Thermogravimetric Analysis (TGA)

The group operates a Setaram Setsys Evolution 18 equipment to measure sample mass change as a function of temperature or time. This is particularly useful to study the oxidation properties of materials. The equipment is also capable of simultaneous TGA-DTA measurements up to 1750°C with the appropriate TG-DTA module which we have. Brief details of equipment:

  • Room temperature up to 1500°C
  • Inert argon / air / vacuum / highly aggressive atmospheres
  • Heating rate up to 50 K / min
  • Cooling rate up to 200 K / min
Setaram Setsys Evolution 18 TGA

The equipment is very sensitive and is capable of analyses on samples as small as 5 mm x 5 mm up to 13 mm x 30 mm. Typically, long-term 100-hour TGA tests were carried out to assess the oxidation behaviour of materials. Example of test data generated:

TGA mass gain curves at 800 C.

Mass gain per unit area as a function of time for Ni–Co–Al–Ti–Cr alloys during exposure in a TGA at 800 C; from Christofidou, K.A., Jones, N.G., Hardy, M.C., Stone, H.J., "The Oxidation Behaviour of Alloys Based on the Ni–Co–Al–Ti–Cr System" (2016) Oxidation of Metals, 85 (3-4), pp. 443-458. DOI: 10.1007/s11085-015-9606-8

In addition, we also have a TGA equipment consisting of a Sartorius 4410 micro-balance and a Pyro Therm vertical tube furnace capable of 1500°C. The vertical tube furnace is mounted on a linear vertical sliding mechanism, allowing the stabilised sample (attached to the micro-balance) to be introduced into the hot-zone of the furnace at test temperature. This minimises oxidation effects at lower temperatures and allows the oxidation behaviour of the material at test temperature to be studied more accurately.

Example of test data generated with the Sartorius-equipped TGA:

Isothermal oxidation at 1100°C of CMSX-4 samples without salt and with 40 μg/cm2 and 140 μg/cm2 sea salt deposition; from Pang, H.T, Li, F., Pahlavanyali, S., Edmonds, I.M., Brewster, G., Rae, C.M.F., "Effects of Sea Salt on the Oxidation of CMSX-4® at 1100 °C" Superalloys 2016, M.C. Hardy, E.S. Huron, U Glatzel, B. Griffin,B. Lewis, C. Rae, V. Seetharaman, S. Tin (Eds), TMS 2016, 949-958.