ISO 4386-2:2019

Overview

ISO 4386-2:2019 - Plain bearings - Metallic multilayer plain bearings - Part 2 describes a destructive tensile test to determine the bond strength between a multilayer bearing metal and its backing for bearing metal layer thicknesses ≥ 2 mm. The method applies to bearing metals based on lead, tin, copper or aluminium and to backings made of steel, cast steel or copper alloys (not cast iron). The test is suitable for both thrust bearings and journal bearings with backing inner diameters ≥ 90 mm and is intended for comparative studies, production control and process qualification.

Key topics and technical requirements

• Test principle: Bond strength RCh = Fmax / A (maximum force divided by bond surface area) measured by a calibrated tensile testing machine.
• Specimens: Two standard specimen geometries - T 100 (for bearing backing diameters 90–200 mm) and T 200 (> 200 mm). Detailed machining sequence and dimensional tolerances are specified to ensure repeatability.
• Layer and lining requirements:
  • Test applies to bearing metal layer thicknesses ≥ 2 mm.
  • Scope notes a minimum additional raw lining thickness of 1 mm for tested layers ≥ 2 mm; machining instructions indicate a raw lining thickness minimum of 3 mm for specimen preparation.
• Apparatus & procedure:
  • Use a calibrated tensile testing machine with dedicated fixture so load acts vertically on the bond surface.
  • Load is steadily increased until fracture; the standard specifies the recommended stress increase rate (approx. 10 N/mm per second).
• Evaluation:
  • Distinguishes absolute and relative bond strength. For certain alloys (Pb, Sn) a characteristic limiting thickness is 6 mm; above that the absolute bond strength is independent of layer thickness.
  • Results are limited by the tensile strength of the tested bearing metal; fractured-surface observations and local defects must be recorded.
• Limitations: Not applicable to bearings with cast iron backing.

Practical applications and users

• Who uses it: bearing manufacturers, materials engineers, metallurgists, testing laboratories, quality control and process-qualification teams, and R&D groups developing multilayer plain bearings.
• Why use it:
  • Production control: verify bond integrity of cast or layered bearings.
  • Process qualification: validate casting, backing preparation and bonding processes.
  • Comparative investigations: study the effect of materials, surface prep, heat treatment, casting and cooling conditions on bond performance.

Related standards

• ISO 4386-1 - for non-destructive ultrasonic testing of the bond between bearing metal and backing (for layer thicknesses ≥ 2 mm).
• ISO 4381 - referenced for tin casting alloys used in multilayer plain bearings.

Keywords: ISO 4386-2:2019, plain bearings, metallic multilayer, bond strength, destructive testing, tensile test, bearing metal, backing, T100, T200, quality control, process qualification.