Accession Number : ADA112805

Title :   Influence of Rare-Earth Additions on Properties of Titanium Alloys - Effects of Yttrium and Erbium Additions on Ti-8Al and Ti-10Al Alloy.

Descriptive Note : Technical rept. 1 Apr 79-31 Aug 80,

Corporate Author : MCDONNELL AIRCRAFT CO ST LOUIS MO

Personal Author(s) : Sastry,S M L ; Lederich,R J ; Pao,P S ; O'Neal,J E

PDF Url : ADA112805

Report Date : 31 Aug 1980

Pagination or Media Count : 62

Abstract : The influence of additions of 0.05-1.0 wt% Y and 0.2-2.0 wt% Er on the microstructure, slip distribution, fracture modes, and room- and elevated-temperature mechanical properties of Ti-8Al and Ti-10Al alloys was studied. Additions of up to 0.1 wt% Y and 0.2 wt% Er result in 50-200 nm incoherent dispersoids which effect grain refinement, reduce the planarity of slip, and significantly increase the ductility of Ti-8Al alloys. The additions further improve the room-temperature fracture toughness and room- and elevated-temperature low-cycle fatigue life of Ti-8Al and do not significantly alter the creep of Ti-8Al and Ti-10Al alloys. Higher amounts of Y and Er additions produce large, 1-5 micron dispersoids and produce no significant grain refinement or improvements in strength and ductility of the alloys.

Descriptors :   *TITANIUM ALLOYS, *RARE EARTH ELEMENTS, *ADDITIVES, *YTTRIUM, *ERBIUM, *MICROSTRUCTURE, *TENSILE PROPERTIES, FRACTURE(MECHANICS), MECHANICAL PROPERTIES, PLASTIC DEFORMATION, FATIGUE LIFE, YIELD STRENGTH, ROOM TEMPERATURE, PHASE STUDIES, CREEP STRENGTH, DISPERSIONS

Subject Categories : Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE