Thermal Expansion of Stainless Steels: Part One

The coefficient of thermal expansion effectively measures the rate of the material expansion as a function of temperature.
This is a critical measure of the material where the application infers heating and remaining at a fixed dimension for any period of time. 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 Low Superheat Casting (LSC) Process

Low superheat casting is similar to the better known SSM technique which can be applied primarily to produce billets with a low cost advantage.
In the LSC process, the alloy is rapidly solidified and cast with a low pouring temperature which is typically just above the liquidus temperature. Continue reading

Vacuum Brazing: Part Two

A critical step in any brazing process is the successful removal of oxide films before the process begins and the vacuum brazing process is no different.
In order to prepare the mating surfaces for brazing the ‘clean-up’ process needs to be initiated and this typically happens most effectively between 600 and 850°C. 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

Superplasticity of Aluminum Alloys: Part One

It is known that superplasticity refers to the ability of a material to demonstrate under tensile tests very high uniform deformation more than several hundreds percents without visible necking. There are two basic requirements in order to achieve superplastic flow in a polycrystalline material. First, the material must have a very small and stable grain size less than 10 μm. Second, superplasticity is achieved only at relatively high temperatures above 0.5Tm (where Tm is the absolute melting temperature) because superplasticity is diffusion-controlled process. Continue reading

Low Temperature Carburizing of Austenitic Stainless Steel: Part One

Although austenitic stainless steels are among the most commonly applied corrosion resistant steels challenges exist related to their relatively poor surface hardness and wear resistance.
Low temperature carburizing presents an effective solution to these challenges by increasing surface hardness through a carbon rich diffusion zone which does not compromise the corrosion resistance of the material. Continue reading