How do laboratory instrument die castings and molds achieve complex, thin-walled structures?
Publish Time: 2025-08-28
In modern high-precision laboratory instruments, such as spectrometers, chromatographs, refractometers, and rangefinders, structural components not only require excellent mechanical strength and dimensional stability, but also often require highly complex geometries and extremely thin wall thicknesses. These precision components are often manufactured using die casting, and laboratory instrument die castings and molds are particularly popular due to their ability to efficiently form complex, thin-walled structures.1. High-Pressure Die Casting is the Foundation of MoldingThe core of the die casting process lies in "high pressure" and "high speed." Under high pressure (typically tens to hundreds of MPa), molten metal is rapidly injected into a precision mold cavity, where it solidifies and forms under pressure. This high filling speed and high holding pressure enable the molten metal to fully fill even the finest corners and thin-walled areas in the mold, enabling complete molding even with wall thicknesses as low as 0.8–1.5 mm. Compared to traditional casting or machining, die casting offers unparalleled advantages in the integrated molding of complex structures, reducing subsequent splicing and assembly errors and improving the rigidity and stability of the instrument's overall structure.2. High-precision mold design and manufacturing are keyThe realization of complex, thin-walled structures relies heavily on the design and manufacturing of precision molds. Modern die-casting molds utilize integrated CAD/CAE design. Using simulation software, metal flow, temperature distribution, solidification processes, and stress and deformation are predicted, optimizing gate location, runner systems, and cooling channel layout to avoid defects such as cold shuts, undercasting, and shrinkage caused by uneven filling. The mold itself is made of high-quality mold steel (such as H13) and undergoes high-precision CNC machining, electrospark forming, and mirror polishing to ensure precise cavity dimensions and a smooth surface. This ensures the geometric accuracy and surface quality of the die-cast parts, meeting the stringent assembly tolerances required for laboratory instruments.3. Advanced Materials Improve Flow and FormabilityTo meet the filling requirements of thin-walled structures, laboratory instrument die castings and molds often use aluminum alloys with excellent flowability, such as ADC12, A380, or the higher-end AlSi10Mg. These alloys exhibit excellent flowability and low hot cracking tendency at high temperatures, enabling rapid filling of thin-walled areas during high-speed mold filling without cracking or cold shuts. Furthermore, alloy composition optimization and melt refining processes (such as degassing and slag removal) reduce inclusions and porosity, improve casting density, and ensure the structural integrity and mechanical properties of thin-walled areas.4. Precise Control of Process Parameters Ensures Molding QualityPrecise control of parameters such as temperature, pressure, speed, and time is crucial during the die casting process. For example, mold temperature must be maintained between 180–250°C to prevent underfilling caused by excessive cooling of the molten metal. The injection speed must be adjusted in stages, starting slowly to expel air from the cavity and then rapidly increasing during the filling phase to ensure adequate filling of thin-walled areas. Furthermore, vacuum die-casting or oxygen pressure die-casting techniques can effectively reduce gas entrapment within the mold cavity, lower porosity, and enhance the density and mechanical strength of thin-walled castings. These technologies are particularly suitable for instrument components that require vacuum sealing or withstand pressure.5. Synergistic Achievement of Structural Optimization and Lightweight DesignLaboratory instruments strive for high precision and portability. Therefore, die-casting often utilizes topological optimization design. While maintaining structural rigidity, redundant material is removed to create lightweight structures such as hollow sections, reinforced ribs, and hollowing. These designs not only reduce the overall weight of the instrument but also optimize stress distribution in thin-walled areas, avoiding deformation or cracking caused by localized stress concentration. Furthermore, integrated die-casting reduces the number of parts and connection points, improving the instrument's shock resistance and long-term stability.6. Post-processing and testing ensure final performanceAfter forming, die-cast parts undergo deburring, heat treatment (such as T6 solution aging), and surface treatment (such as anodizing and spray coating) to enhance dimensional stability, corrosion resistance, and aesthetic quality. For key components, X-ray inspection, coordinate measurement (CMM), or CT scanning are also used to detect internal defects and geometric accuracy, ensuring that every die-cast part meets the high standards required for laboratory instrumentation.The ability to achieve complex, thin-walled structures in laboratory instrument die castings and molds is a result of advanced die-casting processes, precision molds, high-quality materials, intelligent design, and strict quality control. This high-precision, highly integrated manufacturing capability not only meets the lightweight, high-rigidity, and precision assembly requirements of modern analytical instruments, but also provides solid support for instrument performance improvements and miniaturization.
