The Nitrocarburizing Process: Part Three

Nitorcarburizing is typically performed on steel components to improve surface hardness of the material via nitrogen dispersion.
One noteworthy finding however suggests that the corrosion resistance of the treated specimen was less than that of the control and untreated part. Continue reading

Boronization of Titanium Alloys

Boronizing is a surface treatment by which boron atoms are diffused into the surface of the metal in quantities exceeding the solubility limit.
Hardness is improved and thus wear resistance increased as well as a number of other advantages such as corrosion and oxidization resistance. Continue reading

Steel Bending

There are five typical methods of bending currently used in industry today: rolling, incremental bending, hot bending, rotary-draw bending, and induction bending.
Although ISF is generally very slow, it is of interest because no or only a simple and cheap tool is required, making the process ideal for small-series production. Continue reading

The Nitrocarburizing Process: Part Two

Nitrocarburizing is a surface hardening process which has several key advantages related to the efficiency in application and also in terms of producing a consistent and stable finished product.
The micro-hardness of surface treated materials using nitrocarburizing can have an increased surface hardness at a ratio of 1.3 to 1.5. Continue reading

The Nitrocarburizing Process: Part One

Nitrocarburizing, by definition, is a thermochemical treatment that is applied to a ferrous object in order to produce surface enrichment in nitrogen and carbon which in turn form a compound layer.
The composition, function and control of the furnace atmosphere are of crucial importance for the result of all hardening and thermochemical operations. 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

Principles of Heat Treating of Steels

Steels can exhibit a wide variety of properties depending on composition as well as the phases and micro-constituents present, which in turn depend on the heat treatment.
The basis for the understanding of the heat treatment of steels is the Fe-C phase diagram. It actually includes two diagrams; the stable iron-graphite diagram and the metastable Fe-Fe3C diagram. The stable condition usually takes a very long time to develop, especially in the low-temperature and low-carbon range, and therefore the metastable diagram is of more interest.

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Precipitation Hardening of Aluminum Alloys

Precipitation hardening, or age hardening, provides one of the most widely used mechanisms for the strengthening of metal alloys. The strongest aluminum alloys (2xxx, 6xxx and 7xxx) are produced by age hardening.
In order for an alloy system to be able to be precipitation-strengthened, there must be a terminal solid solution that has a decreasing solid solubility as the temperature decreases. The precipitation-hardening process involves three basic steps: solution treatment, quenching and aging.

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Strain Ageing of Steel: Part Two

Strain ageing can have a serious detrimental effect on low carbon structural steels and so two material examples are examined to see how different pre-strain and ageing conditions affect material mechanical properties.
A carbon steel (40% martensite) and a microalloyed steel (20% martensite) were both treated under the same parameters and then the UTS and stress strain curves were evaluated to gain some valuable conclusions.

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