Accession Number : ADA116663

Title :   Fatigue Behavior of Solution Treated and Quenched Ti-6Al-4V.

Descriptive Note : Final rept.,


Personal Author(s) : Kennedy,James R

Full Text :

Report Date : May 1981

Pagination or Media Count : 66

Abstract : The effect of solution treating and quenching on titanium alloy Ti-6Al-4V was studied as a means to improve its fatigue resistance. Four separate heats of Ti-6Al-4V rod and one heat of sheet material were solution treated at temperatures ranging from 825 to 1040 C, and then water quenched. Screening tests were performed on the rod materials by fatigue testing at one level of constant strain amplitude (approx. + or - 1%) to determine the relative fatigue resistance and the overall heat treat responsiveness of each heat. Subsequently, selection of one heat was made for more complete evaluation of low and high cycle fatigue behavior and tensile properties. A relative measure of fatigue crack initiation resistance for various solution treated and quenched conditions of the sheet material was determined by acoustic emission. The fatigue test results for these materials showed that solution treating at particular temperatures in the alpha - beta field follwed by quenching produced improvements in fatigue resistance compared to the annealed and solution treated plus aged conditions. Based on acoustic emission tests during fatigue cycling, solution treated and quenched material had improved resistance to early stage fatigue crack initiation. The optimum solution treated and quenched materials were characterized by low yield strength, low elastic moduli, high uniform and total strains, and high work hardening rates.

Descriptors :   *Titanium alloys , *Fatigue(Mechanics) , *Cracking(Fracturing) , Crack propagation , Aluminum alloys , Vanadium alloys , Rods , Sheets , Heat treatment , Processing , Solutions(Mixtures) , Quenching , Strain(Mechanics) , Yield strength , Tensile properties , Elastic properties , Test methods , Phase studies , Acoustic emissions , Metastable state , Tensile testers , Fatigue tests(Mechanics)

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE