methanol-iodine solutions. The path of cracking was found to depend on the composition of the alloy. In pure titanium and a Ti-2.09 w/o Al alloy SCC is intergranular. In higher alloys (> 5 w/o Al) only the initial part of the crack is intergranular, the later formed transgranular propagation stage exhibiting cleavage markings. Comparative studies of corrosion behavior, characteristics of SCC, and metallurgical factors (i.e. alloy composition and deformation characteristics) indicated that two mechanisms may be operative. The intergranular SCC process appears to involve stress-accelerated corrosion, while the transgranular process exhibits the characteristics of cleavage and appears to be related to a reduced propensity for cross-slip. Comparison of the SCC behavior in methanol-iodine solutions with that in a methanol-hydrochloric acid solution indicates that similar processes are operative in the latter solution. (Author)

Descriptors :   (*TITANIUM, STRESS CORROSION), (*TITANIUM ALLOYS, STRESS CORROSION), (*TITANIUM ALLOYS, FRACTURE(MECHANICS)), ANALYSIS, ALUMINUM ALLOYS, TIN ALLOYS, CARBINOLS, IODINE, SOLUTIONS(MIXTURES), CRACKS, ELECTROCHEMISTRY, HYDROCHLORIC ACID, METALLOGRAPHY

Subject Categories : Physical Chemistry
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE