Please can you give a brief introduction and some examples of refractory metals?
Refractory metals have extremely high melting points, up to 3,500°C, and include tungsten, molybdenum, tantalum, and niobium.
They are characterized not only by high melting points, but also by being difficult to mine and work, requiring special techniques beyond conventional metallurgy.
H.C. Starck Solutions, with almost 100 years of experience in powder metallurgy, is one of the leading producers of these high-quality, -tech, and -performance metals.
Their unique properties make refractory metals all but indispensable in our modern world.
By developing and producing customized powder morphologies and high-precision mill products, and fabricated and machined components from the refractory metals tungsten, molybdenum, tantalum, and niobium, H.C. Starck Solutions makes a significant contribution to enabling cutting-edge developments in innovative high-tech industries.
When were refractory metals first used in a medical setting and how have their applications expanded over time?
It is not as much the expansion to new applications that has driven the demand for refractory metals in medical equipment as it is the increase in cancer detection.
Due to their unique properties, refractory metals can be used in a large variety of medical devices.
The largest area of application for Molybdenum and Tungsten is in the x-ray tubes and detectors used in diagnostic imaging, followed by the field of radiation therapy where tungsten products are used for shielding and beam collimation.
What properties of Tungsten make it suitable for use in radiation shielding?
The suitability of a material for radiation shielding is determined mainly by its density. Tungsten’s density of 19.3g/cm3, which is close to that of gold and 50% more dense than lead, make it the material of choice for most radiation shielding and collimation applications.
Compared to lead, tungsten is environmentally friendly and compliant to the Restriction of Hazardous Substances regulations (RoHS).
Moreover, its higher strength allows it to be machined to very close tolerances. This becomes essential for critical applications, such as for multi leaf collimators.
As a radiation shielding material in medical applications, tungsten is most commonly used in radiotherapy devices.
Tungsten shielding parts block radiation from locations where it is not wanted and tungsten collimators direct and shape the radiation beam.
This allows the most precise targeting of the cancerous tissue while shielding the healthy tissue and organs. Tungsten can also be used for isotope shielding.
Especially in the medical industry, shielding requirements become more and more challenging. Medical equipment engineers strive towards reducing the radiation dose, patient exposure time and damage to healthy tissue.
In order to achieve these targets they continually develop and redesign their devices and depend on highest quality materials. H.C. Starck Solutions' tungsten products can be custom machined to fit the most precise designs and demanding property requirements.
How does Molybdenum differ from Tungsten and what oncology applications is it used for?
The primary use for refractory metals in oncology applications is for radiation shielding or collimation of the beam.
With a density of only 10.3g/cm3, molybdenum is much less used in shielding applications than tungsten. However, molybdenum offers higher thermal conductivity and lower thermal expansion coefficient.
This makes it an optimal material for use in rotating x-ray anodes and bearing parts, which are part of the x-ray tubes in CT imaging systems.
Thus, diagnostic imaging, rather than oncology, is molybdenum’s key application area. However, many of the newest generations of radiation therapy systems include the CT scanner in the same piece of equipment.
H.C. Stark Solutions provides several different advanced refractory metal products that can be used in cancer treatment. How do H.C. Starck Solutions’ products differ from others on the market?
H.C. Starck Solutions is the largest manufacturer of tungsten alloys that is fully backward integrated from the mine to machined part.
Our tungsten joint-venture in China gives our fabricated parts production facility access to in-house produced raw materials with the same high quality that H.C. Starck Solutions’ powders are known for. Additionally, our mining joint-venture in Vietnam secures long-term raw material supply security.
H.C. Starck Solutions offers a global market presence with production sites in all major regions of the world. Each location’s unique capabilities and expertise are used to create Center’s of Excellence as a part of H.C. Starck Solutions’ continuous improvement effort to service their customers.
Not only their proximity to customers, but also their end-markets results in the highest degree of flexibility and support.
With regards to our products, our high-end engineering capabilities and in-depth experience provide customized solutions for the individual needs and challenging requirements of our medical customers.
What do you think the future holds with regards to the use of refractory metals in cancer treatments?
Today, North America and Europe are much more advanced, mature markets in terms of radiotherapy equipment installed. The future use of refractory metals in cancer treatment will be mainly driven by other nations starting to use radiation therapy to treat cancer.
The treatment devices may become more diverse and new equipment generations will become more powerful, faster and precise, which will challenge the development of higher precision with competitive cost.
Additional government regulations relating to the use of lead-based products may increase in the demand of materials with high densities that are compliant with these regulations.
What are H.C. Starck Solutions’ plans for the future?
H.C. Starck Solutions is continuing to advance the precision capabilities of the use of refractory metals used in medical products and has been expanding its worldwide facilities.
Continual R&D investments into next generation fabrication technologies such as 3D Printing and Tape Casting of these refractory metal products will expand the use to designs and applications in medical devices.
About H.C. Starck Solutions
The H.C. Starck Group is a leading global supplier of technology metals and advanced ceramics. The company operates modern manufacturing facilities in Europe, America, and Asia and serves growing industries such as the electronics, chemicals, automotive, medical technology, aerospace, energy technology, and environmental technology industries, as well as engineering companies and tool manufacturers.
On December 31, 2017, the H.C. Starck Group had 2,600 employees in the United States, Canada, Great Britain, Germany, China, Japan, and Thailand.
H.C. Starck’s products are predominantly based on technology metals: Tantalum, Niobium, Tungsten, and Molybdenum.
The Fabricated Products Division converts technology metal powders into customized semi-finished and finished products through pressing, sintering, rolling, melting and thermo-mechanical processing and surface treatment.
The Tungsten Division provides high performance products for the mechanical engineering and tool making, automotive and energy industry, aviation industry, and the chemical industry, for example:
- tungsten carbides for carbide tools and wear parts
- tungsten and cast tungsten carbides for oil and gas drilling
- tungsten metal powders for heavy metal alloys
- tungsten chemicals as precursors for catalysts
The Advanced Ceramic Components (CER) Division manufactures specialized technical ceramic parts and films. CER produces engineering parts such as sealing rings, functional parts including fuel cells for solid oxide fuel cell (SOFC) systems and products for dental applications as well as for armor and wear protection. Furthermore, CER focuses on technological developments to expand the portfolio toward product applications in the semiconductor industry.
In 2018 H.C. Starck sold the division Surface Technology & Ceramic Powders to the Swedish Höganäs Group, effective March 1st and the division Tantalum and Niobium to the JX Nippon Mining & Metals Group, effective July 1st.
The group is led by a two-member Executive Board: Dr. Jens Knöll (Chairman of the Executive Board), Dr. Jan Lösch (Member of the Executive Board).
H.C. Starck was founded in Berlin in 1920. Since 2007, the company is owned by financial investors Advent International and The Carlyle Group.
H.C. Starck is registered in Goslar (Germany) and the Group’s headquarters is located in Munich (Germany).