types of cutting Tool wear mechanisms.docx
- 1. Course code ME3493 Course name Manufacturing Technology Year/sem 2/4 Unit no 1 Course Instructor: M.Karthikeyan AP/Mech UNIT 1 MECHANICS OF METAL CUTTING Mechanics of chip formation, forces in machining, Types of chips, cutting tools – single point cutting tool nomenclature, orthogonal and oblique metal cutting, thermal aspects, cutting tool materials, tool wear, tool life, surface finish, cutting fluids and Machinability Types of cutting tool wear mechanism 1. Abrasion wear 2. Adhesion wear 3. Diffusion wear 4. Chemical wear 5. Fatigue wear 6. Oxidation wear 7. Electrolyte wear Abrasion wear mechanism • If one of the surface contain very hard particles, then these particles will dislodge the material from the other surface during the process of sliding. AAA COLLEGE OF ENGINEERING & TECHNOLOGY Managed by Panjurajan – Amaravathy Trust and Promoted by Vinayaga- Sony Group of Industries Accredited by NBA (CSE, ECE, EEE & MECHANICAL), (Accredited by NAAC with “A” grade) (Approved by AICTE, New Delhi & Affiliated to Anna University, Chennai) (An ISO 21001: 2018 Certified Institution) Amathur, Sivakasi - 626 005. Department of Mechanical Engineering
- 2. Adhesion wear mechanism • Because of friction and plastic deformation high temperature is produced during the cutting process. It will cause welding action on tool surface by work material Diffusion wear mechanism • It was caused by the displacement of atoms due to high temperature at the tool-work-chip interface. Chemical wear mechanism • Chemical reaction occur between tool and workpiece in the presence of cutting fluid. • Due to this chemical reaction, the material was removed from the surface of tool due to erosion
- 3. Fatigue wear mechanism On microscopic level hill of tool will be eroded and fresh hill will be formed by interaction with the workpiece. This is known as fatigue type of wear mechanism. Oxidation wear mechanism At high temperature, oxidation rate is high, hence it will decrease the strength of a tool and finally it will create a wear at the cutting edge. Electrolyte wear mechanism It occurs due to galvanic action between tool and workpiece