ISO 19095-5:2023

Overview

ISO 19095-5:2023 specifies a laboratory method to measure the fracture energy of plastic–metal joints. The standard targets interfacial adhesion performance for joints made by adhesive bonding, direct joining of thermoplastics (injection or compression moulding) or similar techniques. It provides a repeatable test to compare adhesives, surface treatments, bonding conditions and environmental effects - but explicitly not for engineering design use.

Key topics and technical requirements

• Test objective: Quantify interfacial fracture energy (energy per unit width) and characterize failure behaviour of plastic–metal assemblies.
• Specimen geometry: Metal and plastic plates nominally 2.0 mm ± 0.1 mm thick; specified specimen layout includes a controlled precrack and defined joining width. Recommended nominal crack length a such that 0.45 < a/W < 0.55 and joining width e preferably W/2.
• Precrack formation: Created by non-stick coating or inserting a PTFE film (recommended thickness 50–100 µm) between adherends to act as a crack initiator.
• Adhesive layer control: For adhesive-bonded specimens the adhesive layer should be < 1 mm and thickness variation within a joint and between joints limited to ±20%.
• Loading and measurement:
  • Test machine meeting ISO 5893 requirements.
  • Load indicator accuracy ~1% and low inertia lag at test speeds.
  • Displacement measured at load points with accuracy ~1% (machine stroke transducer or external gage). Machine compliance compensation required (see ISO 9513).
  • Fracture energy is determined by integrating the load–displacement curve up to fracture initiation (W) and normalizing by joining width (wF = W/eF).
• Fixture and validation: Load blocks bonded to specimen, correct pin loading, failure patterns monitored and tests invalidated if specimen detaches from load blocks before interfacial fracture.
• Supporting clauses: Conditioning, test procedure, evaluation, failure pattern classification, precision and test reporting requirements are included.

Applications and users

Who uses ISO 19095-5:2023:

• Materials and adhesives R&D teams evaluating adhesion technologies.
• Quality-control and testing laboratories comparing surface treatments, adhesives or bonding parameters.
• Automotive, aerospace and electronics manufacturers qualifying lightweight plastic–metal assemblies.
• Suppliers demonstrating environmental effects on bond durability.

Practical benefits:

• Standardized method for comparative ranking of adhesives and processes.
• Reproducible data for process optimization, surface treatment selection and qualification testing.
• Clear specimen preparation and measurement criteria to reduce test variability.

Related standards

• ISO 19095 series (Parts 1–4) - other aspects of plastic–metal joint evaluation.
• Normative references cited in the standard: ISO 291 (conditioning), ISO 5893 (test equipment), ISO 10365 (failure pattern designation), ISO 17212 (surface preparation).

Keywords: ISO 19095-5:2023, fracture energy, plastic–metal assemblies, interfacial fracture, adhesion testing, adhesive bonding, injection moulding, load–displacement integration, precrack.