US Synthetic Bearings Site


Grain Size

The properties of the PCD material can be manipulated by changing the size of the diamond powder before sintering. Surface finish of the wire and life of the die vary the most with changes in grain size. More

Carbide vs PCD vs SCD

Wire drawing dies are made of several materials including tungsten carbide, natural diamond, synthetic single crystal diamond, and polycrystalline diamond (PCD). Selection of a die often depends on the material being drawn and the desired surface finish of the wire.

Tungsten Carbide

Tungsten carbide is a good solution in a number of circumstances:

Polycrystalline Diamond

PCD is a matrix of diamond grains that are grown together using proprietary diamond presses. The interlocking grains provide extremely high abrasion resistance. Characteristics of PCD include:



PCD Materials Properties
DENSITY 3.90 g/cm3 Bertagnolli,
US Synthetic
COMPREHENSIVE
STRENGTH
6.9-7.6 GPa Roberts, Debeers
TENSILE
STRENGTH
1.3-1.6 GPa Cooley,
US Synthetic
YOUNG'S
MODULUS
841 GPa Roberts, Debeers
FRACTURE
TOUGHNESS
13-15 MPa√m Jiang Qian,
US Synthetic
HARDNESS
(Knoop)
49.8 GPa Debeers
COEFFICIENT of
LINEAR EXPANSION
1.3-3.9, 10-6/°C Glowka, SNL
COEFFICIENT of
FRICTION
0.05-0.08 Sexton, US Synthetic
THERMAL
CONDUCTIVITY
543 w/m-K Lin, UC Berkeley

Single Crystal Diamond

Single crystal diamond result in a superb surface finish on wire. Available both as natural diamond and synthetically grown diamond. Prices for large single crystal stones makes dies above .025 inches (0.63 mm) increasingly expensive. Good applications for single crystal dies are in very small diameters and high surface finish requirements.