Creep rupture properties of Ti-8Al-1Mo-1V alloy

Abstract

Creep tests were made at 600, BOO, lOOO , and 1200 O F (5BB, 699, Bll, and 921 O K) on duplex-annealed Ti-BAl-lMo-l V alloy specim ens. Creep-test co ndition s we re selected to produce creep rates ranging from 0.1 10 50,000 pe rce nt per 1,000 hours and rupture times ranging from 0.1 to about 10,000 hours. Conformance of th e tes t data to creep theories was obtained over a limited range of stress, strain, creep rate and temperature_ C reep behavior was influ enced by microstru ctural c han ges durin g creep and by prior thermal-mec hanical treatment. Engineering-design curves are included in thi s pape r.

The tensile and tensile-creep deformation behavior of Ti–8Al–1Mo–1V(wt%)

“…A stress level of 315 MPa represents 0.6 of the yield strength at 455 o C [17]. Similar to the lower temperature/higher stress creep test, less grains displayed slip traces at this creep condition compared to the tensile tested sample deformed to a similar strain level.…”

“…Because the local stress tensor is not known in a particular location, all of the Schmid factor values were calculated based on a uniaxial global stress state. [11][12][13][14][15][16][17][18][19][20]) was determined to be the active slip system with a Schmid factor of 0.49. It is noted that the basal slip systems numbered 1 and 2 were also considered however their Schmid factors were 0.26 and 0.24, respectively.…”

Effect of notch geometry and temperature on the creep-rupture behavior of a titanium alloy

“…"parameter" relations for each group of notched specimens; however, no sim ple translation was available to cause all the curves to coi ncide. The difference in the shape of these curves from those previously shown [6] is due to the fact th a t the stress values in fi gure 8 are plotted on a lo g instead of a lin ea r basis. Thi s method of analysis is recommended for compa rin g and storin g engi.…”

“…It was previously shown that creep data for the unnotched specimens of this Ti-8AI-IMo-1 V alloy [6] could be described by a sin gle curve. The time·tempera ture paramo eter used was derived by Larson and Mill er [8 ].…”

“…This alloy was selected for th e research as it is one of the candida te materials for aerospace applications in components used at intermedi ate tempera tures (up to 1000 OF ) . Furthermore, its shorttime tensile notch behavior a nd lon g-time creep properti es on unnotched cylindri cal specimens have been ex tensively investigated at the National Bureau of Standards [3,6] .…”