The origin of the martensitic transition in the magnetic shape memory alloy Ni-Mn-Ga has been widely discussed. While several studies suggest it is electronically driven, the adaptive martensite model reproduced the peculiar nonharmonic lattice modulation. We used femtosecond spectroscopy to probe the temperature and doping dependence of collective modes, and scanning tunneling microscopy revea...

Austenite is a semi-stable phase in most stainless steels that deforms to martensite under Md30 and forms martensitetype ά and ε due to the deformation in the steels. Since the distribution of strain induced martensite plays animportant role in achieving desired properties, the main objective of the present work is to model martensitedistribution of ά during cold rolling using...

aisi 4340 steel is one of the super strong steels that can be selected for different applications. by designing theproper cycles of heat treatment, the optimum microstructure and properties of this steel can be achieved. in thisstudy, different heat treatment cycles were introduced to achieve the optimum microstructure and improve themechanical and magnetic properties of aisi 4340 steel. the re...

This work is to the best of my knowledge original, except where acknowledgements and references are made to previous work. Neither this, nor any substantially similar dissertation has been or is being submitted for any other degree, diploma or other qualification at any other university. This dissertation does not exceed 60,000 words in length. Abstract iii DFT Pak, Jun Hak 20080959 Coalesced s...

in this study, the effects of nitrogen addition on the production of ultrafine/nano grained aisi 201l stainlesssteel by advanced thermo-mechanical process were investigated. cast samples were first homogenized at 1200 °c for 4 h, hot-rolled at 1100 °c and finally, solution-annealed at 1150 °c for 2.5 h. unidirectional and cross multipass cold rolling at 25 °c was carried out to 90% reduction in...

It is well known that most important problems faced by many industrial machine parts are the wear and tear which increases the cost of production and wasted time for the replacement process. Now-a-days cryogenic treatment would be regarded as one of the most important processes in the field of industries, and it is the ultra modern type of processing to make the metals more resistant to wear an...

Maraging steels gain many of their beneficial properties from heat treatments which induce the precipitation of intermetallic compounds. We consider here a two-stage heat-treatment, first involving austenitisation, followed by quenching to produce martensite and then an ageing treatment at a lower temperature to precipitation harden the martensite of a maraging steel. It is shown that with a su...

In the present research, microstructure and mechanical properties of low-density Fe-0.72Mn-3.7Al-0.53C steel were investigated after solution treatment at 900 °C, 1000 1110 °C 1200 for 1 h. The density is about 7.0 g·cm−3 due to addition a higher content aluminum elements. was characterized by scanning electron microscopy (SEM) transmission (TEM), behavior analyzed room temperature tensile test...

A workshop has explored interactions of materials science, applied mechanics, physics and mathematics in understanding fundamentals of martensitic transformations. System theory offers a framework for addressing realistic complexity. Theory of invariant-plane kinematics has been extended to multivariant plate groups and hierarchical structures. Electronic total energy calculations explore the o...