Microstructure and Texture Evolution During Sub-Transus Thermo-Mechanical Processing of Ti-6Al-4V-0.1B Alloy: Part II. S
- PDF / 2,697,401 Bytes
- 15 Pages / 593.972 x 792 pts Page_size
- 51 Downloads / 201 Views
TION
IN the first part of this study, microstructure and texture development for Ti-6Al-4V-0.1B alloy have been presented in comparison with a control Ti-6Al-4V alloy.[1] The second part addresses the static annealing response of Ti-6Al-4V-0.1B alloy vis-a`-vis the control Ti-6Al-4V alloy. Among the various rolled materials, the low temperature deformed specimens of the two alloys have been preferred for the present study in order to distinguish the effect of static annealing from the dynamic globularization during high temperature rolling. In the processing of titanium and its alloys, the conversion from lamellar to equiaxed morphology is of great importance since superior strength and ductility are well balanced for an equiaxed microstructure. Such microstructural engineering is generally accomplished by sub b-transus deformation followed by post-deformation sub-transus annealing.[2–4] While the static annealing behavior of the deformed Ti-6Al-4V alloy is well documented and micromechanisms for microstructural conversion are well understood,[5–9] no such study has been reported for the boronmodified Ti-6Al-4V alloy. A comprehensive understandSHIBAYAN ROY, formerly Ph.D. Student with the Department of Materials Engineering, Indian Institute of Science, Bangalore, India, is now Post-doctoral Researcher with the Institut fu¨r Werkstoffwissenschaft und Werkstofftechnik, Chemnitz University of Technology, Chemnitz, Germany. S. KARANTH, Summer Trainee, and SATYAM SUWAS, Associate Professor, are with the Department of Materials Engineering, Indian Institute of Science, Bangalore, India. Contact e-mail: [email protected] Manuscript submitted May 31, 2012. Article published online March 20, 2013 3322—VOLUME 44A, JULY 2013
ing of microstructure and texture evolution is, therefore, lacking for this alloy system. In the present work, a systematic study has been carried out pertaining to the evolution of microstructure and texture after annealing of the warm-rolled [973 K (700 C) up to 90 pct thickness reduction] Ti-6Al-4V-0.1B alloy. A similar experiment has been performed on the Ti-6Al-4V control alloy. The effect of boron is finally separated from the similarities and differences in the microstructure and texture of the two alloys in self-same conditions. II.
EXPERIMENTAL PROCEDURE
A. Material The details of the starting alloy compositions and cast ingot specifications are provided in Section II–A of Part I. For this part of the investigation, the warm-rolled specimens of Ti-6Al-4V and Ti-6Al-4V-0.1B (hereafter referred to as Ti64 and Ti64+B, respectively), namely the ones rolled at 973 K (700 C) up to a thickness reduction of 90 pct, were chosen for the subsequent annealing experiments. B. Annealing Experiment The annealing experiment involve heat treatment of smaller coupons (20 mm 9 5 mm 9 1 mm) prepared from the sub-transus rolled strips of the two alloys. The specimens were isothermally annealed at 1173 K (900 C) for 15, 30, 45, 60, 75, and 90 minutes in the case of Ti64 and 15, 30, 45, and 60 minutes fo
Data Loading...
