3D Printed Tungsten Anti Scattering Grid has great potential in CT scanner

The application potential of 3D printing (additive manufacturing) tungsten anti scattering grid (ASG) in medical CT scanner is huge, not only because the high-density metal tungsten has strong absorption capacity for X-ray scattering, but also because the tungsten products manufactured with additive have the characteristics of strong stiffness, thin wall thickness, high density, more absorbed and scattered radiation and good shading.

CT scanner is one of the ways to diagnose New Coronavirus pneumonia. With the sudden impact of COVID-19 in 2020, the market demand for CT equipment increased significantly. As the key component of CT equipment, the usage of anti scatter grid also increased. The function of ASG is to absorb and filter the X-rays Scattered, refracted and overflowed from CT detection, so as to improve the quality of CT image.

ASG is generally made of pure tungsten because it has high requirements for strength, precision, shading, radiation absorption capacity, safety and structural stability. Tungsten is characterized by high melting point, high density, high strength, high thermal conductivity, high hardness, low thermal expansion coefficient and low sputtering erosion rate. Although its good mechanical, thermal and electrical properties make it widely used in medical, military, electronics, aerospace and other fields, it is also because of its high melting point and high hardness that tungsten machining is very difficult.

Generally speaking, from tungsten to the final product, it needs several deep processing technologies, such as forming, machining, bonding and surface treatment. However, in the processing process, tungsten products often appear deformation, crack, creep, stress fracture and so on, which will reduce their quality.

In order to solve the above problems, modern manufacturers say that tungsten anti scattering grids can be processed by selective laser melting process (SLM) in 3D printing technology. SLM technology selects laser as the energy source and scans the metal powder bed layer layer by layer according to the path planned in the three-dimensional CAD slice model. The scanned metal powder achieves the effect of metallurgical combination through melting and solidification, and finally obtains the metal parts designed by the model. It not only overcomes the problems brought by traditional technology in manufacturing metal parts with complex shapes, but also prepares metal parts with almost full density and good mechanical properties.

The research shows that the wall thickness of tungsten anti scattering grid of SLM technology can reach 0.08-0.1mm, the forming accuracy can be controlled at 0.02mm, and the density can be as high as 99%. Therefore, compared with the products manufactured by traditional technology, it is more suitable for CT scanners.

China Tungsten Online has more than 20 years of experience in R & D, producing Tungsten metal and alloy Anti Scattering Grid by traditional PM method and 3D printed. For more details, please visit our web site www.ctia.com.cn or contact us via sales@chinatungsten.com

 

Analysis of latest tungsten market in China from Chinatungsten Online

 

China’s domestic tungsten price edged lower in the week ended on Friday, August 27, 2021 after a surge since May. In addition, stated-owned companies and listed tungsten companied also reduced their long-term contract prices for the second half of August.

Xiamen Tungsten’s APT bid price was $299.5/mtu for the second half of August, down $3.6/mtu compared from the first half of this month. 

Zhangyuan Tungsten released its long-term contract prices for late August: black tungsten concentrate (WO3≥55%) price was $17,539.7/ton, down $158.7/ton; scheelite concentrate (WO3≥55%) price was $17,301.6/ton, down $158.7/ton; APT price was $301.3/mtu, down $1.8/mtu from the first half of this month. 

High grade black tungsten concentrate was quoted at $18,015.9/ton by Jiangxi Tungsten, unchanged from last time. 

Xianglu Tungsten quoted 55% black tungsten concentrate at $17,460.3/ton, down $238.1/ton; scheelite concentrate was quoted at $17,301.6/ton, down $238.1/ton; APT was quoted at $297.7/mtu, down $5.4/mtu from early August.

Thanks God, I.m here again after years!

It's realy a long time  I lost my account of my blogger "tungsten alloy". I'm nt sure how many poeple like me always lost accounts and codes in the net generration.

We have more and more SM to connect the world and our friends, family and cooperators now and more accounts with codes we have to remenber in more ways, or we may lost the world as we lost it.

I have been processing tungsten products for almost 30 years with much experiences but less technology of how to improving our web and search engine optimization. 

Hope to learn more about both of them and share our tungsten knowleges with you.

 

Factors of Selecting Radiation Shielding

The most common criteria for selecting shielding materials are radiation attenuation, ease of heat removal, resistance to radiation damage, economy and structural strength.

For the material, as we know, tungsten is always the suitable metal resistant to radiation damage, although there is some change in their mechanical properties after sintering.

Also the shielding cost is quite important; cost of tungsten must be a little expensive against the effect of shield size on other material, such as lead, for example, building size and support structure. However, its radiation absorption is excellent.

In that way to consider selecting a radiationshielding, then would be helpful to realize it varies with applications. The overall thickness of material is chosen to reduce radiation intensities outside the shield to levels well within prescribed limits for occupational exposure or for exposure of the general public. The reactor shield is usually considered to consist of two regions, the biological shield and the thermal shield. It is usually designed to absorb most of the energy of the escaping radiation and thus to protect the steel reactor vessel from radiation damage. It is often made of steel and is cooled by the primary coolant. The biological shield is added outside to reduce the external dose rate to a tolerable level.

Tungsten Radiation Shielding for X-rays

Major sources of radiation are nuclear reactors and associated facilities, medical and industrial x-ray and radioisotope facilities, charged-particle accelerators, and cosmic rays. Types of radiation are directly ionizing and indirectly ionizing, such as neutrons, gamma rays, and x-rays, etc. In most instances, protection of human life is the goal of radiation shielding. In other instances, protection may be required for structural materials which would otherwise be exposed to high-intensity radiation, or for radiation-sensitive materials such as photographic film and certain electronic components.

Gamma-ray and x-ray photons lose energy principally by some types of interactions: photoemission and pair production. Neutrons lose energy in shields by elastic or inelastic scattering. Elastic scattering is more effective with shield materials of low atomic mass, notably hydrogenous materials, but both processes are important, and an efficient neutron shield is made of materials of both high and low atomic mass.

Tungsten material could be used for radiation protection as its high density with excellent radiation absorption ability. For more details, you could visit tungsten radiation shielding for X-rays.

Tungsten Plastic for Radiation Shielding

Today, I received a sample of tungstenplastic for radiation shielding, which has the density about 10g/cm3 of a soft materiel could be shape various dimensions as per what you want.

It could be used as the radiation shielding clothing to shield the radiation such as X-ray, gamma ray, etc.

It has high shielding ability, environmental-friendly, flexibility for radiation shielding, compared to lead; tungsten plastic is lighter and thinner but with non-toxic and good radiation absorption ability. Also, if there is a need, it could be machined as it is soft enough to have a good machinability, so it could be used as clothing or be stuck onto the surface of the radiation room for radiation absorption. Different size will be available.

Also it could be used for medical imaging, radiotherapy systems, nuclear medicine, security systems, industrial CT, nuclear industry and other protective equipment for the operators.

High Specific Gravity Tungsten Alloys

High Specific Gravity Tungsten Alloys

 

 

Besides the traditional high specific gravity alloy. Such as: W-Ni-Fe, W-Ni-Cu series, W-Ni-Cu-Fe-Co series high gravity alloy was created by our newly research.. It’s elongation, tenacity, and processing properties much better than the traditional ones; density 16.5~18.8g/ cm³, hardness HRC25~30 and Elongation/Break≥10%.