Precision micro-milling process: state of the art

Abstract

Micro-milling is a precision manufacturing process with broad applications across the biomedical, electronics, aerospace, and aeronautical industries owing to its versatility, capability, economy, and efficiency in a wide range of materials. In particular, the micro-milling process is highly suitable for very precise and accurate machining of mold prototypes with high aspect ratios in the microdomain, as well as for rapid micro-texturing and micro-patterning, which will have great importance in the near future in bio-implant manufacturing. This is particularly true for machining of typical difficult-to-machine materials commonly found in both the mold and orthopedic implant industries. However, inherent physical process constraints of machining arise as macro-milling is scaled down to the microdomain. This leads to some physical phenomena during micro-milling such as chip formation, size effect, and process instabilities. These dynamic physical process phenomena are introduced and discussed in detail. It is important to remember that these phenomena have multifactor effects during micro-milling, which must be taken into consideration to maximize the performance of the process. The most recent research on the micro-milling process inputs is discussed in detail from a process output perspective to determine how the process as a whole can be improved. Additionally, newly developed processes that combine conventional micro-milling with other technologies, which have great prospects in reducing the issues related to the physical process phenomena, are also introduced. Finally, the major applications of this versatile precision machining process are discussed with important insights into how the application range may be further broadened.

Combined Processing of Micro Cutters Using a Beam of Fast Argon Atoms in Plasma

“…With an increase in the radius of the cutting edge about the thickness of the cut layer, the deformation area of the workpiece increases, and as a result, the force load on the tool tooth increases [31]. Cutting forces have a great influence on the chip formation nature, the process of material cutting, vibration characteristics of cutting, the integrity of the cutting tool, and the surface quality [59][60][61][62]. Additional surface treatment by fast atoms will reduce the cutting edge radius and prepare surfaces for the deposition of a wear-resistant coating while providing a relatively smaller radius of the cutting edge than when coating the surface without preparation of this kind.…”

Optimal tool design in micro-milling of difficult-to-machine materials

“…Following analysis and further optimisation of the FEA results, a verified optimum tool design is as increase lubricity [9], which will have great prominence in the near future of bio-implant manufacturing. However, the inherent issues of tool wear and poor machined surface quality in the micro-milling process currently reduce its effectiveness in such industries [10]. This is primarily true for machining of typical difficult-to-machine (DTM) materials commonly found in both mould and orthopaedic implant manufacturing [11].…”

Multi-objective optimization of Nd:Yag laser machining’s conflicting responses while milling micro-channels

“…3 The production of precise features of micro-scale requires machining with very tight tolerances, and machining accuracy becomes prime most important. 4–6…”

“…3 The production of precise features of microscale requires machining with very tight tolerances, and machining accuracy becomes prime most important. [4][5][6] Conversely, long pulse lasers generate large-sized heat-affected zone (HAZ) due to greater heat accumulation during machining and multiple recast layers. 7 Besides pulse length or duration, the laser scan track path is another critical parameter affecting heat accumulation apart from texture.…”