A WEBINAR ON "DISTORTION ENGINEERING -ROLE OF RESIDUAL STRESSES"
By:
Prof. Dr. rer. nat. Ravi Kumar N V
Head, Central XRD Laboratory
Head, Dept. of Metallurgical and Materials Engg.
Indian Institute of Technology-Madras
Chennai 600036
at 6.30 PM on Saturday, 15th October 2022Pro.
About the talk:
Residual stresses arise in almost every stage of processing and machining of
materials/components and distortion is a manifestation of accumulation and relief of
residual stresses. All mechanical operations in the industry such as machining, rolling,
forming, assembly or thermal/thermomechanical operations that include, casting,
welding, phase transformations and chemical operations such as plating, carburizing
and nitriding can induce residual stresses. Accurate measurement of residual
stresses, therefore, becomes an important exercise that aids in life assessment and
design components for enhanced life. While mechanical methods (destructive
techniques) of measuring residual stresses may appear easier, they come with
various limitations although still in vogue in some industries.
Diffraction methods are now a standard practice world-wide for the measurement
of residual stresses since they are non-destructive and it is possible to estimate the
stresses for various complex shaped geometries and at different length scales to a
reasonable accuracy. X-ray diffraction in particular serves to be a very useful and a
quick way of measuring surface/sub-surface residual stresses using multiple
exposure sin2 technique. The technique has matured to be an industrial tool for
measuring residual stresses in components and the instrumentation permits
measurements without having to follow the Bragg Brentano geometry. However, what
makes this technique interesting and challenging is that, the effective use of this
technique requires knowledge of physics of X-ray diffraction, basic understanding
of metallurgy and mechanics.
The talk will begin with highlighting the importance of residual stress measurements
for industrial components followed by discussion on the basics of the measurement
technique. The talk will subsequently focus on realising the importance of selection
of the diffraction peak, methods of peak location and the statistical errors
associated with the maximum 2 value obtained from these methods. The talk will
end with a brief discussion on minimizing such statistical errors that aids accurate
measurements of residual stresses.
Prof. Dr. rer. nat. Ravi Kumar N V
Head, Central XRD Laboratory
Head, Dept. of Metallurgical and Materials Engg.
Indian Institute of Technology-Madras
Chennai 600036
at 6.30 PM on Saturday, 15th October 2022
Web Conference Link : https:// meet.google.com/kfd-jquk-esy
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Shubrajit Bhaumik
ASSOCIATE PROFESSOR
AMRITA VISHWA VIDHYAPEETHAM
CHENNAI
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