Marketech International is a global supplier of Tungsten and Tungsten Alloys. We also specialize in the machining of tungsten products for a variety of industry applications. With over 25 years of specialty materials experience, we supply only the highest quality materials and can provide the technical expertise to help you select the most suitable product for your particular needs.

ABOUT TUNGSTEN

Tungsten, also referred to as Wolfram, is a chemical element with the chemical symbol W and atomic number 74. After Carbon, Tungsten has the highest melting point of all elements. Tungsten is among the heaviest metals found on Earth. It has excellent high temperature mechanical properties, with the lowest expansion coefficient and highest conductivity of all metals.

Properties of Pure Tungsten

TUNGSTEN APPLICATIONS

Tungsten can be used in hard metal applications, but is also commonly used as an important component of alloys and steel. Tungsten alloys are a preferred choice for applications where high density, high thermal conductivity, and low thermal expansion are important considerations. As pure tungsten itself is extremely brittle and difficult to machine, tungsten alloys can provide the beneficial properties of pure tungsten while allowing for increased flexibility in producing final components.

Examples of Tungsten Applications

TUNGSTEN AND TUNGSTEN ALLOY PRODUCTS

Marketech International supplies Tungsten and Tungsten Alloys such as copper, iron, nickel and silver in a variety of forms:

• Plate and Sheet
• Rod and Wire
• Tubes
• Tungsten Carbide
• Heavy Alloy
• Electrodes and Crucibles
• Tungsten Powder
• Special Shape Products
• Custom Machined Components

TUNGSTEN PRODUCT SPECIFICATIONS

* values are approximated and may vary

MACHINING SERVICES

Marketech International is a leader in high-speed, ultra precision machining. We specialize in machining tungsten and other refractory metals for use in a variety of industry applications. Our facility is equipped with the technology and machinery to produce complex components and assemblies. Our staff at Marketech has the experience and knowledge to accommodate specifications for machining many advanced materials. We are globally recognized for our high quality parts, reasonable pricing, and superior customer service.

TECHNICAL DATA FOR MACHINING TUNGSTEN

Forming and Stamping

Tungsten can be fabricated into many simple shapes and configurations. It can be folded, bent, formed, spun, flow-turned, sheared, stamped, punched, and riveted. On the other hand, tungsten is a strong, hard, crack-sensitive metal that is usually brittle at room temperature. It requires special handling and skill beyond that necessary for most metals and alloys.

The most important rule to remember when working with tungsten is that it must be formed or cut at temperatures well above its transition temperature. Failure to follow this rule will generally result in cracked or laminated parts. Care should be taken to insure that the metal remains at this temperature throughout the entire forming process. The use of cold tooling which rapidly chills the metal can be as harmful as not preheating the material.

The following Basic Rules apply to almost all fabricating techniques:

1. Tungsten should be fabricated well above its transition temperature.
2. Tungsten must not be heated above its recrystallization temperature unless the resulting brittle structure is of no consequence.
3. Tungsten is a notch sensitive material. The elimination of all stress-risers prior to fabrication is always a good practice.
4. Tungsten has directional properties that relate to the rolling direction. Whenever possible, bends should be made perpendicular to the rolling direction of the sheet.
5. Cutting edges should always be kept sharp, and clearances should be kept as small as possible.
6. Bending radii should be as generous as possible.

Joining

Joining tungsten to itself or to other metals should be undertaken with caution and an understanding of the limitations involved. Tungsten can be welded to itself. However, the resulting weldment is always recrystallized and hence brittle. Even the use of a W/Re filler rod does not eliminate the brittleness of the metal adjacent to the heat-affected zone. On the other hand, if a leak-tight high temperature joint is required, welding is the only solution.

For joints that do not have to be leak-tight but require good high temperature mechanical strength, the use of either tungsten or tantalum rivets has proven quite satisfactory. Tantalum rivets, while not as strong as tungsten rivets, are much easier to head. Tungsten rivets take more skill to head, but are the most satisfactory.

Machining and Grinding

Tungsten can be machined by turning, milling, or drilling. For thick-walled parts, slight preheating of the work to 400 °F is sometimes helpful; otherwise highly chlorinated oil such as trichloroethylene is used. Using a C-2 Type Carbide Tool, a suggested Geometry is:

• Side Angel: 10°
• End Cutting Edge Angle: 3° to 10°
• Back Rake: 0°
• Clearance: 3° to 5°
• Nose Radius: 1/32" to 1/16" Radius
• Cutting Speed: 100 to 200 RPM

The final shaping of tungsten parts is frequently done by grinding. Silicon carbide wheels with a hardness of J to L and a grain size of 100 to 120 have proven useful for most applications. Since tungsten is hard and brittle, surface checking can be a problem unless adequate cooling is used. An oil emulsion type coolant is recommended.

Marketech International has developed long-term strategic global partnerships. We bring our customers the highest quality products at the lowest cost and have resources to offer non-standard materials.