01-05-2010, 03:37 PM
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micro scale milling
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[/size][/font][font=Times New Roman][size=medium]
send me this topic
pdf file doc file
and powerpoint file please send me immedieatly
07-10-2010, 11:01 AM
[attachment=5252]
Introduction
Milling is the fabrication technology of choice for a wide range of complex three-dimensional components, in a wide variety of materials. It is most commonly used to produce features ranging in size from a few millimeters up to thousands of millimeters. Small diameter milling cutters (~0.10 mm dia.) are widely and inexpensively available, and are mostly used to create small features in graphite EDM electrodes used to manufacture injection molding dies. There exists a wide variety of important applications for micro- and meso-scale mechanical systems which require high-strength materials and complex geometries that cannot be produced using current MEMS fabrication technologies. Micro-milling [9] is one fabrication technology with potential to fill this void by adding the capability of free form machining of complex 3D shapes from a wide variety and combination of engineering alloys, and other materials.
Micro‐milling Machining Requirements
With multiple elements working in tandem, a machine is only as good as its weakest individual component. Less forgiving than traditional milling, micro‐milling requires each machine component to be suitable for the unique requirements
of the task.
Machine Geometry
Machine geometry plays an important role in the machine’s overall performance. It determines the machine’s stiffness, accuracy, thermal stability, damping
properties, throughput, and ease of use. The most popular vertical machine
geometry types are bridge and C‐frame construction. With the spindle or Z‐axis being the only moving axis, a C‐frame construction offers the best stiffness
qualities. Since stiffness directly affects accuracy, this design is highly suitable
for micro‐milling. Stiffness does decrease in C‐frames as the length of Z‐travel increases. Therefore, the ideal C‐frame construction is one that balances the
need to hold tight tolerances required for micro‐milling and the length of
Z‐travel.
Machine Construction
One of the challenges when milling delicate and accurate parts is minimizing
vibrations. Machine tools with greater damping will absorb more of the
vibrations induced by cutting. Many machine frames are constructed using
cast iron or steel weldments. Unfortunately, these types of materials are not
suitable for micro‐milling. The most suitable machine frame material for
micro‐milling is polymer concrete, which provides up to ten times higher
absorption of vibrations than cast iron. Polymer concrete also provides
superior dynamic and static rigidity and has substantially better thermal
stability than cast ion, all crucial properties for small part accuracy.
Micro-scale milling
Introduction
Milling is the fabrication technology of choice for a wide range of complex three-dimensional components, in a wide variety of materials. It is most commonly used to produce features ranging in size from a few millimeters up to thousands of millimeters. Small diameter milling cutters (~0.10 mm dia.) are widely and inexpensively available, and are mostly used to create small features in graphite EDM electrodes used to manufacture injection molding dies. There exists a wide variety of important applications for micro- and meso-scale mechanical systems which require high-strength materials and complex geometries that cannot be produced using current MEMS fabrication technologies. Micro-milling [9] is one fabrication technology with potential to fill this void by adding the capability of free form machining of complex 3D shapes from a wide variety and combination of engineering alloys, and other materials.
Micro‐milling Machining Requirements
With multiple elements working in tandem, a machine is only as good as its weakest individual component. Less forgiving than traditional milling, micro‐milling requires each machine component to be suitable for the unique requirements
of the task.
Machine Geometry
Machine geometry plays an important role in the machine’s overall performance. It determines the machine’s stiffness, accuracy, thermal stability, damping
properties, throughput, and ease of use. The most popular vertical machine
geometry types are bridge and C‐frame construction. With the spindle or Z‐axis being the only moving axis, a C‐frame construction offers the best stiffness
qualities. Since stiffness directly affects accuracy, this design is highly suitable
for micro‐milling. Stiffness does decrease in C‐frames as the length of Z‐travel increases. Therefore, the ideal C‐frame construction is one that balances the
need to hold tight tolerances required for micro‐milling and the length of
Z‐travel.
Machine Construction
One of the challenges when milling delicate and accurate parts is minimizing
vibrations. Machine tools with greater damping will absorb more of the
vibrations induced by cutting. Many machine frames are constructed using
cast iron or steel weldments. Unfortunately, these types of materials are not
suitable for micro‐milling. The most suitable machine frame material for
micro‐milling is polymer concrete, which provides up to ten times higher
absorption of vibrations than cast iron. Polymer concrete also provides
superior dynamic and static rigidity and has substantially better thermal
stability than cast ion, all crucial properties for small part accuracy.
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