Choosing engineering materials is rarely as simple as selecting the strongest, lightest or most heat-resistant option on a datasheet. Yet many engineering failures, delays, and costly redesigns still stem from exactly that approach - relying heavily on isolated material properties without fully considering how materials behave in real-world conditions.
This article explores some of the most common misconceptions engineers have about materials and performance, and why a more contextual, application-led approach to materials engineering leads to more reliable outcomes.
Engineering Materials Are Not Static Properties
One of the most common misconceptions engineers have about materials is that they are fixed and predictable. When in reality, material behaviour is dynamic. Much like the image above, which illustrates material failing under testing, materials don’t always behave in the manner we expect. Properties measured under controlled laboratory conditions rarely reflect how a part performs once it is printed, assembled, and put into service - where geometry, process variability, and loading conditions begin to dominate
Factors such as layer orientation, internal structure, surface finish and post-processing all influence final performance. With polymer and metal additive manufacturing, the same material can behave very differently depending on how it’s produced.
For engineers, this means that material selection should never be separated from process selection. Engineering materials and manufacturing methods must be considered together if performance expectations are to be met.
Strength Is Not the Same as Performance
Strength figures are often over-prioritised when comparing engineering materials, despite being only one dimension of real-world performance. Tensile strength, yield strength, and hardness are useful indicators, but they are only part of the picture.
In many applications, performance is dictated by a combination of properties, including:
- Impact resistance
- Fatigue behaviour
- Thermal stability
- Wear and abrasion resistance
- Elasticity, compliance, and deformation
For example, a high-strength material may perform poorly under cyclic loading or sudden impact. Likewise, a rigid material may fail prematurely in applications where controlled flexibility or energy absorption is critical - even if it performs exceptionally well in static testing.
Materials and performance are all about balance. Understanding how different properties interact under real operating conditions is far more valuable than focusing on an isolated metric.
The Dynamic Behaviour of Materials is Often Overlooked
While manufacturing influences initial performance, many failures occur because materials behave differently once parts are in use. Very few engineered parts experience purely static loads over their working life. They flex, vibrate, heat up, cool down, and interact with other components. This in-service, dynamic behaviour plays a critical role in long-term material reliability.
Examples of material behaviour under dynamic conditions can include:
- Creep under sustained load
- Fatigue cracking from repeated stress
- Changes in stiffness with temperature
- Damping characteristics during vibration
It’s important to note that high-performance materials are not immune to these effects either. In fact, in some cases, advanced engineering materials can be more sensitive to specific loading scenarios than alternatives.
Engineers who overlook dynamic behaviour risk designing parts that perform well in early testing but fail prematurely in service.
Datasheets Do Not Tell the Whole Story
Material datasheets are essential, but they’re often treated as definitive rather than indicative. In practice, datasheets present idealised values measured under specific test standards. They rarely account for design geometry, print orientation, internal features or real-world constraints.
This is particularly relevant in additive manufacturing, where internal lattices, wall thickness and anisotropy directly affect material performance. Two parts printed from the same engineering material can behave very differently depending on how they’re designed and produced.
A more reliable approach is to use datasheets as a starting point, supported by design for additive manufacturing principles and application-specific testing.
Advanced Engineering Materials Still Need Context
There is a growing assumption that advanced engineering materials automatically deliver superior performance, regardless of application or manufacturing context. While high-performance materials such as reinforced polymers, high temperature plastics, or metal alloys offer clear advantages, they can also introduce trade-offs such as:
- Tighter process control
- More complex post-processing
- Higher costs
- Longer lead times
In some cases, a well-understood standard engineering material can outperform a more advanced option simply because it is better matched to the application and manufacturing process. As such, material selection should always be driven by performance requirements, not perceived material status.
Material Performance is Application-Specific
Another common mistake is assuming that a material that performs well in one application will behave the same way in another. Properties of engineering materials must be assessed against the full operating environment, including:
- Mechanical loads
- Temperature range
- Chemical exposure
- Regulatory or testing requirements
A material suited to a static enclosure may be unsuitable for a functional prototype under repeated load. Likewise, a material chosen for early-stage testing may not scale to low-volume production without changes in performance.
Engineers benefit from treating material selection as an interactive process, refining choices as design maturity, manufacturing constraints, and performance targets evolve together.
Better Material Decisions Come from Collaboration
Many material performance issues arise when decisions are made in isolation. Engineering materials sit at the intersection of design, manufacturing, and application requirements.
Working closely with manufacturing experts who understand both material behaviour and production constraints helps bridge the gap between theory and reality, particularly in additive manufacturing, where design and process decisions are inseparable. Practical guidance on design adjustments, print orientation, and material trade-offs often has a greater impact on performance than switching materials entirely.
For engineers, this collaborative approach reduces risk, shortens iteration cycles, and leads to more predictable outcomes.
Rethinking Materials Engineering and Performance
Engineering materials are complex, and their performance cannot be reduced to a single value or chart. By looking beyond datasheets and considering how materials are made, loaded, and used, engineers can make more informed decisions and avoid common pitfalls.
The National Physical Laboratory captures this well: “Improving the understanding of variability in material properties and providing confidence in materials data is key to enabling innovation and reducing risk.”
Understanding materials engineering and performance is not about choosing the most advanced option. It’s about choosing the right material, produced in the right way, for the right application.
Speak to Truform for Expert Advice
If you’re evaluating engineering materials for a prototype or functional part and you want a second opinion on material choice, performance trade-offs, or manufacturability, speak to Truform. Our team can help you assess materials in the context of your application and manufacturing method, before you commit to production.