Chunyang Du

• Associate Professor
• National University of Defense Technology

Ion beam polishing (IBP) is the highest precision manufacturing technology widely applied in optical, semiconductor, and other fields. This chapter systematically introduces the theoretical foundations, process mechanisms, and practical implementations of IBP. First, the material removal mechanism based on ion sputtering theory is introduced, inclu...

The improvement of hardness and plasticity for material has been a significant challenge. This work employs molecular dynamics simulations to investigate the nanoindentation behavior of monocrystal AuPt alloys. The enhancement in both the hardness and plasticity of the alloy could be achieved by adjusting the crystal orientation and the composition...

Shear bands frequently appear in lattice architectures subjected to compression, leading to an unstable stress–strain curve and global deformation. This deformation mechanism reduces their energy absorption and loading-bearing capacity and causes the architectures to prioritize mechanical protection of external components at the expense of the enti...

In a supersonic cylindrical isolator at Mach 2, the structures and frequency characteristics of shock train flow fields were experimentally studied by the schlieren measurement method. According to the design principle of parallel light through schlieren windows in a cylindrical duct, a high-precision conformal optical window pair was designed and...

FeCoCrNiCu high-entropy alloys (HEAs) exhibit extraordinary mechanical properties and have the capability to withstand extreme temperatures and pressures. Their exceptional attributes make them suitable for diverse applications, from aerospace to chemical industry. We employ atomic-scale simulations to explore the effects of twinning boundary and t...

With the application spectrum moving from infrared to visible light, aluminum optics with complex forms are difficult to fabricate by the majority of existing processing methods. Possessing the highest machining precision and low processing contamination, ion beam figuring (IBF) is a better method for fabrication of aluminum optics. However, the su...

Benefiting from high specific stiffness and high reflectance, aluminum optics with a complex surface profile are widely used in aerospace optical systems which have strict requirements for volume of the systems. Contact figuring polishing process provides highly deterministic technology for the fabrication of high precision aluminum optics. However...

Aluminum optics are widely used in modern optical systems because of their high specific stiffness and high reflectance. With the applied optical frequency band moving to visible, traditional processing technology cannot meet the processing precision. Ion beam sputtering (IBS) provides a highly deterministic technology for high-precision aluminum o...

Weak-stiffness mirrors are widely used in various fields such as aerospace and optoelectronic information. However, it is difficult to achieve micron-level precision machining because weak-stiffness mirrors are hard to clamp and are prone to deformation. The machining errors of these mirrors are randomly distributed and non-rotationally symmetric,...

Aluminum optics are widely used in modern optical systems because of high specific stiffness and high reflectance. Magnetorheological finishing (MRF) provides a highly deterministic technology for high precision aluminum optics fabrication. However, the contamination layer will generate on the surface and bring difficulties for the subsequent proce...

Optical components with complex surfaces are widely applied. Ultra-precision diamond turning technology can fabricate these complex surfaces efficiently and accurately. Fast axis servo (FAS) system has the characteristics of large stroke and high frequency response. In this paper, Fast axis servo system based on linear rolling guide rail was used t...

Single point diamond turning (SPDT) is highly versatile in fabricating axially symmetric form, non-axially-symmetric form and free form surfaces. However, inevitable microstructure known as turning marks left on the surface have limited the mirror’s optical performance. Based on chemical mechanical polishing (CMP) mechanism, smoothing polishing (SP...

Ultra-smooth surfaces with low contamination and little damage are a great challenge for aluminum optical fabrication. Ion beam sputtering (IBS) has obvious advantages of low contamination and non-contact that make it a perfect method for processing aluminum optics. However, the evolution laws of aluminum surface morphology are quite different from...

Owing to its material properties, aluminum-based optical loads are widely used in the aerospace field. At present, the main processing of an aluminum alloy mirror is single-point diamond turning followed by the combined polishing process. The surface will generate some white crystals during the chemical mechanical polishing process (CMP). These cry...