Heat Treatment (In House Facility):
|Quenching||Sudden Quenching in Water at 30 Deg Celsius.|
|Natural Ageing||Upto 5 Hrs|
|Precipitation||Keep in furnace at 165 Deg Celsius for 8 Hrs.|
Heat Treatment is the process whereby controlled heating and cooling is used to alter the physical & mechanical properties of metals without affecting any change in the shape of the objects. Heat treatment process is used to increase material strength and also to improve machining, formability & restore ductility. Heat treatment process allows for the improvement in product performance through improvement in material characteristics.Metallurgy of Heat Treatment of Aluminum Alloys
Aluminum and its Alloys are used in a variety of cast a wrought forms and conditions of heat treatment. Forging, extrusions, sections, etc., are examples of wrought products, while sand, gravity and pressure die castings are generally adopted casting methods.
It has been the practice of Designers to specify heat treatment to enhance mechanical properties, hardness and machinabilty. Only certain Aluminum Alloys containing alloying elements like CU, Si, Mg and Zn in certain specific percentages can be heat treated to have desired mechanical properties. Other non heat treatable alloys can at the most be annealed to facilitate forming operations.
The various alloying elements mentioned above have limited solubility in solid state and this increase with increased temperature.Solution Heat Treatment
This involves heating of Aluminum alloy to a particular temperature for sufficient time so that the alloying elements go into solid solution and forma single phase. The factors which affect the final properties of the alloy are soaking temperature, soaking time and cooling rate.
The Soaking temperature depends on various phases which are present in alloys. Each phase will dissolve in solid solution at different rates. The soaking time is based on the rate of dissolution of alloying elements into solid solution. It also depends on the conditions under which the alloy is cast. Sand cast parts have coarser structure than permanent mould casting. Hence sand castings take time for dissolution of phases necessitating longer soaking time.Commonly used T6 Heat Treatment Process:
For the attention of casting designers:
|1.||Solutionising :||Keep in furnace at 525 Deg Celsius for 8 Hrs.|
|2.||Quenching :||Sudden Quenching in Water at 30 Deg Celsius. .|
|3.||Natural Ageing :||Upto 5 Hrs|
|4.||Precipitation :||Keep in furnace at 165 Deg Celsius for 8 Hrs.|
|5.||Hardness to be achieved between 80-100 BHN|
For highly stressed castings it is usually necessary to use heat-treatable alloy. Full heat treatment involves rapid quenching of castings from high temperature solution treatment. The designer must recognize that this process imposes limitations on the size and complexity of castings and that some precautionary measures, such as the use of cast tie bars, may be necessary to minimize distortion of large or intricate castings. Alternatively, for some castings the use of a less strong alloy not requiring full heat treatment is preferred, the deficiency in strength being overcome by increased scantlings in the casting.
At VJP, we have the capability to undertake these heat treatment processes through our associate vendors. We ensure that the processes are carried out as per the highest standards of quality and as per the specifications of our customers.