Analysis of characteristics of arc shape caused by intermittent cutting force and dynamic vibration in ultra-precision cutting processes

Abstract

This article analyzes the phenomenon of “arc shape” in surface characteristics caused by dynamic vibration in ultra-precision machining. First, a surface simulation model is proposed based on the effect of the tool shape on the cutting profile. The accurate mapping relationship between spindle speed, feed speed, relative vibration, and the motion track of the tool tip to the workpiece profile is also established. Thereafter, the input frequency spectrum signature of an intermittent cutting force is found to be determined by the spindle speed and workpiece characteristics, and this is verified by experimental results. A phased, self-regulated mode of forced vibration caused by intermittent cutting force is then proposed, and the forming of the arc shape feature is explained. In addition, it is revealed that output vibration can be kept at a low level by adjusting the spectrum curve of the input signal.

A novel tool wear suppression method for polycrystalline diamond by applying magnetic field in turning of ferrous materials

“…16,17 Compared to traditional turning, ultraprecision turning is characterised with a qualitative change and mainly employs diamond tools. 18,19 Diamond is a typical diamagnetic material that is not magnetised by MF. Therefore, further experiments are needed to study the influence of the MF on the diamond tool wear in ultraprecision turning of ferrous materials.…”

A novel anisotropic assessment method for nanometric surface roughness of ultra-precision diamond milling

“…In ultra-precision machining, ultra-precision diamond milling (UPDM) provides a very satisfactory solution for machining optical freeform surface with nanometric surface roughness (NSR). 1,2 The NSR is that part of surface residual in material removal process, greatly influenced by environments, 3 chip formation such as lamellar chips 4 and different structured chips, 5 tool wear such as mechanical, physical, and chemical wear, 6 tool geometry, 3 cutting parameters, 3 material effects such as material-induced factor, 7 material removal rate, 8 and material characteristics, 9 and machine tool dynamics 10 such as spindle vibration 11 and air-induced vibration, 12 etc. It would yield a crucial impact upon the optical performances of the machined surface.…”