11-08-2014, 02:35 PM
SEMINAR ON HIGH SPEED MACHINING
HIGH SPEED MACHINING.ppt (Size: 640 KB / Downloads: 77)
DEFINITION OF HSM
Carl Salomon assumes that
“At a certain cutting speed which is 5-10 times higher than in conventional machining the chip removal temperature at the cutting edge will start to decrease”
DEFINITIONS
High cutting speed machining
High rotational speed machining
High feed machining
High speed and feed machining
High productive machining
Finally,
“HSM is a powerful machining method that combines high feed rates with high spindle speeds, specific tools and specific tool motion.”
APPLICATION AREAS
Industry which deals with the machining of Al to produce automotive components, small computer parts or medical devices
Aircraft industry involves machining of Al often with thin walls
Die mould industry which requires dealing with finishing of hard materials .
Used to machine such parts as die casting dies, forging dies, injection moulds and blow moulds, milling of electrodes in graphite and copper, modeling and prototyping of dies and moulds
MACHINING SYSTEM
MACHINE TOOLS
3-axis horizontal and vertical milling machines
CNC 4-axis milling machine offers the option of tilting the milling cutters to improve the cutting conditions
5-axis machine with inter changeable spindle units allow to rough, semi finish and finish with a single set up.
CUTTING TOOLS
TiN and TiCN coated Carbide for materials with hardness less than 42 HRC
TiALN coated Carbide for materials with hardness 42 HRC and above
For special applications like hard turning (HRC 60-65) PCBN is used
Cubic boron nitrite (CBN) and ceramic for cast iron
Poly crystalline diamonds (PCD) and Cermets are used for aluminum
CONCLUSIONS
HSM is not simply high cutting speed .It should be regarded as a process where the operations are performed with very specific methods and precision equipment
HSM is not necessarily high spindle speed machining. Many HSM applications are performed with moderate spindle speeds and large sized cutters
HSM is performed in finishing in hardened steel with high speeds and high feeds often with 4-6 times conventional cutting speeds
HSM is high productive machining in small sized components in roughing to finishing and in finishing to super finishing in components of all sizes.
Even though HSM is known for a long time, the research are still being developed for further improvement of quality and optimization of cost.