Small specimen test techniques for evaluation of tensile flow properties - Evolution and developmental activities at IGCAR, Kalpakkam

The small specimen test techniques have been a subject of active research for the past 30 years. The idea of using small or miniature specimens for mechanical testing had actually originated in nuclear industry caused by space limitations in nuclear reactors for irradiation material testing with the added advantage of reduced radiation dose from smaller volumes during post-irradiation examination. Considering the potential applications of this technology for material characterization, the programme was initiated at IGCAR with the ab initio development of non conventional test techniques based on the use of small disc specimens of 3-8 mm diameters and 0.3-1.0 mm thick. The techniques that have been extensively studied are shear punch, small punch and ball-indentation tests. This paper will present the evolution of the research and developmental activities on punch and indentation based test techniques at the authors' laboratory along with their salient results and highlight the outcome of few applications of small specimen tests employed for evaluating tensile flow properties.