3 Fundamentals of press design

Deep drawing and stretch drawing
Titanium and titanium alloys
Material
No.
Rm [N/mm
Rp0,2 or Fields of application,
2 ] ReL [N/mm2 ] A80 [%] examples
chemical equipment
construction, electrodeposition,
aircraft and
Ti 99,8 3.7025.10 290...410 min. 180 30 spacecraft construction,
surgery and orthopaedics:
protheses, bone screws,
implants and splints
Ti 99,7 3.7035.10 390...540 min. 250 22 dito
mechanical engineering,
aircraft and spacecraft
TiAl 6 V 4 F 89 3.7165.10 min. 890 min. 820 6 construction, electrical
engineering, optics, precision
mechanical engineering,
medicine technology, fittings
mechanical engineering,
TiAl 5 Sn 2 F 79 3.7115.10 min. 790 min. 760 6 aircraft and spacecraft
construction, fittings
4.2.3 Friction, wear and lubrication during sheet metal forming
As particularly important areas of tribology, friction, wear and lubrication
have a significant influence on process engineering related to sheet
metal forming. The practice has shown that by a purposeful application
of appropriate die materials, together with process-optimized lubricants,
wear of forming and blanking dies can be significantly reduced.
Friction
Friction plays a major role in sheet metal forming. Friction is the result
of internal deformation of the deformed material and of externally
applied loads. In its different manifestations, friction results in complex
wear mechanisms at the contact surfaces between the die and the workpiece.
During forming and shear cutting operations, sliding friction
conditions apply where lubrication is used. In describing friction in
sheet metal forming, as a rule, the coefficient of friction µ [–] is used
and it is expressed as the friction force divided by the normal force, in
the form:
F / F – or
μ= [ ]
R N
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
179