Improvement of technology of manufacturing and control of quality of mirrors-reflectors from aluminium alloy

At present, the technology of diamond blade whetting with nano-sized roughness is widely used at the manufaсturing of metal-optical products, first of all, mirror-reflectors for “transportation” of powerful laser energy flows. Optimum material for mirror-reflectors is an aluminum alloy AMg2, which surface purity, is affected by the quality of preliminary mechanical heat treatment during superfinishing treatment by diamond whetting.

Preliminary machining of the surface with a carbide cutter and finishing with a diamond cutter (with a radius of curvature of the blade less than 0.05 μm) were performed on a precision lathe of the MK 6501 model with a vertical spindle position on an air bearing. Thermal treatment was carried out in the laboratory electric furnace SNOL 58/350. Various modes of preliminary heat treatment, machining with a carbide cutter and finishing with a diamond cutter of substrates (20×20×7 mm³) were tested. The surface state analysis was carried out using the PMT-3 microhardness tester, the SolverPro P47 atomic-force microscope (AFM), and the experimental probe-electrometry device. The control of the electrophysical parameters of the surface was carried out by recording the distribution of the electron work function (RWF) by the contact potential difference with the processing by the microprocessor measuring transducer of electrostatic potentials. The recorded changes in the RWF characterize the physic-chemical and mechanical parameters of the surface of mirrors and indicate the presence of a different type and nature of defects.

Modified preliminary mechanical-thermal treatment allowed to improve the cleanliness of surface treatment of substrates. Finishing nanoscale diamond blade processing, including the complete removal of the surface layer that was disturbed by previous operations, bring to the greatest possible improvement in the quality of the surface in terms of the uniformity of the distribution of its electrophysical properties. As a result, according to the values and changes of the RWF, achievement of the specified performance characteristics of the product surface was monitored in order to optimize the technological processing modes in accordance with the functional designations of the devices.

The methods for increasing the efficiency of nanoscale diamond blade processing and performing researches of the electrophysical properties of the surface to control defects in the manufacture of metal reflector mirrors with high reflectivity and radiation strength for operation under extreme conditions.

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