Micro cutting of steel

Abstract

Micro-cutting offers good potentialities in order to manufacture small and medium lot sizes of micro-parts with arbitary geometry at an economically reasonable expense. Either by direct machining or as a means to fabricate moulds for micro injection moulding, the major advantages turn out to be large removal rates, good compliance with tolerance ranges, high surface quality and a wide choice of materials which can be processed. Particularly if highly wear resistant materials are to be processed, as it is the case in mould fabrication for powder injection moulding, micro cutting of steel is a very eligible option. Consequently, the possibility to manufacture wear resistant micro structures of high aspect ratios by mechanical cutting is demonstrated with regard to its specific requirements in terms of transferability of the laboratory process into an industrial manufacturing process. Accordingly the paper focuses on process parameters and repeatability of machining results and machining capabilities.

Size effect and tool geometry in micromilling of tool steel

“…When micromachining inhomogeneous multi-phase material of different hardness and ductility for instance consisting of ferrite and pearlite, different ratios of cutting radius to grain size and varying phase ductility, imply that process mechanisms will differ [12,23]. Thus, Schmidt et al [23] preferred micromachining of finest and equidistantly distributed carbides steels or harder materials [12,22,23]. It can be concluded that to achieve a good surface finish for micromachining of steel with tungsten carbide tool, hard homogeneous material is the ideal choice [12,20].…”

“…Material properties, for example microstructure and hardness, also significantly influence the achievable surface roughness in micromachining [12,13,22]. When micromachining inhomogeneous multi-phase material of different hardness and ductility for instance consisting of ferrite and pearlite, different ratios of cutting radius to grain size and varying phase ductility, imply that process mechanisms will differ [12,23].…”

Characterization and optimization of the dynamic tool path of a highly dynamic micromilling machine

“…1 is shown to point out the dimensions of the used tools and work pieces. To enable the conventional use even of a small sized milling machine the structure and drive system has to be designed to provide ideal process parameters like path speeds of 1000 mm/min and accelerations of more than 1 g also for cutting forces above 150 N [1].…”

Design of micro square endmills for hard milling applications

“…Micromilling is a promising technology for the manufacturing of micro moulds from hardened tool steels [1,2] with three-dimensional features. It enables high production rates at lower cost where additional processing by EDM (electrical discharge machining) or ECM (electrochemical machining) could be reduced to a minimum, or even omitted.…”

“…The main problem encountered is poor tool performance in terms of low stiffness and edge strength causing premature breakage, severe wear, and short tool life [3][4][5][6][7][8][9]. As a result, the quality of the machined workpiece cannot match the required specifications in applications [2,[9][10][11][12][13][14][15]. Some researchers stated that micro cutting tools have become the bottleneck of the micromilling technology [16,17].…”