Compliant grinding and polishing refers to a class of fine material processing methods relying on one or more system element being compliant with the workpiece surface in a controllable and reversible manner, thus being distinct from conventional rigid wheel grinding and polishing. The resulting surface adaptability greatly facilitates the ultra-precision machining of freeform surfaces, with a level of accuracy and productivity difficult to achieve with conventional rigid processing systems. Aiming for a comprehensive review of signal advances on this topic in the last decades, this paper introduces a multi-level compliance categorization system to sort between distinctive processes. For each category, various perspectives are explored that pertain to principles, methodologies, and physical properties such as material removal and surface integrity. Finally, relative merits are analyzed, together with a discussion of the outlook and future trends.

Compliant grinding and polishing: A review

The ultrasmooth optical components with atomic-order surface roughness and nanometre-level shape accuracy are in immense demand with the rapid advancement of modern optical technology. In r...

Review of several precision finishing processes for optics manufacturing

Experimental and theoretical investigation into surface roughness and residual stress in magnetorheological finishing of OFHC copper

A method of making magnetizable abrasive particles includes: moistening the outer surfaces of ceramic particles with waterglass to provide moistened ceramic particles. Magnetizable particles are contacted with the moistened ceramic particles to provide powder-coated ceramic particles. The powder-coated ceramic particles are heated to at least a temperature sufficient to bond the magnetizable particles of the powder-coated ceramic particles to the respective ceramic particles thereby providing the magnetizable abrasive particles. On a respective basis, each magnetizable abrasive particle comprises a respective ceramic particle having a magnetizable particles bonded thereto.

Magnetizable abrasive particle and method of making the same

The invention provides a magnetic grinding material. The magnetic grinding material comprises a magnetism sensing core, and a core housing structure of a grinding housing which wraps the magnetism sensing core, wherein the grinding housing comprises a binding agent and grinding material particles; the grinding material particles are adhered to the magnetism sensing core by hot melting the binding agent. According to the magnetic grinding material, the surface wrapping layer of the magnetism sensing core is reasonably designed, so that the grinding efficiency of the magnetic grinding material is improved, and the self-sharpening performance remains, and as a result, the consistency and stability of the grinding process can be ensured; the magnetism sensing material is used as the core of the magnetic grinding material; the magnetic grinding material is easy to recover. The invention further provides a preparation method of the magnetic grinding material. The preparation method comprises the steps of supplying the magnetism sensing core particles and the binding agent particles, and preparing and sintering semi-finished product, namely, small balls, of the magnetic grinding materials. According to the method, the grinding material particles and the magnetism sensing core particles are sintered through the high-temperature-sintered binding agent powder, so that the oxidizing degree of the magnetism sensing core particles can be effectively reduced. The preparation method is simple in processes, and industrial production is easily carried out.

Magnetic grinding material and preparation method thereof

The invention discloses a magnetic abrasive which comprises a magnetic material (1) in granule shape. The granular magnetic material serving as the kernel is wrapped with a ceramic layer or a plastic layer. A granular abrasive is bonded on the surface of the ceramic layer. During use of the magnetic abrasive composed of the components, the non-magnetic material layer wrapping the magnetic material (1) can improve the removal efficiency in grinding magnetic material by magnetic force and solve problems of thinned and residual abrasive particle to a certain degree. Compared with the conventional magnetic abrasive, the magnetic abrasive in the invention has greatly reduced residues, remarkably improved processing performance of an abrasive brush, and significantly improved processing efficiency of magnetic grinding on the magnetic material.

Magnetic abrasive material

An ultra-precision synergistic finishing process integrated MRF and ELID grinding was proposed for shorten total
finishing time and improve finishing quality. Sets of ultra-precision experiments were carried out to grind and finish
some optical glass BK materials. ELID grinding, as pre-finishing, was employed to obtain high efficiency and high
surface quality; and then, MRF, as the final finishing, was employed to improve further surface roughness and form
accuracy. BK13 plane glass was processed by integrated ELID grinding using #4000 wheel and MRF. After ELID
grinding, λ/5 P-V was obtained, and then, MRF 30 minutes, the form accuracy was improved to λ/28 P-V. Likewise,
curvature BK7 glass lens was also used to test. After ELID grinding using #4000 wheel, form accuracy λ/5 P-V and
surface roughness 261 nm rms were obtained; and then, MRF 17 minutes (2 cycles), the form accuracy and the surface
micro-roughness were improved to λ/18 P-V and 0.56 nm rms. By applying the ultra-precision synergistic finishing
process of ELID-grinding and MRF, the glass materials could be finished to sub-nanometer surface micro roughness and
~20 nm figure accuracy in a short time.

Ultraprecision finishing process integrated ELID grinding and MRF for BK glass

A new quality weight for phase reconstructing (PhR) in optical fringe measurement is proposed, which is based on the
combination of Log Modulation Amplitude and Phase Derivative Variance (LMAPDV). The LMAPDV quality weight is
successfully used to guide the path-following PhR operation. Moreover, by incorporating with the modulation
information, LMAPDV quality weight shows better performance in measuring the goodness of phase data than
conventional Phase Derivative Variance (PDV) quality weight. In order to deal with phase maps with strong noise and/or
low modulation, we introduce the LMAPDV quality weight into Least-Square (LS) PhR algorithm and compare it with
PDV quality weight. Numerical and experimental results demonstrate that the proposed quality weight has higher
reliability.

Quality weight based on log modulation amplitude for fringe analysis during optical fringe measurement

With the rapid development of information technology and electro-optical communication industry, various micro optical lenses have been used widely. Especially, because of great advantages concerning life, stability and imaging characteristics, the demand for glass lens is increasing the high-precision imaging. This paper studies on the ultra-precision parallel grinding technique of micro glass lens mould and investigates the form error compensation technique in grinding process. Grinding test of micro-lens mould with 10mm in diameter is conducted, and the surface roughness of R a 5.98nm, R z 34.95nm and form accuracy of PV 113nm eRMS 23nm are obtained. Key words: Micro-lens mould, Parallel grinding method, Form error compensation 1. INTRDUCTION In resent years, with the rapid development of information technology and electro-optical communication industry, plastic or glass micro lenses (with several millimeters to tens of microns in diameter usually) have been widely applied in consumptive electronic products such as digital camera, camera phone, microscope, CCD camera lens and medical instrument. Because of great advantage in the service life, stability and imaging characteristics, the demand for glass lenses is increasing in the field of high-precision imaging. Presently, micro glass lenses are mainly formed by hot press in the mass production, which needs micro ultra-precision moulds before micro-forming. This kind of mould requires high form accuracy (PV 300nm-100nm), nano-scale surface roughness and minimized subsurface damage. As for the fabrication of glass lens, the glass must be heated to 500-700 at first and then pressed. So the cemented carbide material is used [1-2]. According to the miniaturization and high-precision of glass lens mould, this paper applies the ultra-precision parallel grinding technique and form error compensation technique to fabricate micro lens mould. The micro wheel after precision truing and dressing is used. Micro-grinding test of micro-lens mould with 10mm in diameter is conducted.

Yongjian Zhu

Papers

Magnetic abrasive material

Ultraprecision finishing process integrated ELID grinding and MRF for BK glass

Quality weight based on log modulation amplitude for fringe analysis during optical fringe measurement

Fabrication of microglass lens mould by using ultraprecision microgrinding process