Test reports arrive full of technique acronyms, and it is easy to order the wrong test confidently. Here is what the common characterisation families actually answer — so the next time someone proposes a test, you can ask the only question that matters: which decision will this result change?
Composition analysis — "what is it made of?"
Spectroscopic methods measure which elements are present and in what amounts. They answer: is this the specified grade? was the material substituted? what is this deposit or corrosion product made of? Portable methods verify quickly in the field; laboratory methods add precision and the light elements (like carbon) that portable analysers can miss — a distinction that matters when a steel's grade hangs on its carbon content.
Metallography — "what has happened to it?"
A polished, etched cross-section under the microscope reveals the microstructure: the record of the material's thermal and mechanical history. It answers: was it heat treated correctly? has service degraded it? is there cracking below the surface, and does it follow grain boundaries? are inclusions or defects present? Composition tells you what was bought; microstructure tells you what was done to it.
Hardness — the cheapest revealing number
A hardness value correlates with strength and reflects heat treatment, welding effects and service degradation. A hardness traverse across a weld is one of the fastest ways to see whether a procedure was controlled. Cheap, quick, near-non-destructive — and frequently the first number that exposes a problem.
Mechanical testing — "what can it carry?"
Tensile, impact and bend tests measure what design calculations assume: strength, ductility, toughness. They answer whether the material meets its specification and whether embrittlement has stolen the toughness the design relied on. They need material to be sacrificed — part of why test selection and sample location are strategic decisions, not paperwork.
Fractography — "how did it break?"
Reading a fracture surface, from macro photography to high-magnification electron microscopy, identifies the failure mechanism: fatigue's beach marks and striations, ductile dimples, brittle facets, intergranular cracking. This is the core discipline of failure investigation. Fatigue vs overload →
The part that matters: strategy and interpretation
Techniques are commodities; the sequence and the reading are not. Which tests, in what order, on which samples, preserving which evidence — and what the combined results mean for your decision — is where an investigation succeeds or wastes money. That is MTIS's role: we design the programme, coordinate the right specialist partner laboratory for each method, and interpret the results into an engineering answer. How the partner-lab model works →
When to contact MTIS
When you need to know what something is, whether it meets specification, or why its microstructure or properties are wrong — and especially when a set of test results has landed on your desk and you need to know what they actually mean. Characterisation & Testing Coordination → · Start a job request →