Excellent High-Temperature Performance:Ta10W alloy has a melting point of approximately 3000°C (pure tantalum melting point 2996°C, tungsten melting point 3410°C), maintaining excellent creep resistance and structural stability even at high temperatures. Its wire can be used long-term in oxidizing or inert environments above 1600°C, suitable for applications such as aerospace engine nozzles and high-temperature sensors.
Outstanding Corrosion Resistance: Tantalum-based alloys exhibit extremely strong resistance to acids, alkalis, and molten metals. Ta10W wire is stable in concentrated hydrochloric acid, nitric acid, and aqua regia, and its corrosion resistance in high-temperature molten salts (such as nuclear reactor cooling media) is significantly better than stainless steel or nickel-based alloys.
Excellent Mechanical Properties: Strength: The addition of tungsten significantly enhances the strength of tantalum, achieving a tensile strength of 800-1000 MPa at room temperature and retaining approximately 200-300 MPa at high temperatures (e.g., 1200°C). Tantalum's plasticity allows for grain refinement through plastic processing (such as drawing), resulting in wire elongation of 15%-25%, combining high strength with machinability. Its high density (approximately 16.6 g/cm³) provides excellent X-ray and gamma-ray shielding capabilities, along with its bioinertness, making it suitable for implantable medical devices (such as radioactive particle scaffolds).
The powder metallurgy process involves mixing tantalum powder and tungsten powder in a specific ratio → cold isostatic pressing → vacuum sintering (2000-2200°C) → forming a dense billet. This process allows for precise composition control but is costly. Plastic processing involves multiple hot rolling passes (1200-1500°C) to create a blank → drawing into wire (intermediate annealing is required to eliminate work hardening). The final wire diameter can reach 0.1-5 mm, and the surface requires electrolytic polishing or coating to improve oxidation resistance. Impurities such as oxygen and carbon significantly reduce plasticity and require purification through electron beam melting or arc melting to ensure impurity content is below 50 ppm.
Tungsten possesses excellent properties such as high melting point, high strength, and good oxidation resistance, and has been widely used in fields such as biology, electronics, and nuclear fusion. Furthermore, given its excellent radiation shielding properties against heat and plasma flux, it is considered a key strategic material for plasma-oriented components (PFCs) in future nuclear fusion devices. With the increasing demands for material forming in future manufacturing industries, various fields are increasingly requiring tungsten and its alloys to have complex structures. Currently, industrial-scale tungsten components are typically manufactured using powder metallurgy. However, the inherent hardness and brittleness of tungsten makes it difficult to process structural parts with small dimensions and complex shapes using powder metallurgy, thus limiting its applications. Laser powder bed melting (LPBF), also known as selective laser melting (SLM), is an important metal additive manufacturing (AM) technology. It is a bottom-up rapid prototyping technology for metal powder based on a three-dimensional model. Using a laser, metal powder is completely melted and solidified, forming a nearly fully densified metal part according to a pre-defined structure. It is a non-equilibrium, continuous solidification process involving micro-molten pools.
To further analyze the effect of tantalum carbide on cracks, this paper compares a tungsten-tantalum carbide sample with better formability and fewer pore defects with a pure tungsten sample (400 W, 300 mm/s). The mesoscopic crack morphology comparison between the two is shown in Figure 4. From the top and side surfaces, it can be seen that the crack density of the sample with the addition of tantalum carbide is reduced to a certain extent compared to pure tungsten. It can be observed that the grain size is significantly refined after the addition of tantalum carbide, and a large number of small-angle interfaces are formed. No obvious texture is found in the microstructure of either tungsten or tungsten-tantalum carbide. To accurately characterize the crack morphology at the microscale, the microcrack characteristics of pure tungsten and tungsten-tantalum carbide at the submicron scale are compared under a high-magnification electron microscope. As can be seen, the cracks in pure tungsten mainly propagated along the grain boundaries. Numerous nanopores were observed at the submicron scale; these nanopores propagated along the grain boundaries and developed into microcracks.
