Surface Topography In Milling Research Articles

A high efficiency 3D surface topography model for face milling processes

Predicting the 3D surface topography in milling is the basis of analyzing its surface contact properties. However, most studies have been devoted to improving the accuracy of models and ignoring the efficiency of models, which has resulted in predicting the surface topography of large-size face milling becoming a time-consuming task. In this paper, a high efficiency 3D surface topography prediction model was proposed for face milling processes. The high efficiency of the proposed model was demonstrated by reducing the data volume and optimizing algorithms. First, a traditional 3D surface topography model was developed. Then, a high efficient 3D surface topography model was proposed based on the optimization of the data volume and algorithms. Next, the validity of the proposed model was verified by face milling experiments. Finally, compared with traditional models and other models, the proposed model had the highest computational efficiency. The proposed model provides a method for surface topography analysis of large-size face milling and an insight for optimizing other models.

A comparative study on surface topography and microhardness of laser polished-hardened AISI D2 tool steel

Although a laser beam with a small diameter (< 1 mm) can significantly improve surface morphology, the polishing efficiency is very low, and the improvement of surface hardness is negligible. In this work, a novel laser polishing-hardening (LPH) method with integration and high efficiency for the treatment of AISI D2 tool steel using a large-size laser beam (Φ2.8 mm) was proposed, and the effects of laser hardening (LH), laser polishing (LP), and LPH treatments on the surface topography and microhardness were examined. The results show that the LH method had a negligible effect on the surface roughness of the treated sample, while the surface roughness Ra of LP and LPH specimens was reduced by 74.6% and 80.9%, respectively, indicating that the milled surface topography had been significantly improved, especially LPH was more effective in reducing the roughness. Besides, the polishing efficiency of LPH was 10 times that of the LP approach. In terms of hardness improvement, the near-surface microhardness of LH and LPH samples increased by 1.5 times and 1.3 times, respectively, and the effective hardened zone (EHZ) depth was 0.42 mm and 0.24 mm, respectively, demonstrating that these two laser processing methods had a beneficial effect on the cross-section microhardness of D2 tool steel, while the increase of LP on the microhardness was insignificant. The comprehensive analysis of the surface morphology and microhardness of the LPH specimen indicates that LPH was a feasible laser surface treatment method for D2 tool steel. On the premise of ensuring a high surface finish, the polishing efficiency can be remarkably improved, and the subsurface microhardness and EHZ depth of processed specimen can be also significantly increased, which provided a feasible idea for the application of laser surface treatment technology in industrial mold production.

Trajectory Dependent Structural Vibration and Its Effects on Surface Generation

The vibration of machine tool plays an important role in surface generation. However, the vibration characteristics is different for different machine tool structures and different machining path. This paper proposed a new method of structural sensitivity analysis to identify trajectory dependent structural vibration and its effect on surface generation in milling. The experimental and theoretical results verify that (i) Multimode low-frequency vibration of the sensitive structures (MLFVSS) directly determines the surface topography in milling; (ii) The sensitivity is different for different structures or the same structure at different modes; (iii) Structural vibration characteristics is related to the machining path, resulting in different influence of the structural vibration on surface generation at different position of the machining path. Finally, a surface topography prediction model was established based on the experimental results. This study is helpful to the optimization of machine tool structures and the selection of machining parameters.

The effect of characteristics of free-form surface on the machined surface topography in milling of panel mold

In the milling process of automobile panel mold of hardened steel, the characteristic of free-form surface is one of the dominant factors for surface topography. In this paper, the trajectory of cutting edge is firstly modeled to analyze the residual height of the free-form surface in ball-end milling of hardened steel. Furthermore, the non-uniform rational B-splines (NURBS) surface reconstruction is utilized to generate the surface topography. Subsequently, the influences of surface curvature, lead angle, milling vibrations on the machined surface topography, and residual height are investigated, respectively. Finally, the accuracy of the surface topography and the roughness prediction model are validated by the milling experiments of free-form surface, where two-dimensional contour maps could be obtained. The simulation and experimental results demonstrate that the machined surface topography of hardened steel is fitted by means of NURBS surface reconstruction. In that manner, the effects of surface characteristics on the machined surface topography can be accurately predicted.

Surface topography and roughness of high-speed milled AlMn1Cu

The aluminum alloy AlMn1Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-speed milling experiments are carried out in order to improve the machining quality and reveal the machining mechanism. The typical topography features of machined surface are observed by scan electron microscope(SEM). The results show that the milled surface topography is mainly characterized by the plastic shearing deformation surface and material piling zone. The material flows plastically along the end cutting edge of the flat-end milling tool and meanwhile is extruded by the end cutting edge, resulting in that materials partly adhere to the machined surface and form the material piling zone. As the depth of cut and the feed per tooth increase, the plastic flow of materials is strengthened and the machined surface becomes rougher. However, as the cutting speed increases, the plastic flow of materials is weakened and the milled surface becomes smoother. The cutting parameters (e.g. cutting speed, feed per tooth and depth of cut) influencing the surface roughness are analyzed. It can be concluded that the roughness of the machined surface formed by the end cutting edge is less than that by the cylindrical cutting edge when a cylindrical flat-end mill tool is used for milling. The proposed research provides the typical topography features of machined surface of the anti-rust aluminum alloy AlMn1Cu in high speed milling.

Analiza wpływu zawartości TiC w nanokompozycie na topografię powierzchni po obróbce frezowaniem

Analiza wpływu zawartości TiC w nanokompozycie na topografię powierzchni po obróbce frezowaniem

Multi Tooth Uneven Cutting Behavior of High-speed Milling Cutter and Criterion for Milled Surface Topography

With the cutting model of high-speed milling cutter in vibration condition, milling cutter vibration and effect of tooth error on cutting parameter are researched and high-speed milling cutter multi tooth uneven cutting behavior characterization methods are proposed. Use of high speed milling cutter cutting experiments and simulation results of surface topography, processing surface morphology characteristic parameters of cutter multi-tooth uneven cutting behavior response characteristics are revealed under the influence of milling cutter vibration and error, surface topography criterion is established in the cutting behavior of high speed milling cutter with multi-tooth, judgment method of multitooth uneven cutting behavior of high speed milling cutter with multi-tooth is proposed. Use the above criteria and evaluation method, reveal the formation mechanism of multi tooth uneven cutting, proposed compensation method of multi tooth uneven cutting behavior of high-speed milling cutter and do an experiment to verify the method.

Analysis Method for Surface Topography Model in High Speed Milling Hardened Steel

During high speed milling hardened steel, the problem that tool vibration reducing machining surface quality causes led to a research for the influence characteristics of milled surface topography through high speed milling experiment. To determine the formation condition of milled surface topography, using displacement increment of origin of tool coordinate system which is caused by the milling cutter vibration and installation error, modifies the cutting motion trajectory. Based on the tool-workpiece contact relationship and the cutting layer parameters of contact points on two teeth, the residual units of machined surface are established, thereby proposing a solution method for the deformation and distribution characteristic of residual units under the overhanging volume and the vibration. Therefore, the milled surface topography of cutting hardness steel with high speed ball-end milling cutter is revealed to bring out a striking contrast between the simulation and experiment of milled surface topography of hardness steel.

Choice of reference surfaces for machined surface roughness in milling of SiCp/Al composites

In order to choose the appropriate reference surface on the machined surface roughness of SiCp/Al composites, the cutting experiments of SiCp/Al composites were carried out, and the machined surface topography was measured by OLS3000 Confocal laser scanning microscope. The 3D measured data of machined surface topography were analyzed by the area power spectrum density. The result shows that the texture of machined surface topography in milling of SiCp/Al composites is almost isotropic. This is the reason that the values of R q at different locations on the same machined surface are obviously different. Through the comparison of performance of different filtering methods, the robust least squares reference surface can be used to extract the surface roughness of SiCp/Al composites effectively.

Model based reconstruction of milled surface topography from measured cutting forces

This paper presents a method for the reconstruction of surface topographies of peripheral milled surfaces based on measured cutting forces. Even under stable process conditions, machine tool vibrations occur due to the milling tool's dynamic excitation. In order to estimate the influence of tool vibrations on surface degradation, a dynamic tool model is developed and applied to a material removal model. The proposed tool model is able to reconstruct the accurate shape and roughness of machined surfaces. The developed method is verified by comparing the reconstructed and the measured surface topographies. The results demonstrate that the method is able to reconstruct the surface topography of the machined workpiece from measured resultant cutting forces and it can be used also for the online monitoring of milling processes.

Simulation and experimental investigation of the end milling process considering the cutter flexibility

In this paper, a new type of model for the end milling process is presented considering cutter flexibility, which includes not only the static but also the dynamic deflection of the cutter. According to the basic assumption for a linear elastic body, the force acting on the cutter and its deflection in the milling process are both divided into two parts: the static and the dynamic. By considering the regenerative feedback in the practical milling process, the dynamic milling force acting on a unit length of the cutter is derived. Furthermore, a new kind of dynamic deflection model of the cutter is established. Based on this model, a new set of efficient numerical simulation algorithms are presented. In the mean time, the static deflection of the cutter is also formulated. Finally, the simulation and measurement of the milled surface topography for the end milling process show the feasibility of this model.

Generalized simulation model for milled surface topography-application to peripheral milling

Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector operation, the trajectory equation of cutting edge relative to workpiece is derived. Then, a three-dimensional topography simulation algorithm is constructed through dividing the workpiece into regular grids. Finally, taking the peripheral milling process as an example, the generalized model is simplified, and the corresponding simulation examples are given. The results indicate that it is very efficient for the generalized model to be used to analyze and simulate the peripherally milled surface topography.