PM 2 Tec 2003: PM industry turning the corner

Abstract

MPIF's 2003 International Conference on Powder Metallurgy and Particulate Materials in Las Vegas attracted 1100 delegates from more than 30 countries. JOSEPH M. CAPUS reviews the event, while JOHN DUNKLEY assesses developments pointing the way to higher density, higher performance PM components.     

Review of the Magnetic Properties of Sintered Iron

Abstract

Throughout the past decade a number of new powder metallurgy processes have appeared which offer con siderable promise for superior aeroengine combustor, blade, and disc alloys. Furthermore, several features of these processes can be exploited for improved material utilization such that total manufacturing costs are contained to combat steep increases in basic alloying element prices. The processes include gas atomization of superalloy powder for critical rotating parts, rotating electrode atomization for titanium powder in similar components, controlled thermomechanical processing of attrited powders to produce oxide dispersion strengthened superalloy sheet and airfoil parts, and finally plasma-sprayed gas-atomized powder for advanced hot-section overlay and thermal barrier coatings. Considerable alloy and process development work has already been undertaken on all these systems by aeroengine material suppliers and advantages accruing in terms of superior properties and/or lower processing costs demonstrated at laboratory level and for some cases also in engine service. PM/0186     

Particulate materials for energy applications

Abstract

A one-day workshop focusing on energy applications, organised by the Particulate Engineering Committee of the Institute of Materials, Minerals and Mining (IOM3) and co-sponsored by the Materials Knowledge Transfer Network (KTN), was held at the Riverside Centre, Derby on 15 May 2013.     

Design and licensing of UKAEA IP 2m box

Abstract

Croft Associates Ltd (Croft) was contracted by the United Kingdom Atomic Energy Authority (UKAEA), Winfrith in 2006 to design, manufacture, test and license an intermediate level waste industrial package transport packaging (UKAEA 2 m Box Design no. 3954) for decommissioning waste from the Dragon and steam generating heavy water reactors at Winfrith. The package had to meet the requirements of the existing UK. Nuclear Decommissioning Authority (NDA) (Nirex) 2 m Box specification. The UKAEA 2 m Box is intended for on-site storage at Winfrith and possibly another site for 50 years and subsequent transport to the NDA repository without further processing. The design of the box closure includes a leak testable sealing system which is capable of being replaced at a later date (e.g. before shipment), by the removal of the lid and replacement of seals remote from the box location. Initially the specification for the UKAEA 2 m Box called for rating for gross weight of 40 t, but this was raised to 50 t as it was realised that the efficient use of the capacity of the box would result in a 50 t gross weight. Two prototype 2 m Boxes were produced; one being provided with 100 mm of concrete shielding, and the other being provided without any shielding. The shielded box was filled with simulated waste and a concrete grout cap fitted and the resulting 50 t package was dropped onto the massive target at Winfrith from a height of 300 mm (this being the regulatory test height). The test showed that the box performed as expected; meeting all requirements. In particular: there was no loss of shielding and no effect on the containment system that would reduce its effectiveness.     

Role of carbon and nitrogen content on microstructural homogeneity in thin slab direct rolled microalloyed steels

Abstract

This paper analyses the effect of carbon and nitrogen content on the austenite microstructural homogeneity before transformation in the thin slab direct rolling of Nb and Nb–V microalloyed steels. The study was made with the help of a microstructural hot working model adapted to the metallurgical peculiarities associated with thin slab direct rolling. The results show that an increase in carbon content from 0·04 to 0·09% in 0·05%Nb microalloyed steels requires a significant increase in the initial rolling temperature in order to avoid the presence of isolated as cast austenite grains prior to transformation. Similarly, an increase in nitrogen content from 30 to 120 ppm does not imply changes as drastic as in the case of carbon. In both situations the changes required in the rolling temperature can be explained by the interaction between post-dynamic softening mechanisms and strain induced precipitation kinetics. In this context, the incidence of different final gauge thicknesses on microstructural homogeneity is evaluated.