The three most prominent physical properties of tungsten beads are high hardness, high density, and high melting point. High hardness provides excellent wear resistance, making them ideal materials for grinding and cutting. High density gives them significant advantages in weighting and balancing applications. A high melting point allows tungsten beads to withstand extreme high-temperature environments.
I. Basic Properties of Tungsten Beads
Tungsten beads typically refer to cemented carbide (WC) spheres with cobalt (Co) or other metals as binders, or high-density alloy spheres with tungsten (W) as the matrix. They appear as black hexagonal crystals with a metallic luster. High density is their core characteristic; cemented carbide beads generally have a density greater than or equal to 14.0 g/cm3, while high-density tungsten alloy beads have an even higher density, typically ranging from 16.5 to 18.75 g/cm3.
II. Mechanical Properties of Tungsten Beads
Tungsten beads possess extremely high hardness, a key characteristic for their wear-resistant properties. Their Mohs hardness is approximately 9.5, approaching that of diamond. Their microhardness (Vickers hardness) is typically >1500 kg/mm2. They exhibit high compressive strength; a 2mm diameter tungsten bead can reach 220 kgf. Their elastic modulus is high, exceeding 710 GPa, indicating exceptional rigidity and strong resistance to deformation. High-density tungsten alloys can achieve tensile strengths of 700-1000 MPa.
III. Thermal Properties of Tungsten Beads
Hard alloy beads have a very high melting point, approximately 2870°C. They have a low coefficient of thermal expansion, only about 1/2 to 1/3 that of ordinary iron or steel, resulting in good thermal stability. They also have low thermal conductivity, making them excellent heat conductors. High-density tungsten alloy beads have a very high thermal conductivity, up to five times that of mold steel.
IV. Electrical Properties of Tungsten Beads
Both hard alloy beads and high-density tungsten alloy beads possess good electrical conductivity.
