Engineering the Future
MATERIALS ENGINEERING  
MCT Faculty
MCT home
COMPONENT FAILURE MUSEUM

The main sections of the museum are listed below;

Metal Fatigue
Manufacturing Faults
Bicycle Components
Corrosion
Polymers
Composite Materials

Tools of the trade, some ways to investigate problems;
Photoelasticity
Dye penetrant testing

Glossary
of materials engineering terms

 

Glossary of materials engineering terms

ABS;

an abbreviation for Acrylonitrile-Butadiene-Styrene

Accelerated fatigue test;

a test which applies a cyclic loading schedule, which can be of varying frequency and / or amplitude, to a machine or component simulating its loading in service, but at a higher rate, to determine its safe fatigue life before it is reached in service.

Alloy;

a mixture of atomic species exhibiting metallic properties and usually prepared by adding other metals or non-metals to solvent metal in the liquid state. But may also be formed from sintered powders or by by intimate mixing by mechanical means. They may be single or multiple phase where the phases exist as pure elements, solid solutions or intermetallic compounds.

Annealing (Steel);

Heating to, and holding at a suitable temperature, followed by relatively slow cooling. The purpose of annealing may be to remove residual stresses, to soften the alloy, to improve machinablility, to improve cold working properties, or to obtain a desired structure.

'beach marks';

'beach marks' highlight advances of a fatigue crack and are shown by changing conditions at the crack front of stress or environment. Hence periods of rest when rainwater etc. can ingress and highlight them as do changes in load or frequency. (Image)

Brazing;

a method of joining metal parts together by fusing a layer of brass or other copper alloy between the adjoining surfaces. A red heat (700-800°C) is necessary and a flux used to protect the metal from oxidation.

Cold working;

altering the shape or size of a metal by plastic deformation. Processes include rolling, drawing, pressing, spinning and extruding. It is carried out below the recrystallisation point usually at room temperature. Hardness and tensile strength are increased with cold working whilst ductility and impact values are lowered. Cold rolling may significantly improve surface finish.

Corrosion;

follow this link for an explanation of corrosion.

Corrosion fatigue;

When chemically reactive agents can penetrate into fatigue cracks they can accelerate crack advancement. The chemical condition within the crack can be more aggressive than on the free surface. Even if the metal surface at the crack tip passivates (forms an inert barrier) the next fatigue loading can crack the brittle deposit and reactivate the whole process.

DSC; Differential Scanning Calorimetry

This technique takes advantage of the fact that whenever a material undergoes a change in physical state, such as melting or transition from one crystalline form to another, or whenever it reacts chemically, heat is either absorbed or liberated. Many such processes can be initiated simply by raising the temperature of the material.
The instrument determines the enthalpies of these processes by measuring the differential heat flow required to maintain a sample and an inert reference at a given temperature, usually in the form of a pre-programmed thermal cycle.
Useful information such as melting points, glass transitions, degree of crystallinity, presence of impurities etc. can be derived from the data obtained.

Back to Glossary List

 

 
 
© 2005 Materials Engineering - Page last modified 18-Dec-2007