Porosity is a major concern in the production of light metal parts. This work aims to identify some of the mechanisms of microporosity formation during the gravity-poured castings of magnesium alloy AE42. Two graphite plate molds and a ceramic cylindrical mold were selected to produce a wide range of cooling rates. Temperature data during cooling was acquired with type K thermocouples at 60 Hz ...

In this work, Al-B₄C nanocomposites were produced by microwave sintering and followed by hot extrusion processes. The influence of ceramic reinforcement (B₄C) nanoparticles on the physical, microstructural, mechanical, and thermal characteristics of the extruded Al-B₄C nanocomposites was investigated. It was observed that the density decreased and porosity increased with an increase in B₄C cont...

A method is presented to use a dimensionless form of the well-known Niyama criterion to directly predict the amount of shrinkage porosity that forms during solidification of metal alloy castings. The main advancement offered by this method is that it avoids the need to know the threshold Niyama value below which shrinkage porosity forms; such threshold values are generally unknown and alloy dep...

This paper deals with the role of the porosity on the aerodynamic behavior of two civil structures: the Spire, a tall slender tower 80.44m high, and the buttresses of a tall building. The Spire is an original architectonic complement. Its covering, made of perforated steel plates, forms and intricate three-dimensional spiral characterized by five different diameters. The buttresses connect the ...