J & M Diamond Tool: PCD and CBN Information

J&M Diamond Tool, Inc.

Composition of PCD and CBN

Composition of PCD (Polycrystalline Diamond)	Composition of CBN (Cubic Boron Nitride)
Materials recommended for cutting with PCD	Materials recommended for cutting with CBN
Recommended Speeds and Feeds of PCD	Recommended Speeds and Feeds of CBN
Use and Care of Diamond Tools

Composition of PCD (Polycrystalline Diamond)

Polycrystalline Diamond (PCD) is a synthetic diamond product that is produced by sintering together selected diamond particles with a metal matrix using sophisticated technology. The diamond and matrix, when sintered together under high temperatures and pressures, creates a PCD tool blank that is high in uniform hardness and is abrasive resistant in all directions. This PCD diamond layer is then bonded to a tungsten carbide substrate, which provides strength and a brazable base to permit bonding to other metals.

Polycrystalline tipped tools are exceptionally resistant to wear compared to tungsten carbide or ceramic tools. In certain applications, PCD tool life can exceed carbide cutting tool life 50 to 100 times.

In certain applications, polycrystalline tipped tools have several advantages over natural diamond.

Shock Resistance

PCD is more shock resistant over natural diamond because of its random orientation structure of the diamond particles, and is backed by a carbide substrate.

Consistency

PCD is more constant in wear. Again because of the random orientation of diamond particles. Natural diamond is a single crystal in nature and has soft and hard grains. Depending on the shape of the natural diamonds and the tool being manufactured, it is sometimes not practical to have the hardest grain on the cutting edge.

Availability

PCD is readily available in a large variety of shapes and sizes. Discs as large as 60 mm in diameter are now available. Natural diamond is limited to what is formed in nature. Diamond, even with only an 8 mm long cutting edge is extremely difficult to find and is very costly.

Flexibility

PCD is a conductor. This allows us to routinely produce complex form tools and grooving tools with our wire EDM machines. Such tools are impossible to produce in natural diamond.

Cost

PCD blank costs are considerably lower than the cost of natural diamond stones, and the availability of different shape PCD blanks reduce manufacturing cost significantly. The longer of a cutting edge required, the larger the savings of PCD over natural diamond due to the rarity of larger stones.

Natural diamond and PCD diamond compliment each other. Natural diamond is denser than its PCD counterpart and consequently can be polished to a keener cutting edge.

Natural diamond is best suited to produce very fine finishes and precise tolerances as required in the manufacturing of jewelry, plastic contact lens, computer memory discs, and aluminum camera parts. See natural diamond tools.

Polycrystalline diamond tooling can be used in a wide range of machining operations such as milling, grooving, turning, facing and boring. They are recommended for machining nonferrous metals and abrasive non metallics.

Recommended Speeds and Feeds of PCD

Materials recommended for cutting
with PCD

Aluminum and aluminum alloys
Copper, brass and bronze alloys
Zinc and magnesium alloys
Gold and silver Tungsten carbide, pre sintered and sintered
Carbon and graphite Ceramics, unfired
Epoxy resins
Plastics and rubber
Fiberglass composites
Graphite composites
Phenolics Chipboard and fiberboard

-
PCD cutting tools are available in various grades,
depending on the application.

PCD Material	Speed (SFM)	Feed Rate (IPR)	Depth of Cut (INCH)
Aluminum	3000-5000	005-.008	.005- .020
Aluminum (5-8% SI)	4000-6000	.010-.020	.005-020
Aluminum (8-12% SI)	3000-5000	.005.015	.005-020
Aluminum (14-18% SI)	1000-3000	.002010	.003.015
Copper	750-1500	.003-008	.005-.020
Bronze	1000-1250	.003-.008	.005-.020
Brass	2000-4000	003-.010	.005-020
Babbit	800-1200	.003-010	.005-020
Carbon	500-1000	.005- .015	.005- .030
Glass Fiber	750-1000	.001 -.010	.001-002
Carbon Composites	500-2000	.005- .015	.0 10-.100
Sintered Carbide	30-50	.004- .006	0005-.005
High Aluminum Ceramics	1200-2400	.001-.004	.0005-005
Wood and Composites	8000-13000	.010-100	010-.100

Top

Composition of CBN (Cubic Boron Nitride)

Cubic boron nitride (CBN) is an artificially synthesized material exceeded in hardness only by diamond. Unlike diamond, however, CBN is stable under conditions of high temperature (up to 1000°C) normally seen when machining hardened ferrous or super alloy materials.

Like polycrystalline diamond, CBN is available in a large variety of shapes and sizes. Discs are available up to 602 mm diameter. CBN is also available in several different grades, depending on the application.

CBN tools permit metal cutting at feeds and speeds much higher than conventional cutting tools materials. CBN tools are also being used to turn, bore and face hard materials, which previously could be formed only by grinding. Because CBN tools maintain a sharp cutting edge, part surface finishes are excellent, close tolerances are easy to maintain, and dramatic productivity increases can be expected.

Recommended Speeds and Feeds of CBN

Materials recommended for cutting
with CBN:

Alloy steels (45-68 RC)
Carbon tool steels (45-68 RC)
Die steel (45-68 RC)
High speed steel (45-68 RC)
Chilled cast iron
Ni Hard
Forged steel
Meehanite iron
Moly chrome steel rolls
Inconel 600
Rene
Incoloy
Monel
Stellite
Colmonoy
Waspoloy

C B N Material	Speed (SFM)	Feed Rate (IPR)	Depth of Cut (INCH)
Carbon Steel	200-500	.008 MAX	.020 MAX.
Bearing Steel	200-500	.008 MAX.	.020 MAX.
Alloy Steel	200-500	.008 MAX	020 MAX.
Die Steel	160-350	.008 MAX.	.020 MAX.
Tool Steel	160-350	.008 MAX.	.020 MAX.
High Tensile Cast Iron	200-500	.060 MAX.	.100 MAX.
Chilled Cast Iron	130-260	.032 MAX.	.100 MAX.
Grey Cast Iron	1000-2600	.020 MAX.	.040 MAX.
Powdered Metal	500-650	.016 MAX.	.120 MAX.
lnconel	500-650	.006 MAX.	.125 MAX.
Rene 41	500-650	.006 MAX.	.125 MAX.
Rene77	450-550	.006 MAX.	.015 MAX.
Incoloy	750~900	.006 MAX.	.125 MAX.
Monel	550-650	.006 MAX.	.125 MAX.
Stellite	550 -650	.006 MAX.	.125 MAX.
Colmonoy	550-650	.003 MAX.	.125 MAX.
Waspoloy	550-650	.003 MAX.	.060 MAX.

Use and Care of Cutting Tools

Diamond cutting tools are easily damaged, so the cutting edges should be covered with rubber or plastic caps when they are not in use. Store them in separate containers when they are not in your machine.

When inspecting and setting up, use optical instruments if possible. Use copper shimstock or plastic between the cutting tool and micrometers or height gauges, if these are used, to avoid breaking the cutting edge. Don't bring the diamond into contact with the work in a stationary position or stop the machine during the cut.

High speed reduces cutting edge pressure; low speed increases it, causing diamonds to break down more rapidly.

Vibration also shortens tool life, so machine tools should be in good condition.

J & M DIAMOND TOOL, INC.
Toll Free ( 800 ) 777-6813 - - Fax ( 401 ) 431-2222	Email: Information@diamondtool.com

| Terms and Conditions | Dealer and Distribution Inquires Welcome | Survey |