Determination of Transformation Induced Heat Transfer Coefficients in Mechanical Properties of Powder Metallurgy Steels
2 Abstract: Powder metallurgy has been used for the manufacture of fully dense, which have not reacted composites consisting of a matrix of copper containing 50 -60 vol% particles with negative thermal ZrW2O8 expansion. On cycling between 25 and 300°C, the compounds showed coefficients thermal expansion which varies rapidly with temperature and significantly larger than expected by theory. Improvements in adhesion strength and thermal properties of composite materials have been achieved in atomized copper alloy with small additions of chromium to increase the interfacial bonding in composite Cu / diamond from a nano-sized thin Cr3C2layer.
Fabrication and characterization of americium, neptunium and curium bearing MOX fuels obtained by powder metallurgy process
MOX fuel pellets containing up to 1.4 wt% of Minor Actinides (MA), i.e. Am, Np and Cm, were fabricated to demonstrate the technical feasibility of powder metallurgy process involving, pelletizing and sintering in controlled atmosphere. The compounds were then characterized using XRD, SEM and EDX/EPMA. Dense pellets were obtained which closed porosity mean size is equal to 7 μm. The results indicate the formation of (U, Pu)O2 solid solution. However, microstructure contains some isolated UO2 grains. The distribution of Am and Cm appears to be homogeneous whereas Np was found to be clustered at some locations.
Study on shaping spherical Poly Crystalline Diamond tool by Micro-electro-Discharge Machining and micro-grinding with the tool
Micro-electro-Discharge Machining (Micro-EDM) for shaping of a spherical tool made of Poly Crystalline Diamond (PCD) has been developed for the purpose of enabling a grinding process of a micro-free form surface on hard and brittle materials. Using this spherical PCD tool as a grinding tool, the surface roughness of a minute flat plane (90 × 70 µm), which was ground into tungsten carbide, has 28 nm Rz and 5 nm Ra. This paper describes the capabilities of spherical PCD tool grinding with the following results.