Review of non-conventional technologies for assisting ultra-precision single-point diamond turning

Ultra-precision single-point diamond turning (SPDT) is a recent realm in advanced manufacturing of optical components with nanometric features. SPDT has various applications in different industry sectors including space science, biomedical engineering, military, defense, and optics. However, different factors negatively impact the outcome of SPDT process and limit the success of optical surface generation. In addition, standard SPDT is based on the pure mechanical action of cutting and is limited when it comes to turning brittle and hard-to-machine materials. These materials have low machinability, and cutting them with diamond tool has been affected by high tool wear, short tool life, and consequently low quality of optical surface finish. Non-conventional machining techniques have been implemented to assist the purely mechanical SPDT process in order to eliminate the existing limitations, reduce effects of influencing factors, and enable an optimized machining environment. Different methods have been developed and used for assisting the SPDT process. In this review paper, recent trends and advances in technologies used for assisting SPDT are surveyed. Studying constructive and destructive effects of these SPDT-assisted technologies could provide necessary information for using the best possible solutions in diamond turning of different materials while improving targeted parameters. In addition, studying the effects of assisting technologies could provide a good perspective on hybrid SPDT process limitations and possible solutions. Although various techniques and solutions have been developed, there are still limitations for enabling an ultimate turning process. The paper highlights the possible trend of new technologies related to SPDT. More attention needs to be given, especially, to the development of novel techniques to completely solve existing limitations and enable best SPDT performance. Future studies need to be focused on the development of hybrid SPDT platforms, based on suitable combinations of non-conventional technologies, to achieve the best possible quality in terms of optical surface generation.