MEC 322 Lecture Notes - Lecture 9: Titanium Nitride, Relative Velocity, Tool Steel

• School: Ryerson University
• Department: Mechanical Engineering
• Course: MEC 322
• Professor: Krishnan Venkatakrishnan

Document Summary

High hardness (hot hardness=less hard: need material harder than stock material, higher better wear characteristics (lasts longer, very high. Made with hard steel and soft iron body. Fracture failure: cutting force becomes excessive and/or dynamic leading to brittle fracture, often occurs in interrupted cuts/when inclusions in the work piece are encountered, premature failure. Temperature failure: high temperatures lead to plastic deformation, premature failure. Gradual wear: gradual wearing of the cutting tool, preferred: leads to the longest possible use of too, occurs. Crater wear: occurs on top rake face. Flank wear: occurs on flank (side of tool: wear modes: Abrasion: dominant cause of flank wear, mechanical wearing action due to hard particles (can"t avoid) Adhesion: high pressure localized fusion and rupturing. Chemical reaction: oxidization (oxide layer softer than the parent tool layer) (needs heat to occur, which you have) Not nitrogen or carbon because they are hard to react with.