Research · Validation

Validation: tensile testing and indentation plastometry in comparison

Data-based comparison of local i3D values and tensile references for yield strength, tensile strength and local stress-strain logic. Relevant for real parts, small samples, weld zones, additive structures, aluminium die castings and forged components.

What is being compared here

The dataset combines 704 comparison measurements between local i3D values and classical tensile-test references. The focus is on local yield strength, local tensile strength and the question of how reliably the indentation-based method according to DIN SPEC 4864 and ASTM E3499 can be interpreted against tensile testing.

These are exactly the search intents behind clusters such as local material properties, derive yield strength and tensile strength from an indent, local stress-strain curve on the real part and material values from an instrumented indentation.

What the dataset shows

The comparison spans mainly steel, aluminium, stainless steel, titanium, nickel and copper. At alloy-group level, it includes heat-treatable steels, boron steels, spring steels, wrought aluminium alloys and aluminium die castings. That makes the validation relevant for real industrial material families rather than a single narrow lab case.

This matters for materials screening, FEM material input, weld and HAZ evaluation and additive manufacturing. The method is not a simplistic hardness conversion. It is a local, model-based route to material interpretation directly at the relevant zone.

Which properties are reliably comparable

DIN SPEC 4864 and ASTM E3499 address the derivation of local plastic properties from an instrumented indentation and a 3D-based evaluation path. In practice, the relevant outputs are:

  • local yield strength RIp0.2
  • local tensile strength RIm
  • stress-strain curves for local material models and inverse FEM

These are the outputs teams are looking for when they search for local FEM material data, material models from a local part condition or material values from indentation methods for FEM.

Where the method reaches its limit

The method does not replace tensile testing universally. ASTM E3499 clearly focuses on plastic properties and comparable local material values. Fracture elongation, fracture behaviour and full global ductility belong to a different category. That is exactly why validation matters: it shows where the local route is strong and where tensile testing remains necessary.

Why this matters for real parts

In welds, heat-affected zones, additive parts, aluminium die castings and forged components, the critical question is often not the global average value but a small local zone. That is where the combination of indentation testing, local 3D acquisition and inverse FEM becomes valuable for the technically relevant zone.

Interactive validation dashboard

Filter the 704 comparison measurements by metal, alloy group, indenter and test load. The dashboard recalculates deviations, means, bias, spread and 95% confidence intervals directly from the JSON dataset.

704 rows in the full selection.

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Filtered yield strength comparison

Filtered tensile strength comparison

Top metals

    Most frequent alloy groups

      Loads in selection

        Alloy Group Metal Load Indenter RIp0.2 i3D / tensile ΔRIp0.2 RIm i3D / tensile ΔRIm

        Standards and references behind this interpretation

        More research
        Standards framework for local indentation testing

        DIN SPEC 4864

        Method framework

        Defines the technical testing path for local plastic properties from an indentation workflow.

        Additively manufactured cube with local strength indents

        Fraunhofer Enabl3D

        Reference project

        Reference project for data-based quality assurance of additively manufactured metal parts with local mechanical interpretation.

        i3D Inline in a process-near QA environment

        i3D Inline

        Integration

        Bring local material data closer to production, robotics, test cells and release decisions.

        Common validation questions

        How close are i3D values to tensile-test references?

        In this dataset the correlations for yield strength and tensile strength are very high. The key point is not a single showcase value but that the method remains interpretable across many alloys and material groups.

        Which properties can be compared directly?

        The most direct comparisons are local yield strength RIp0.2, local tensile strength RIm and the shape of the stress-strain curve in the plastic range. Fracture elongation and fracture behaviour should be treated separately.

        Does indentation plastometry replace every tensile test?

        No. The method is strongest for local questions on real parts, small zones, welds, additive structures, die castings or forged components. Tensile testing remains relevant for global reference paths, fracture behaviour and full tensile workflows.

        Why is this relevant for real parts and small zones?

        Because critical zones are often not where classical tensile coupons are taken from. That is why local material data are so valuable for welds, HAZ, additive structures, cast skins, edge zones and small fasteners.

        How do local values move into FEM or material models?

        The instrumented indent is used to derive local yield strength, local tensile strength and the plastic shape of the stress-strain curve. These outputs can be transferred into FE input for weld zones, gradients, casting skins or other local material states.