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LIFE ENHANCEMENT THROUGH SURFACE ENGINEERING OF TI-6AL-4V UNDER FRETTING FATIGUE CONDITION
Investigators
: Dr. S. Ganesh Sundara Raman and Prof. S. D. Pathak Sponsoring
agency :
MHRD Value :
Rs. 10 lakhs Period
: 2003 - 2006 Objectives: (i) To create a dedicated fretting fatigue test facility (ii)To study the
mechanisms of life improvement through surface modification of
Ti-6Al-4V under fretting fatigue loading
conditions.
EFFECT OF PULSED CURRENT AND ARC
OSCILLATION WELDING TECHNIQUES ON THE FATIGUE BEHAVIOR OF TI-6AL-4V
AND INCONEL 718 WELDS
Investigators
: Dr. S. Ganesh Sundara Raman and Prof. S. D.
Pathak Sponsoring agency :
DRDO Value
: Rs. 19.96 lakhs Period
: 2003 - 2006 Objectives: (i)
To
study the effects of
welding techniques like pulsed current and arc oscillation
(separately and in combination) on the welds of two materials - Ti-6Al-4V and Inconel 718
with respect to (a) high cycle fatigue
life (b) low cycle fatigue life
and (c) fatigue crack growth characteristics in the short and long crack regimes at low and high stress ratios
(ii) To compare the fatigue behavior of welds produced by the techniques of pulsed current and arc oscillation with that of welds made by continuous current welding without pulsing and arc oscillation
(iii) To compare the fatigue behavior of welds with that of base metal
(iv) To correlate the microstructure of the material with the fatigue behavior.
FRETTING FATIGUE
BEHAVIOR OF A STRUCTURAL
STEEL
Investigators : Dr. S. Ganesh Sundara Raman Sponsoring
agency :
DST Value :
Rs. 7.68 lakhs
Period : 2002 - 2005 Objectives: (1)To design and
fabricate an experimental set-up to do fretting fatigue tests on the
existing servo-hydraulic testing machine at the Materials Testing
Lab., Department of Metallurgical Engineering, IIT Madras. This will
help to initiate research work in the area of fretting fatigue at
IIT Madras. (2)To design, fabricate
and load-calibrate a Proving Ring to apply fretting on the test
specimens through bridge type contact
pads. (3)To get a good
understanding of fretting fatigue analyzed from two different
perspectives at the same time: Materials Science and Mechanical
Engineering. (4)To find out the effect
of fretting on the fatigue life of a structural steel by conducting
fatigue tests with and without
fretting. (5)To find out the effect
of contact pressure on the fretting fatigue life.
(6)To evaluate the
influence of pad span on the fretting fatigue
life. (7)To study the effect of
grain size on the fretting fatigue
behaviour. (8)To conduct two-stage
tests, i.e., fatigue tests with fretting for a fixed fraction of
life and subsequently plain fatigue tests (without fretting) in
order to study the effect of
fretting. (9)To describe fretting
damage qualitatively and evaluate failure mechanisms through
microstructural study employing optical and scanning electron
microscopy. (10) To predict fretting fatigue
strength/life using already available model(s) and compare with the
experimental results. PRE- AND POST-DEFORMATION STUDIES ON
SUPERPLASTICALLY FORMED TI-6AL-4V |
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Investigators
: Dr. S. S. Bhattacharya and Dr. S. Ganesh Sundara Raman
Sponsoring
agency : ISRO Value
: Rs. 7.16 lakhs Period
: 2001 - 2003 Objectives: a) To characterize superplastic Ti-6Al-4V in the temperature range of 850-950oC and in the strain rate range of 10-3s-1 to 10-4s-1. b) To estimate the ambient temperature tensile properties of the material before and after superplastic deformation. c) To perform a qualitative metallographic analysis of the material under different test conditions. d)
To
analyze the mechanical response of the material under the test
conditions with a view to understand the operating
mechanisms. e)
To
try and predict the change in the mechanical properties, as a rough
estimate, in terms of the constitutive equation of
flow.
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