The initial thermal operation applied to aluminum prior to hot working is referred to as ‘preheating’. One of the principal objectives is improved workability. This process precedes hot rolling, extrusion or machining, resulting in variations in the shape of the product. Furnaces used for homogenizing can also vary depending on the product. Ingots, slabs, billets and logs are the most common products. Continuous, pusher and batch furnaces are the most widely-used by the industry, where temperatures are up to 650°C (1202°F).
Monitor the heat treatment process in various furnace types and products in necessary to achieve homogenous heating across the load. Uniform heating of the load eliminates product re-work rates and furnace downtime, while increasing production efficiency. Product profiling ensures conformance to heat treatment guidelines and certain specifications, such as aerospace (AMS2750) and automotive (CQI-9).
To produce aluminum strips, such as those used in window and door frames, large aluminum billets are heated to 480ºC (900ºF) and placed in a large hydraulic press. The aluminum is then extruded through various shaped dies. Billet temperatures need to be maintained to ensure billets are not too cold or hot as they enter the die. Additionally, the temperature of the extruded aluminum strips must be carefully controlled during the extrusion. IR temperature measurement is used to control billet temperatures into the die, as well as the speed of the extrusion exiting the die. If the temperature is incorrect, the metal properties of the aluminum can be affected – especially, the tensile properties.
- Monitor product and furnace thermal cycles simultaneously, and take corrective actions by identifying any cold or hot spots across the load.
- Guarantee product quality by monitoring the heat treat cycle and create reports for traceabilty
- Prove conformity to special heat treatment specifications, such as AMS2750 and CQI-9
- Monitor furnace performance over time and foresee issues before they occur, especially after routine maintenance or repair
- Increased productivity and improved die life through tighter temperature control
- Improved billet quality with continuous temperature monitoring