Lattice-filled TA15 titanium alloy optics housing for laser communication terminals: Design and dynamics validation

Space laser communication technology facilitates the rapid transmission of spacecraft observation data. The terminal equipment, characterized by its compact, lightweight, and energy-efficient design, imposes stringent requirements on the opto-mechanical structure. This study proposes a novel method to replace the aluminum-based silicon carbide (AlSiC) optics housing with a TA15 titanium alloy lattice-filled thin-walled structure. The lattice-filled optics housing structure was designed and manufactured within the constraints of structural size and the processability of additive manufacturing. With the energy-based homogenization method, the equivalent elasticity matrix and the coefficient of thermal expansion of the body-centered cubic lattice structure were calculated. Then, modal and thermal deformation analyses under a uniform temperature rise of 5°C were conducted. The first-order natural frequency reaches 1300 Hz, significantly exceeding the dynamic design requirement of 100 Hz. The thermal deformation is 16.1% lower than that of AlSiC housing. Next, additive manufacturing, machining, and black anodizing were performed on the design model. Despite a 50% increase in material density, the final weight of the TA15 lattice-filled structure is only 490 g compared to the 498 g AlSiC structure, while also reducing cost and machining time by approximately 50%. Finally, sinusoidal and random vibration tests were conducted on the prototype. The results demonstrated that the titanium alloy lattice-filled structure can withstand the harsh mechanical environment of spacecraft launch with high reliability. This work provides a new idea for the design and manufacture of lightweight, low-cost, and high-efficiency laser communication terminals, which can realize the batch substitution of AlSiC housings.