4. Need for Unconventional Machining
4
• Greatly improved thermal, mechanical and chemical properties of
modern materials – Not able to machine thru conventional
methods. (Why???)
• Ceramics & Composites – high cost of machining and damage
caused during machining – big hurdles to use these materials.
• In addition to advanced materials, more complex shapes, low
rigidity structures and micro-machined components with tight
tolerances and fine surface finish are often needed.
• To meet these demands, new processes are developed.
• Play a considerable role in aircraft, automobile, tool, die and mold
making industries.
5. Need for Unconventional Machining
5
• Very high hardness and strength of the material. (above 400 HB.)
• The work piece is too flexible or slender to support the cutting or
grinding forces.
• The shape of the part is complex, such as internal and external
profiles, or small diameter holes.
• Surface finish or tolerance better than those obtainable
conventional process.
• Temperature rise or residual stress in the work piece are
undesirable.
14. PROCESS SELECTION
14
Based on the following points
1. Physical Parameters
2. Shapes to be machined
3. Process Capability or Machining Characteristics
4. Economic Considerations
20. ADVANTAGES
of UCM
20
High Accuracy and surface finish in process
Less Rejected pieces
Increase productivity
Tool material need not be harder than work piece material.
Easy to machine harder and brittle materials
There is no residual stresses in the machined material
32. Advantages
1. We can cut all kind of materials
2. No heat produced in process , so no thermal damage
3. Very thin and brittle material can be machined
4. Low initial investment
5. Good Surface Finish
6. Intricate holes can be cut in hard and brittle material
33. Dis-Advantages
1. Low MRR
2. Soft Material cannot be machined
3. Machining accuracy is poor
4. Nozzle Wear Rate is High
5. Abrasive Powder cannot be reused
6. Embedding of Abrasive particle in work piece is the high
damage thing in this process
7. It requires Dust Collection System
59. MAGNETOSTRICTIVE TRANSDUCER
.
Change in length is independent of
the direction of the magnetic field
But depend only on the
magnitude of the field and
Nature of the material
66. Definition - Piezoelectric
Piezoelectric transducers are a type of electro
acoustic transducer that convert the electrical
charges produced by some forms of solid materials
into energy.
The word "piezoelectric" literally means electricity
caused by pressure.
70. Advantages – Piezoelectric transducer
Disadvantages – Piezoelectric transducer
1. Piezoelectric quartz is high cost
2. Cutting and shaping of crystal is very complex.
86. Process Parameters
Wear Ratio
1.5 : 1 For Tungsten Carbide Work Pieces
100 : 1 For Glass Work Pieces
50 : 1 For Quartz Work Pieces
75 : 1 For Ceramics
1 : 1 For Hardened tool steel Work Pieces