Defence Metallurgical Research Laboratory

About: Defence Metallurgical Research Laboratory is a facility organization based out in Hyderabad, India. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 1208 authors who have published 2662 publications receiving 51663 citations.

Microstructure and Tensile Ductility in a β Heat Treated Titanium Alloy

Abstract: The nature of tensile failure in aβ-treated titanium alloy, Ti-6Al-l.6Zr-3.3Mo-0.3Si, is demonstrated to be strongly dependent on cooling rate followingβ treatment. A characterization of microstructure, the fracture surface of tensile tested samples, and the associated slip behavior shows the fracture mode to be determined by the microstructure as well as composition of the a laths. A martensitic matrix with fine grain boundary α particles leads to intergranular failure. At slower cooling rates, α laths form as side plates from grain boundary allotriomorphs, and an fcc interface phase is present at thea lath/retainedβ interfaces. This microstructure results in transgranular fracture caused by ductile failure at the α lath/β interfaces within the grains rather than at grain boundary ⇌. If the composition is equilibrated across the a laths by a long-term anneal followingβ treatment, the slip mode becomes extremely planar leading to slip band related cracking across the grains.

Effect of volume fraction of SiC p reinforcement on the processing maps for 2124 Al matrix composites

Abstract: The hot working characteristics of 2124 Al alloy matrix composites reinforced with 0, 5, 10, 15, and 20 vol pct of SiC particulate, produced by the powder metallurgy route, were studied using processing maps. The maps based on the dynamic materials model were generated from the flow stress data obtained from hot compression tests, carried out at strain rates ranging from 0.001 to 10 s−1 and temperatures ranging from 300°C to 525°C. All the compositions studied exhibited domains of dynamic recrystallization (DRX) and superplasticity. Flow instabilities were found at higher strain rates and lower temperatures. The composite with 10 vol pct SiC showed a tendency for abnormal grain growth at lower strains, which manifested itself as a shift in the DRX domain to lower strain rates and the disappearance of the superplasticity domain.