Testing & Laboratory

Materials Testing

A scope heading, not a single list of experiments; The following test families conduct the experiments.

Scope

Test families in Materials Testing

Materials Testingis a scope heading, not a single list of experiments. The following test families carry out the experiments in the scope; A complete list of each family is on its own page.

Materials Testing — What Does This Testing Field Cover?

The section below describes how the field of Materials Testing works. The conditions, sample requirements and acceptance criteria of the individual tests in this field are given on the relevant test pages.

Materials testing determines the identity and behaviour not of the product but of the MATERIAL. The category is the common intersection of the metal, plastics, rubber, composite, textile, ceramic and coating fields.

What distinguishes this category is that the result is not a conformity decision but a DATA SHEET. Tensile strength, hardness, melt flow rate or density alone do not say conforming or non-conforming; the product standard, the supply specification or the design calculation says what these values must be.

Materials testing serves three purposes, and which one it is done for determines the interpretation. INCOMING MATERIAL CONTROL verifies the supplier's declaration. DESIGN INPUT produces numerical data for engineering calculation. FAILURE ANALYSIS investigates whether a failure originated in the material. The same tensile test is read differently in the three contexts.

Sampling and preparation are the invisible half of the result. Specimen orientation in a rolled metal, flow orientation in a moulded plastic and the ply layup in a composite change the result markedly. Product standards therefore also govern the location and orientation of specimens.

A material certificate and a test report are different documents. The certificate is the manufacturer's declaration; independent testing verifies that declaration. In critical applications and in cases of doubt, independent verification is carried out, and some areas of legislation make it mandatory.

Commonly confused in this field

A material certificate is not a test report; it is the manufacturer's declaration.
A result without a stated specimen orientation and location is misinterpreted.
A test specimen and the actual part may not give the same value; machining and moulding have an effect.
The ASTM and ISO counterparts measure the same quantity with different specimens and rates; they are not treated as directly equivalent.

Which decisions these results support