Hot Forming

Hot forming is a range of processes developed specifically for the forming of high temperature alloys.

Hot draw forming
The hot forming process is similar to traditional cold forming but involves heating the tool and component. Temperatures range from 600˚C to 980˚C depending on customer specifications and the material used. The hot sheet metal is brought into contact with the hot die whilst the hot punch descends into the die and shapes the part. The part is then held under forming pressure for a period.

Hot die quenching
The sheet metal is heated in an oven and then formed in a cold die/punch tool.

Hot brake pressing
Hot brake pressing is similar to traditional cold brake pressing but the blanks are preheated in the oven before pressing in the brake press.

Senior Aerospace Thermal Engineering is one of the leading specialists in this technology and we have powerful capabilities in hot forming and hot draw forming of metals for aerospace, including double and triple action hot draw forming. Currently we operate 6 presses with a full range of size, pressure and temperature capability.

Hot forming provides a number of advantages over other forming methods including cold forming, superplastic forming etc.

Accurate forming: High definition of form is possible and with tooling and part both heated to temperature a superior accuracy of form is possible avoiding springback

Complex shapes: The use of a controllable gripping force around the form die, enables more complex shape and/or tight radii to be formed without splitting or local thinning – a result traditionally achievable by Superplastic Forming (SPF), but a fraction of the cost

Higher surface profile tolerances: Hot draw forming is ideal for the forming of titanium and other high-temperature alloys as it inhibits cracking and forms to much higher surface profile tolerances than cold draw forming

Consistent thickness: The process avoids the thinning or necking of the sheet by drawing the margin of the sheet inwards smoothly rather than thinning.

Resistance to cracking: Hot formed titanium is more resistant to cracking and this reduces waste and creates a part which conforms to drawings and performs more safely and effectively

Strength: Finished component strength is as good as a forged component

Lower cost: Hot forming provides a lower cost alternative to superplastic forming (SPF). A thinner starting sheet thickness is possible, forming times are much shorter.

Materials used

• Titanium and its alloys (Ti6/4, TI-6242, Ti230, TiCP)
• Nickel and Cobalt base alloys – Nimonic (N75), Inconel (IN718, IN625)

Approvals

Senior Aerospace Thermal Engineering holds approvals from all of our major customers for hot forming including:

• Airbus (ABP3-1117, ABP6-3202)
• Aircelle (HPTR0072A)
• BAe systems (R25-9027)
• Rolls-Royce (RPS627)
• GKN (Volvo)VOLS 10067154, 10073265)
• ITP (SPE-027)
• Bombardier (P.Spec 231 PPS 1.36)