Strength, hardness, wear and fracture analysis (fractography)

Our activities focus on the determination of mechanical properties of brittle materials (glasses, glass ceramics, ceramics) and their composites and on estimations of lifetime and reliability. Besides standardized strength testing, application-oriented test methods are developed and validated.

Fracture analysis of the tested samples in combination with the strength test results are a reliable basis for continuous improvement and problem solving in production processes and for the development of new products.

We offer:
  • Performance of strength tests (standardized and custom-designed) incl.
    » Statistical data analysis
    » Estimation of product lifetime and reliability
  • Fracture analysis (fractography)
  • Indentation measurements to determine hardness, stiffness and elasticity of brittle materials and coatings
  • Determination of scratch resistance and scratch tolerance, surface abrasion and wear due to mechanical load
  • Determination of adhesion of coatings on solid surfaces
  • Test of wettability and functionality of solid material surfaces and powders (surface energy, contact angle), determination of the surface tension of fluids
  • Reliable results guaranteed by accredited methods according to standard DIN EN ISO 17025
Example 1: Bending strength according to standard method
Determination of the surface strength of flat glasses and glass ceramics according to DIN EN ISO 1288-5 (ring-on-ring test).

The conclusions drawn from the statistical evaluation of the fracture stresses provide a fundamental understanding of the strength factors relevant in production, treatment and handling processes.
Example 2: Bending strength of ultrathin glass
Determination of the surface strength of glasses and glass ceramics by application of a special application-oriented method. The fracture strength is determined from finite element simulations in dependence on the position of the fracture origin. Further data evaluation is performed similar to standard strength methods (e.g. Weibull analysis).
Example 3: Fracture analysis (fractography)
Analysis of fracture incidents of glasses and ceramics, also as a scientifically sound expert opinion in the context of warranty claims and liability claims (picture: nickel sulfide inclusion in soda lime glass which led to the destruction of a glass panel).
Example 4: Indentation measurement
Indentation measurements for the evaluation of hardness (Knoop, Vickers, Martens) and elastic-plastic properties (stiffness, elasticity) of glasses, glass ceramics and ceramics.
Example 5: Adhesion and wear
Quantitative determination of adhesive properties of coatings by application of a constant or progressive scratch load; scratch resistance and tolerance of coatings and bulk materials; determination of friction coefficients.
Example 6: Wettability
Evaluation of the contact angle and surface energy of solid surfaces and powders by wetting with different fluids (polar and non-polar).

  • Quasi-static strength
    • Tension/compression (uniaxial),
    • Bending (2 Pt., 3 Pt., 4 Pt., ring-on-ring, special applications)
    • Burst pressure (homogeneous internal pressure)
  • Dynamic strength
    • Ball drop tests
    • Pendulum impact tests
    • Thermal shock tests
  • Statistical evaluation of strength results
  • Lifetime
    • Climatic storage, weathering (also cyclic)
    • Shelf life with radiation (UV, sun light)
  • Fractography
  • Material properties
    • Indentation measurements (hardness: Vickers, Knoop, Martens, indentation modulus, elastic part, nano hardness of coatings, crack generation(„crack initiation load“)
    • KIc (fracture toughness) with Single Edge Pre-cracked Beam (SEPB) method
    • n-value (crack propagation) with Double Cleavage Drilled Compression (DCDC) method
  • Mechanical durability
    • Abrasion tests (linear with solid abrasive material or circular with loose abrasion grain)
    • Scratch resistance and tolerance to scratch load with sharp indenter
    • Adhesive strength of coating with scratch load with ball indenter
  • Wetting properties
    • Contact angle and surface energy of solid surfaces by means of Drop Shape Analysis
    • Surface tension of fluid by Wilhelmy-plate method

  • Strength determination
  • Shelf life estimation
  • Process analysis and process improvement (manufacturing and handling of glass and glass products)
  • Mechanical characterization of brittle materials and coatings
  • Identification of fracture cause
  • Determination of bonding properties of surfaces and fluids with contact media (for example cleaning condition of surfaces, functionality of coatings, gluing capability)

Your Contact:

Inge Burger
Phone:+49 (0)6131/66-7223