Cutting-Tool Materials and Cutting Fluids

Cutting-tool are subjected to:

• high temperatures

• high contact stress

• rubbing along the tool–chip interface and along the machined surface

• wear resistance

The cutting-tool material must possess the following characteristics,EXCEPT...

• Chemical stability and inertness

• Wear resistance

• Toughness and impact strength

• Hot hardness

• high contact stress

Types of cuttng fluids:

• Oils

• Emulsions

• Semisynthetics

• Synthetics

• Water

Methods of Cutting-fluid Application in proper step is:

• Flooding-Mist-High Pressure System-Through the cutting tool system

• Mist-High Pressure System-Through the cutting tool system-Flooding

• Flooding-Through the cutting tool system-Mist-High Pressure System-

The two major groups of carbides used for machining are:

• tungsten carbide

• titanium carbide

• Cast-cobalt Alloys

Characteristics of cast cobalt alloys:

• good wear resistance

• can maintain their hardness at elevated temperatures

• not tough as high-speed steels

• high hardness over a wide range of temperatures

manufacturing these tools by using powder-metallurgy techniques such as:

• Functionally Graded Carbides

• Micrograin Carbides

• Tungsten Carbide

• Titanium Carbide

Coatings have unique properties, such as:

• Lower friction

• Higher adhesion

• Higher resistance to wear and cracking

• Higher hot hardness and impact resistance

• Acting as a diffusion barrier

Characteristics of Cubic boron nitride:

• small sizes without a substrate

• its chemically inert to iron and nickel at elevated temperatures

• Its resistance to oxidation is high

• it is particularly suitable for cutting hardened ferrous

• high wear resistance

diamond as a cutting tool has highly desireable properties such as:

• high wear resistance

• low friction

• it has ability to maintain a sharp cutting edge.

• low wear resistance