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.

Effect of carbon addition on structure and mechanical properties of electroslag remelted Fe-20 wt.% Al alloy

Abstract: A high carbon Fe–20 wt.% Al–1.1 wt.% C alloy based on Fe3Al was melted under a flux cover by air induction melting (AIM). The AIM ingots were sound and free from gas porosity. Electroslag remelting of AIM ingots leads to alloys with good machinability and an attractive combination of mechanical properties. This is in contrast to the poor machinability and inferior strength reported for alloys with low ( 14 wt.% are susceptible to environmental embrittlement. The addition of carbon to these alloys may improve resistance to this embrittlement. It also leads to a significant increase in strength. Carbon addition has been shown to be beneficial for Fe–Al alloys containing up to 20 wt.% aluminium. It is argued that carbon is not an attractive alloying addition to alloys containing >22 wt.% (36.5 at.%) Al as it is likely to precipitate out as a soft graphite phase.

Effect of phase transformations during aging on tensile strength and ductility of metastable beta titanium alloy Ti–35Nb–7Zr–5Ta-0.35O for orthopedic applications

Abstract: Present work describes the aging response of biocompatible metastable beta titanium alloy Ti–35Nb–7Zr–5Ta (TNZT alloy for short) solution treated (ST) in (α + β) phase field. The primary focus of this study is to gain insight into the correlation among phase transformations, microstructure and mechanical properties of TNZT alloy pertinent for orthopedic applications. Complete recrystallization is observed during heat treatment at 750° C-8 h and these ST samples were subsequently aged from 300 °C to 550 °C for times up to 64 h. Very low elastic moduli in the range of 41–46 GPa are observed which is explained in terms of calculated values of alloying parameters bond order, d orbital energy value and electron per atom ratio. Lower aging temperatures have improved ductility (greater than 13% elongation), whereas higher temperature aged samples are failed in brittle manner (elongation

Effect of thermo-mechanical treatment on tensile properties of reduced activation ferritic-martensitic steel

Abstract: Effect of thermo-mechanical processing on tensile behaviour of reduced activation ferritic martensitic (RAFM) steel has been assessed and compared with those of the normalized and tempered steel. The thermo-mechanical treatment (TMT) was carried out by performing hot rolling and ageing in the austenite phase field, air cooled followed by tempering. TMT of the steel increased its hardness compared to the normalized and tempered condition. Tensile strength of the steel increased on TMT over the investigated temperature range of 300–923 K and more importantly was accompanied with increase in ductility. The strength increase on TMT was accomplished with the refinement of microstructure of the steel having finer martensite lath size and intra-granular precipitates. The tensile flow behaviour of steel has been assessed in the frame work of Voce's constitutive equation. The strength related parameters of the constitutive equation i.e. initial stress and saturation stress increased on TMT, while the recovery related parameter (nv) decreased marginally. The enhancement of tensile strength and ductility of the steel on TMT is considered due to microstructural refinement and its enhanced stability as reflected in appreciable lower relaxation and creep rates and the delayed in onset of tertiary stage of creep deformation.