Accession Number : ADA259808


Title :   Microstructure and Texture Control of Fatigue in Hydrogen and Marine Environments


Descriptive Note : Fiscal year letter 1 Oct 1991-30 Sep 1992


Corporate Author : MINNESOTA UNIV MINNEAPOLIS DEPT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCE


Personal Author(s) : Gerberich, William W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259808.pdf


Report Date : 30 Sep 1992


Pagination or Media Count : 9


Abstract : It is currently not understood how the anisotropic elastic, plastic and fracture characteristics interact with environment to limit fatigue life in a corrosive medium. This program examines how texture and anisotropic slip character interact in two general classes of BCC iron base and HCP titanium bare alloy systems. Selected area electron channeling, transmission electron microscopy, atomic force microscopy, continuous microindentation and fracture micromechanic methods are being utilized to evaluate microstructural and surface layer effects on environmentally-induced fatigue initiation. In addition, as it is essential to understand the transition from small crack to long crack behavior, additional threshold studies on both Fe-Si and HSLA polycrystals need to be accomplished. In this way, the various stages of nucleation and growth may be combined together for life prediction. The objective is to provide a partial basis for alloy and materials processing design against fatigue in a marine environment.


Descriptors :   *FATIGUE(MECHANICS) , *IRON ALLOYS , *TITANIUM ALLOYS , FATIGUE LIFE , CRACKING(FRACTURING) , CYCLIC LOADS , DUCTILITY , HYDROGEN , BRITTLENESS


Subject Categories : Properties of Metals and Alloys


Distribution Statement : APPROVED FOR PUBLIC RELEASE