Metal Analysis and Testing

XPS or ESCA Surface Analysis:

  • Surface contamination detection and identification
  • Surface oxide chemistry
  • Identification of corrosion products
  • Surface segregation of elements in alloys; carbon, sulfur, and phosphorus being examples in addition to metal elements
  • Depth profile elemental analysis to measure graphitic carbon and carbide concentrations as a function of depth
  • Determine the chemistry of anodized surfaces
  • Determine cause of adhesive bond failures on metal surfaces
  • Examine the surface chemistry of metal particles prior to sintering for powdered metallurgy

A carbide and nitride treated titanium alloy surface whose elemental and chemical composition was determined by XPS and argon ion sputtering as a function of depth.

Electrochemical Analysis and Corrosion Testing:

FTIR or Infrared Spectroscopy Analysis:

  • Identify organic coatings on metal surfaces
  • Identify organic contaminants on metal surfaces
  • Identify carbonate, sulfate, nitrate, nitrite, phosphate, and hydroxide layers on metal surfaces

DSC Analysis:

  • Determine alloy melting temperature and the heat of fusion if the melting point is below 725°C
  • Measure the heat capacity
  • Determine temperature and exothermal energy of intermetallic phase formation
  • Determine temperature of crystalline structural (shape-memory included) or magnetic phase transformations (curie temperatures)
  • Determine temperature and energy of a precipitation reaction such as those in many aluminum alloys

TGA Analysis:

  • Measure rate of gas reaction with metal as a function of temperature
  • Determine the Curie temperature of magnetization of ferromagnetic materials

TMA Analysis:

  • Measure the rate of thermal expansion as a function of temperature
  • Measure the melting point if it is below 800°C
  • Measure the rate of surface layer growth due to reaction with gas as a function of temperature
  • Determine the temperature of a structural phase change

SEM Analysis:

  • Image surface morphology
  • Determine fracture mode
  • Determine crystalline domain sizes
  • Measure phase distributions and identify phase types
  • Examine oxide structure and growth modes
  • Image wear effects
  • Examine growth modes of deposited films

Cross Section Analysis:

  • Determine cracking modes
  • Determine inclusion content
  • Examine for voids
  • Examine structures for design integrity

Metallographic Analysis or Metallography:

  • Examine grain sizes and shapes
  • Examine phase distribution and identify type
  • Examine coating defects such as holes, pores, and cracks
  • Measure density and type of inclusions
  • Measure density and size of voids
  • Measure the thickness of oxide or surface treatment layers
  • Examine solder and braze joint cross sections for defects
  • Examine the heat-affect zone near welds and brazed joints
  • Determine cracking modes in metals (transgranular, intergranular, etc.)
    [Example: Cross Section Analysis with Intergranular Corrosion]
  • Examine grain by grain variations of oxide thickness on highly oxidized metal surfaces
  • Examine the onset of corrosive reaction or pits

An anodized aluminum sheet surface is shown above as prepared for adhesive bonding.  No primer has been applied to this surface, though one is before adhesive bonding is performed.

Pinhole corrosion in copper tubing revealed by Nomarski phase interference contrast microscopy.

Several examples of metallographic analysis are discussed on this page.

Profilometry or White Light Interference Microscopy:

  • Measure surface roughness