High-power X-ray tubes use tungsten-rhenium-molybdenum composite rotating anode targets
The X-ray tube is the core component of all X-ray instruments. The performance of X-ray equipment largely depends on the quality of the X-ray tube. Among X-ray tubes, the anode target is a crucial component, as it directly affects the emission intensity of X-rays and the lifespan of the tube. Therefore, developing high-performance anode target materials is the key to improving the technical level of X-ray detection.
With the development of X-ray detection technology, large heat capacity and strong X-ray output rotating target-type X-ray tubes are widely used in the medical diagnosis field to meet the requirements of continuous load or instantaneous high load input. When modern high-power X-ray tubes are operating, the high voltage applied to the filament to emit electrons can reach 200KV. High-speed electrons hitting the anode target surface generate strong X-rays, but only about 1% of the electrical energy is converted into X-ray energy, while the remaining 99% is converted into heat and accumulated on the target, causing the local temperature of the focus track to exceed 2600℃ and the target body temperature to reach above 1300℃. This places extremely high requirements on the high-temperature resistance and thermal shock tolerance of the target material.
Tungsten is used as a target material due to its high melting point, excellent high-temperature strength, good heat dissipation performance, and high atomic number. It can generate strong X-rays when bombarded by an electron beam. However, X-ray tubes operate intermittently, and the target surface is prone to cracking under repeated thermal cycling. Tungsten has a notch sensitivity effect. Once a crack occurs, it can rapidly expand, deepen, and even detach from the substrate, causing damage to the X-ray tube. Therefore, pure tungsten target materials have significant limitations in practical applications.
To overcome the shortcomings of pure tungsten target materials, researchers added a small amount of rhenium or other high-melting-point and high-atomic-number transition element to tungsten to form tungsten alloy target surfaces. Compared with pure tungsten target surfaces, tungsten-rhenium alloy target surfaces have more excellent anti-welding damage performance, can effectively prevent cracking, ensure clear imaging, and significantly increase the service life of X-ray tubes. This makes tungsten-rhenium alloy an ideal material for high-performance rotating anode target surfaces.
If a pure tungsten target is used, due to the high density of tungsten, when the diameter of the target is increased to enhance its heat capacity, the weight of the target significantly increases. During high-speed rotation, the torque required for starting increases, the starting time prolongs, and the load on the excitation coil and bearings also increases, which is extremely unfavorable for the operation of the X-ray tube. At the same time, once the notch sensitivity effect of tungsten is triggered and cracks occur, the entire target will be destroyed. Therefore, a material that can be well combined with tungsten, can reduce weight, and can increase heat capacity is needed as the base material.
The density of molybdenum is approximately half that of tungsten, and its specific heat is more than twice that of tungsten. Moreover, it has high temperature strength and can be firmly combined with tungsten to form a whole. Therefore, molybdenum is widely used as the base material for rotating anode targets. Under the same diameter conditions, the molybdenum-based tungsten target weighs about half less than pure tungsten target; while under the same weight conditions, the thermal capacity of the molybdenum-based tungsten target increases by more than twice, thereby significantly increasing the output power of the target. The tungsten-rhenium-molybdenum alloy rotating anode target material, with its excellent comprehensive performance, has become the core choice for modern high-power X-ray tubes.
Tungsten Target are demanded in various parts of the world, such as: USA, Canada, Chile, Brazil, Argentina, Colombia, Germany, France, United Kingdom, Italy, Sweden, Austria, Netherlands, Belgium, Switzerland, Spain, Czech Republic, Poland.
As professional Chinese manufacturer, Mosten Alloy can produce and supply tungsten electrode, tungsten sheet, tungsten foil & strip, tungsten block, tungsten tube, tungsten rod, tungsten wire, tungsten processing workpiece according to customer demand.
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