The optimization of the powder metallurgy is crucial to the final performance of molybdenum-copper materials, which mainly affects the following aspects:
1. Density
Density is one of the key parameters that determine the properties of alloys. Increasing the density can effectively reduce the porosity of the material and improve its thermal conductivity and mechanical properties. Measures such as the use of ultra-fine powders, optimized sintering temperatures, and extended holding times can increase the density of the final material.
2. Thermal conductivity
High thermal conductivity is one of the important properties of molybdenum-copper alloys. Due to the large difference between the thermal conductivity of molybdenum and copper (about 138 W/m·K for molybdenum and 390 W/m·K for copper), the thermal conductivity of the material is mainly affected by the microstructure uniformity, porosity and sintering process. High thermal conductivity can be achieved through liquid-phase sintering and HIP pressing, which meets the heat dissipation needs of high-power electronic devices.
3. Mechanical properties
The mechanical strength of powder metallurgy molybdenum-copper alloys is generally lower than that of traditional cast or wrought metal materials, but by optimizing the sintering process, such as using liquid phase sintering and hot isostatic pressing, the tensile strength, impact resistance and wear resistance can be effectively improved, making them suitable for more demanding applications.
4. Coefficient of thermal expansion
The coefficient of thermal expansion (CTE) of molybdenum-copper materials is between that of pure molybdenum and pure copper, and can be optimized by adjusting the alloy composition to meet the matching needs of specific applications. For example, alloys with higher molybdenum content have a lower CTE and are suitable for electronic packaging materials that require high thermal expansion matching.
The powder metallurgy process is an important method for the preparation of molybdenum-copper alloys, which is widely used because of its strong controllability and large-scale production. By optimizing the powder mixing, molding, sintering and post-processing processes, the density, thermal conductivity and mechanical properties of the material can be significantly improved to meet the needs of different application scenarios. In the future, with the development of advanced sintering technologies (such as discharge plasma sintering and microwave sintering), the performance and manufacturing efficiency of molybdenum-copper alloys will be further improved, and they will play a greater role in high-end electronic packaging, aerospace devices and heat dissipation materials.
