chronological developments in cutting tool materials

Chronological development of cutting tool materials

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MMW = NR(HE)

where,MMW- men’s material welfareNR- natural resources availableHE- Human Efforts

TOOLS


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CHRONOLOGICALDEVELOPMENT OF

CUTTING TOOLMATERIALS

Presented by:

Bilal Hasan [email protected]

March, 2013


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Basic Requirements of Tool Material• Hardness: retaining hardness at

elevated temperatures• Toughness: to survive under

intermittent cutting operation• Wear resistance: attainment of

acceptable tool life before replacement• Thermal Conductivity, etc.


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Chronicle of tool materials


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Chronicle of tool materials


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Ancient ToolsStone Use predominated over millions of years. Used to make hand axes, knives and arrow heads. limitation - inability to produce different shapes.

Copper and Bronze Use started as early as between 5000-6000 b.c. Copper used mostly for knives and chisel. Use of bronze started between 3000-3500 b.c. Bronze - axes and hatchets, knives, arrowheads, lance heads

and swords

Iron Use dates back to 1200 b.c. Early applications - swords, knives, chisels, axes, sickles and

arrow heads.


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Stone Tools


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HIGH CARBON STEEL Carbon percentage -0.8 to 1.5% Oldest known tool material Low Hot Hardness Maximum Cutting Speed – 5-7 m/min Maximum Temperature Limit -250 ºC Suitable for Low Cutting Low Cost Used for taps, dies, hacksaw blades,

hand drills, wood working tools etc.

(Industrial Rev. Period)


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Self Hardening Steel

• No need of water quenching• Speed for steel 7-10 m/min• Self hardening because of Mn and Cr• Increased temp limit because of W

W Mn Cr C

(6-10)% (1.2-2)% 0.5% (1.2-1.5)%

(1868)Robert Mushet


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HIGH SPEED STEEL

Cutting speed up to 30 m/min Maximum Limiting Temperature (560-

650)ºC Less Costly Excellent toughness Widely used in industries as a solid Tool

like form tool, drill, milling cutters, endmill, reamers, Broach, Single point cutting tool etc.

T-Series (Tungsten Type) M-Series (Molybdenum type)

W Cr Va C W M Cr Va

18 4 1 0.75 6 6 4 2

(1906)Taylor & White


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CAST COBALT ALLOYS

Manufacturing Process- Casting Hot hardness- 760ºC Cutting Speed -45 m/min Higher tool life compare to H.S.S. Hardness -58 to 64 HRC Lower toughness/brittle Limited strength Used for form tool, Machining cast and

malleable iron.

Co Cr W C

48-53% 30-33% 10-20% 1.5-2.0%

(1915)Elwood Haynes


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CEMENTED CARBIDES

Manufactured by Powder Metallurgy Grain size – 1 micron to 8 micron

Many verity can be produced by controlling grain size and % of cobalt.

W C Co

94% 6% 3-12%

Drawback is itsAffinity with

steel

Tunsten Carbide(1920)

Henry Moisson


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Tungsten-Titanium-Tantalum Carbide BondedWith Cobalt ({WC+ TiC + TaC} -Co)

High hardness and wear resistance Maximum limiting Temperature -1200

ºC Various Shapes Of Inserts Cutting Speed -100 m/min High Tool life High compressive strength High production rate Better surface finish

W TiC TaC Co

15% 10%


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Coated Carbides Coating of micro thin layer insets made of tungsten carbide Most commonly used coating materials are:

Titanium Nitride (TiN) Titanium Carbide (TiC) Titanium CarboNitiride (TiCN) Aluminium Oxide (Al2O3) Zicronium Nitride (ZrN) Titanium Aluminium Nitride (TiAlN)

Methods of Coatings

Chemical Vapor Deposition (CVD) Physical Vapor Deposition (PVD)

Advantages:

High hot hardness Chemically stable High cutting speed -150 to 250 m/min High Tool life (2 to 3 times higher than carbide)


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SUPER COATED CARBIDES

WC- Higher interior Hardness and toughness

Triple layer coating Inner layer –FCCN (Fibrous Crystalline

Carbon Titanium ) Balance between wear resistance and

fracture resistance Outer coating –Al2O3 (Fine Grain) outer most layer – Special laminated

Titanium Alloys Superior high temperature strength.

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Alumina Tools (Ceramics)

High abrasive of wear Resistance

Less tendency to weld to metal

Very high compressive strength

Very high hot hardness High refractoriness – 1800 ºC High Cutting Speed -200 to

400 m/min Longer tool life Used for cutting steel and HSS Used for high speed

machining

Al2O3 + MgO Cr2O3, SiC, TiO, TiC

90% 10%

Limitation

Poor Toughness Unreliable (Sudden fail) High rigidity of set up


(1960s)


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Cermets

70% aluminum oxide & 30 % titanium carbide

Cermets contain molybdenum carbide, niobium carbide and tantalum carbide.


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SIALON• Silicon Nitride based alloy with Aluminium

& Oxygen addition• Low Coefficient of thermal expansion• Increased resistance of thermal shocks &

thermal fatigue• Used with Negative rake• Speed for C.I. is 600 m/min• Speed for steel is 60m/min• Hot pressing and sintering of mixture of

Al2O3 and Si3N4 powder

(1976)


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CUBIC BORON NITRIDE Sanitized artificially made under high pressure and

high temperature. Stable up to 10000C temperature. Manufactures under ultra high pressure and high

temperature. Excellent in chemical and thermal stability. Hardness next to natural diamond.

Applications:

Permits high feeds and speeds. Available in large variety of shapes and sizes in

insert form. Use to turn bore, face, groove and mill difficult to

machine materials.


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DIAMOND Hardest substance BHN 7000 High heat conductivity (Twice then steel) High hot hardness 1650 ºC High wear resistance Very low co-efficient of friction High compressive strength High cutting speed (300 to 1000 m/min) High tool life Used for cutting hard material like glass,

plastic, Ceramics and cemented carbides. Used for turning and dressing wheel of

grinding wheel Used for machining non-metallic and non-

ferrous alloy


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Polycrystalline Diamond ( PCD ) Synthetic having diamond matrix structure. Sintered under extremely high temperature

and pressure. High in uniform hardness and abrasive

resistance in all direction. Very high tool life compare to carbide tool

(50 times). Shock resistance is more than natural

diamond. Consistency in wear resistance. Available in large verity of shapes and sizes. Discs as large as 58 mm in diameter. Better thermal conductivity then natural

diamond. Lower cost then natural diamond. Used for machining milling, turning,

grooving, facing and boring.


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Diamond coated carbide tools Use of Polycrystalline diamond as a coating Difficult to adhere diamond film to

substrate Thin-film diamond coated inserts now

commercially available Thin films deposited on substrate with PVD

& CVD techniques Thick films obtained by growing large

sheet of pure diamond Diamond coated tools particularly effective

in machining non-ferrous and abrasive materials


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FUTURE…Few possible concepts –• Thermo mechanical treatment to

produce textural or orientation hardening

• Application of splat cooling technique to produce material of very fine grain size approaching an amorphous structure

• Continued and composite concepts

chronological developments in cutting tool materials

Technology

form tool

solid tool

tool materials16

tool materials7

tool materials13

tool materials4

tool materials5

tool materials14