Cu-MgO Composites

Metal matrix composites reinforced with ceramic particles can be interesting for a range of applications due to their strength performance at high temperatures and a relatively low thermal expansion potential.
Manufacturing of Cu-MgO composites critically requires that the raw materials have a very high level of purity (99.5-99.9%) to achieve the desired manufacturing results. Continue reading

The Vacuum Die Casting (VDC) Process: Part One

Vacuum die casted materials have many applications in the automotive industry as well as a number of other commercial industrial sectors.
The main benefits of VDC as opposed to other more traditional methods of casting include a higher quality surface finish, improved mechanical properties and an overall better finished product stability. Continue reading

Iron Spark Plasma Sintering (SPS): Part One

Spark Plasma Sintering (SPS) is a sintering technique which is well matched to mechanically milled materials such as tool steels due to its low temperature and short cycle time.
Tool steels have been specifically manufactured to exhibit exceptionally high strain hardening, a characteristic which can be undone by high temperature sintering processes such as hot isostatic pressing. Continue reading

Superplasticity of Aluminum Alloys: Part Two

Investigations into the superplasticity possibilities of aluminums can lead to many potential gains in finding lighter yet capable materials in terms of strength performance.
This article covers the high-temperature deformation behavior of 5083 at different annealing temperatures and yields some interesting conclusions. Continue reading

Semi-Solid Rheocasting of Alumina Alloys: Part One

Aluminum is well established at the front of the pack with regards to providing the technological answer to the increasing challenges of light weighting whilst maintaining integrity of the material for the desired applications.
Semi solid rheocasting is a development within the casting sector which enables improved quality in die casting without increasing cost. Continue reading

Intercritical Annealing of Ductile Iron: Part One

Heat treatment can be performed on ductile iron to increase strength, wear resistance, ductility, toughness, and/or improve machinability by controlling the matrix microstructure. In F, an intercritical heat treatment starts with partial austenitization in the intercritical region where ferrite and austenite are present. The amount of austenite depends on the chemistry of the alloy and the temperature. Continue reading

High Chromium Cast Iron: Part Two

High chromium cast irons (HCCI’s) exhibit very good mechanical properties and offer benefits for a range of manufacturing applications.
One of the main flexibilities exhibited is the possibility of HCCI’s to have different matrix structures in different treatment states whether it be austenite in casting state, pearlite in annealing state, martensite in quenching state, and tempered martensite in tempering state.
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Microstructures in Austenitic Stainless Steels

Austenitic steels may undergo microstructural changes during short- or long-term exposure to high temperature. In the case of longer ageing times, other precipitates such as intermetallic phases are formed, which are usually accompanied by dissolution of carbides.
The intermetallic precipitations are of great interest not only because they exert influence on the mechanical properties but also because of their strong effect on the corrosive properties.

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The Rheo Casting Process

Defects and anomalies are an everyday challenge within the framework of foundry technologies. As demand for castings with very specialized applications rises, the issue of quality becomes more important.
The Rheo Casting process involves using slurry in a semi solid state with the amount of benefits directly linked to the fraction solid at the time of casting. Advantages can include a reduction in shrinkage and significantly reduced latent heat.
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Ultra Low Carbon Bainitic Steels: Part Two

Although one of the most hotly debated microstructure topics, control of bainitic transformation can lead to a range of diversified gains over the mechanical properties of the finished product.
Specific studies of the relationship between cooling rate and finished cooling temperature show interesting findings related to the distribution of granular bainite, martensite-austenite constituent, bainitic ferrite, and polygonal ferrite.

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