UNIT 1 UCM

Views:
 
Category: Education
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

UNIT I INTRODUCTION :

UNIT I INTRODUCTION

Syllabus :

Syllabus Unconventional machining Process Need Classification Brief overview

What is Ucm? :

What is Ucm ?

Conventional Machining Process:

Conventional Machining Process Metal Removal ? Nature of Contact ? Scrap ?

Demerits:

Demerits Disposal of Waste By products of chips Work holding Devices for larger cutting force Heat Generation Not possible without chips

Unconventional Manufacturing process:

Unconventional Manufacturing process Unconventional Manufacturing process Unconventional Machining process or Non Traditional Machining Process Unconventional Forming process

Unconventional Manufacturing process :

Unconventional Manufacturing process Machining process Metal Removal No Direct Contact b/w tool and work piece Forming process Metals are formed Releases large amount of Energy in very short time interval

Need for UCm:

Need for UCm

Need :

Need Machining – produces finished products with high degree of accuracy Conventional machining Utilizes cutting tools (harder than workpiece material). Needs a contact between the tool and workpiece . Needs a relative motion between the tool and workpiece .

Need:

Need The need for higher productivity, accuracy and surface quality Improve the capability of automation system and decreasing their sophistication (decreasing the investment cost) requirements Very hard fragile materials difficult to clamp for traditional machining When the work piece is too flexible or slender When the shape of the part is too complex Internal and external profiles, or small diameter holes.

Classification :

Classification

Unconventional Machining Processes – Based on Energy:

12 Unconventional Machining Processes – Based on Energy

Unconventional Machining Processes – Based Mechanism:

13 Unconventional Machining Processes – Based Mechanism

Unconventional Machining Processes – Based on Energy used for Removal:

14 Unconventional Machining Processes – Based on Energy used for Removal

Unconventional Machining Processes – Based on Transfer of Energy:

15 Unconventional Machining Processes – Based on Transfer of Energy

Mechanical Based Processes:

16 Mechanical Based Processes Working principles Equipment used Process parameters MRR Variation in techniques used Applications AJM WJM AWJM USM

Electrical Based Processes:

17 Electrical Based Processes Working principle Equipment used Process parameters Surface finish & MRR Electrode/Tool Power & Control circuits Tool wear Dielectric Flushing Applications Electrical EDM WEDM

Chemical & Electrochemical Based Processes:

18 Chemical & Electrochemical Based Processes Working principles Etchants & Maskants Techniques of applying maskants Process parameters Surface finish & MRR Electrical circuits in case of ECM Applications CHM ECM ECG ECH

Thermal Based Processes:

19 Thermal Based Processes Working principles Equipment used Types Beam control techniques Applications LBM PAM EBM

Selection Process:

Selection Process

Selection Process:

Selection Process Selection Process is based of following parameters Physical Parameter Shapes to be Machined Process Capability Economic consideration

Physical Parameter:

Physical Parameter Parameter ECM EDM EBM LBM PAM USM AJM Potential, V 5- 30 50-500 200 x 10 3 4.5 x 10 3 250 220 220 Current, A 40,000 15-500 0.001 2 600 12 1.0 Power , kW 100 2.70 0.15 20 220 2.4 0.22 Gap, mm 0.5 0.05 100 150 7.5 0.25 0.75 Medium Electrolyte Die electric fluid Vacuum Air Argon Nitrogen Abrasive grains Work Material M/C diff Tungsten carbide All Mtl All Mtl All Mtl Tungsten carbide HSS

Shapes to be Machined:

Shapes to be Machined Process Machines Holes ( Micro, Small, deep,Shallow ) LBM, EBM,ECM, USM & EDM Precision Work USM & EDM Horning ECM Etching ECM & EDM Grinding AJM & EDM Deburring USM & AJM Threading EDM Profile Cut PAM

Process Capability or Machining Characteristics :

Process Capability or Machining Characteristics Process MRR ( mm 3 /s ) Surface Finish ( μ m) Accuracy ( μ m) Power (kW/ cm 3 / min LBM 0.10 0.4 – 6.0 25 2700 EBM 0.15 - 40 0.4 – 6.0 25 450 EDM 15 - 80 0.25 10 1.8 ECM 27 0.2 -0.8 50 7.5 PAM 2500 Rough 250 0.90 USM 14 0.2 – 0.7 7.5 9.0 AJM 0.014 0.5- 1.2 50 312.5

Process Economy:

Process Economy Process Capital Cost Tool & Fixtures Power Requirement Efficiency EDM Medium High Low High CHM Medium Low High Medium ECM V. High Medium Medium V. Low AJM V. Low Low Low Low USM High High Low Medium EBM High Low Low V. High LBM Medium Low V. Low V. High PAM V. Low Low V. Low V. Low Conventional V. Low Low Low V. Low

Limitation:

Limitation More Expensive Slow Process Commercial

Compiled By D.Vasanth kumar :

Compiled By D.Vasanth kumar

authorStream Live Help