Influence of Microstructure on Mechanical Properties and Damage Initiation of Bainitic Steels in Railway Applications

In this PhD thesis, we investigated possible steel candidates for use in railway crossings in order to reduce the damage in them. Pearlitic R350HT together with Bainitic grades including CrB, B1400 and carbide free B360 were investigated for their mechanical properties such as ultimate strength, yield strength, ductility and hardness. The...

Applying multi-pass friction stir processing to refine the microstructure and enhance the strength, ductility and corrosion resistance of WE43 magnesium alloy

Magnesium alloys have many unique properties, mostly benefitting from the low density of magnesium. However, they are not competitive, when compared with other lightweight materials, such as aluminum alloys, particularly in ductility and corrosion resistance. There is a strong need to improve the mechanical properties and corrosion resistance...

A high pressure die cast magnesium alloy with superior thermal conductivity and high strength

Thermal conductivity is a key parameter for high performance material needed for electronic devices. While most commercially used Mg foundry alloys exhibit low thermal conductivities. In this work, we developed an Mg–3RE–0.5Zn alloy that is suitable for high pressure die cast (HPDC) ultrathin wall cellphone components. The thermal...

Applicability study of pulsed laser beam welding on ferritic–martensitic ODS eurofer steel

Pulsed laser beam welding was used successfully to join the oxide dispersion-strengthened (ODS) Eurofer steel. The joining was conducted with a laser power of 2500 W and a pulsed duration of 4 ms. With the filler material being used, a minor material loss and microvoids were observed in the joint. The microstructure of the fusion zone...

Spark plasma sintering of Stellite®-6 superalloy

This paper aims at studying microstructure and mechanical properties of spark plasma sintered (SPSed) Stellite®-6 cobalt-based superalloy. SPS is a sintering technique, based on a relatively fast resistance heating using a pulsed current. Fast sintering process, associated with minimum grain growth, results in excellent mechanical properties....

The microstructural evolution and elemental distribution of a 3rd generation 1 GPa advanced high strength steel during double pulse resistance spot welding

This paper presents the effects of double pulse resistance spot welding (RSW) on the microstructural evolution, elemental distribution and mechanical properties of a 3rd generation 1 GPa advanced high strength steel (AHSS). In order to investigate the effect of double pulsing, the steel was exposed to single and various double pulse RSW...

A comprehensive investigation of the strengthening effects of dislocations, texture and low and high angle grain boundaries in ultrafine grained AA6063 aluminum alloy

The effect of equal channel angular pressing (ECAP) on the microstructure and mechanical properties of AA6063 aluminum alloy was investigated. For this purpose, samples of AA6063 aluminum alloy were deformed up to 10 passes using ECAP and the evolution of microstructure, texture and dislocation density was investigated. It was found that the...

Internal curing of alkali-activated slag-fly ash paste with superabsorbent polymers

This study investigates the influences of internal curing on reducing the autogenous shrinkage of alkali-activated slag/fly ash (AASF) paste. The influences of internal curing with superabsorbent polymers (SAPs) on the reactions and microstructure of AASF paste are investigated. It is found that the SAPs absorb liquid mainly before the...

Effect of mechanical alloying and spark plasma sintering on the microstructure and mechanical properties of ODS Eurofer

Oxide dispersion strengthened (ODS)Eurofer steel was prepared via mechanical alloying (MA)and spark plasma sintering (SPS). Different combinations of MA and SPS parameters were adopted in order to optimise the fabrication process. The experimental results show that the sample milled for 30 h, sintered at 1373 K at a pressure of 60 MPa has...

Microstructure, mechanical, and corrosion properties of Zr_1-xCr_xB_y diboride alloy thin films grown by hybrid high power impulse/DC magnetron co-sputtering

We study microstructure, mechanical, and corrosion properties of Zr_1-xCr_xB_y coatings deposited by hybrid high-power impulse/DC magnetron co-sputtering (CrB₂-HiPIMS/ZrB₂-DCMS). Cr/(Zr + Cr) ratio, x, increases from 0.13 to 0.9, while B/(Zr + Cr) ratio, y, decreases from 2.92 to 1.81. As...