Fast, accurate and non-destructive temperature measurement of aluminium

• Heating of slabs, billets and ingots
• Extrusion
  

Prior to forging, rolling or extrusion, aluminium is preheated to the required process temperature. In forging operations, precise temperature control is crucial because the workpiece is heated close to the melting point of aluminium.

To achieve high material throughput rates and short cycle times at the automated press forging line, quick and highly accurate temperature detection is essential to maintaining exact process temperatures.

Temperature is a critical parameter affecting press speed and product quality. Both the billet and the die are preheated and additional heat is generated by friction during the forming process. The aluminium profile at the press exit should not be too hot because this could lead to hot cracks or hot tear formation. In addition, excess temperatures will wear out the die. Nondestructive, fast and reliable temperature monitoring is crucial to achieving and maintaining strict quality control standards.

Aluminium does not radiate thermal energy well. Oxidation can cause the aluminium surface to vary between shiny and matt. Given such circumstances, a standard pyrometer will not able to produce accurate temperature data. The CellaTemp PA 28 and PA 29 were designed especially for temperature measurement of aluminium. It’s spectral sensitivity enables the pyrometer to react significantly lower to light from other sources which might be reflected off of the aluminium. The changing surface characteristics typical of aluminium will not affect the measurement at this particular wavelength. That is why CellaTemp PA 28 / PA 29 is able to accurately detect the infrared radiation of shiny, reflective metals with low emissivity at low temperatures. Depending on the temperature range, the size of the object and the measuring distance, different devices are available. To facilitate focusing, the CellaTemp PA comes equipped with either throughthe- lens sighting, a laser spot light, or an integrated video camera. The pyrometer is infinitely adjustable to ensure superior precision across a wide focusing range starting at 300 mm. The brightly lit display panel indicates the temperature reading and is easy to read from a distance of several meters.