Simulation-Based and Experimental Investigation of Micro End Mills with Wiper Geometry

Abstract

One of the major advantages of micromachining is the high achievable surface quality at highly flexible capabilities in terms of the machining of workpieces with complex geometric properties. Unfortunately, finishing operations often result in extensive process times due to the dependency of the resulting surface topography on the cutting parameter, e.g., the feed per tooth, fz. To overcome this dependency, special tool shapes, called wipers, have proven themselves in the field of turning. This paper presents the transfer of such tool shapes to solid carbide milling tools for micromachining. In this context, a material removal simulation (MRS) was used to investigate promising wiper geometries for micro end mills (d = 1 mm). Through experimental validation of the results, the surface topography, the resulting process forces, and tendencies in the residual stress state were investigated, machining the hot work tool steel (AISI H11). The surface-related results show a high agreement and thus the potential of MRS for tool development. Deviations from the experimental data for large wipers could be attributed to the non-modeled tool deflections, friction, and plastic deformations. Furthermore, a slight geometry-dependent increase in cutting forces and compressive stresses were observed, while a significant reduction in roughness up to 84% and favorable topography conditions were achieved by adjusting wipers and cutting parameters.

Study on the Mechanism of Improving Surface Roughness of Gray Cast Iron Machining by Wiper Inserts

“…Fig. 1 Geometric principle of the conventional insert of the milling cutter [5] Selection of wiper inserts can be used to improve the above problems, from the structural analysis,wiper inserts is the transition between the main cutting edge and the sub-cutting edge,in fact, it's the distance from the subcutting edge of the theoretical tip of a section of the deformation area as shown Fig. 2.…”

“…[6] Fig. 2 Geometric principle of the wiper insert of the milling cutter [5] The choice of wiper insert can effectively improve the surface quality,near the tip of a section of the sub-cutting edge b s made vertical relationship with the center line of the tool, the section of the trimming edge plays a role in scraping. The use of a wiper insertcan effectively reduce the surface roughness value of the material.However, when the b s value is too large it leads to excessive cutting force and thus vibration, instead the material roughness value starts to increase.…”

Effect of Milling Processing Parameters on the Surface Roughness and Tool Cutting Forces of T2 Pure Copper

“…Therefore, to improve the cutting quality of the pure copper part, it is necessary to study the formation process of the machined surface topography during cutting. Many researchers use surface roughness to evaluate surface topography and to study the variation trend of surface topography under different processing parameters through cutting tests [ 6 , 7 ]. Su et al [ 8 ] used the orthogonal test method to analyze the roughness variation trend of the machined surface at different cutting speeds.…”