Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at hig...

In this research, variant selection of martensite transformed from ultrafine-grained (UFG) austenite fabricated by accumulative roll bonding (ARB) process and subsequent annealing was investigated with respect tomorphology of parentaustenitic phase. The results show that the original shape of austenite grain is very effective factor in determiningthe preferred variants of martensite transformed...

A solid-phase diffusion welding of coarse-grained and ultrafine-grained (UFG) specimens titanium near-α alloy Ti-5Al-2V used in nuclear power engineering was made by Spark Plasma Sintering. The failure the welded conditions hot salt corrosion electrochemical shown to have a preferentially intercrystalline character. In case presence macrodefects, crevice joints observed. resistance alloys again...

1 List of symbols and abbreviations 3 Chapter 1: INTRODUCTION 6 Chapter 2: LITERATURE SURVEY 8 2.1: The essence of ultra fine grained materials 8 2.2: Severe plastic deformation: a method for producing UFG microstructure 11 2.3: Physical properties of materials derived from GB character 15 2.4: Non-equilibrium GBs: theoretical aspects 16 2.4.1: Conventional models for GB structure 16 2.4.2: Mod...

Tensile tests were performed in situ on an ultrafine-grained (UFG) Al-Mg alloy using a micro-tensile module in a scanning electron microscope (SEM). The micro-strain evolution was tracked and measured using digital image correlation (DIC). A fine random speckle pattern was required to achieve high resolution and accuracy of strain measurement using DIC. To produce the speckle pattern, a pattern...

An ultrafine grained dual phase (UFG DP) steel containing niobium was produced by a new route utilizing simple cold-rolling and subsequent intercritical annealing of ferrite/martensite duplex starting structures. The effects of intercritical holding time on the microstructural evolutions and mechanical properties were studied. The results showed that increasing intercritical holding time enhnac...

Bauschinger test in uniaxial tension-compression mode was carried out for the first time on pure Al specimens having homogeneous ultra-fine grained (UFG) microstructures fabricated by equal-channel angular pressing (ECAP) and subsequent annealing processes. Significant stress (transient softening), energy parameter their strong dependences tensile plastic pre-strain at very early stage of defor...

The influence of Mo alloying on the thermal stability of grain size, dislocation density and hardness of ultrafine-grained (UFG) Ni alloys was studied. The UFG microstructure in alloys with low (∼0.3 at.%) and high (∼5 at.%) Mo contents was achieved by high-pressure torsion (HPT) performed for 20 turns at room temperature. The thermal stability of the two alloys was studied by calorimetry. A Cu...

Two different aspects of the thermal stability of grains were studied – (i) thermal stability of grain structure evolution during friction stir processing (FSP), and (ii) thermal stability of grains after FSP. It was concluded that Al3(Sc,Zr) dispersoids are effective in limiting grain growth to ultrafine grained regime (UFG) by stabilizing the microstructure during FSP. The presence of these d...

in the present study, the effect of grain size on the austenite stability was studied by nanoindentationtests in a 304l stainless steel. thermomechanical processing based on cold rolling and annealing wasused to produce two different types of austenite: ultrafine grained (ufg) austenite with the averagegrain size of 0.65 μm and coarse grained (cg) austenite with the average grain size of 12 μm....