Realization of ductile regime machining in micro-milling SiCp/Al composites and selection of cutting parameters

2018 ◽  
Vol 233 (12) ◽  
pp. 4336-4347 ◽  
Author(s):  
Junwei Liu ◽  
Kai Cheng ◽  
Hui Ding ◽  
Shijin Chen ◽  
Liang Zhao
Keyword(s):  
Size Effect ◽  
Surface Quality ◽  
End Milling ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Micro Milling ◽  
Machined Surface ◽  
Side Milling ◽  
Ductile Regime Machining ◽  
Fracture Damage

SiCp/Al composites are widely used owing to their outstanding performance. However, due to the existence of brittle SiC, surface defects caused by particle fracture damage the surface quality severely. Meanwhile, due to small cutting parameters during the micro-milling process, especially the undeformed chip thickness, which is mainly determined by the feed per tooth, the size effect of matrix also damages the surface quality. In this study, a method by realizing the ductile regime machining of the particle and diverting away the defects of particles and matrix is proposed to select the cutting parameters and improve the surface quality in micro-milling SiCp/Al composites. Suitable range of values of the feed per tooth for side milling and end milling are obtained by this method and validated by micro-experiments. The results show that the size effect of Al and removal ways of the SiC particles affect the machined surface simultaneously. By using suitable feed per tooth, weak size effect of Al and most of the particles’ ductile regime removing can be realized, leading to the generation of the best surface. Additionally, the machining effects of this method are more prominent in end milling than in side milling.

Experimental investigation of the influence of cutting parameters on surface quality and on the special characteristics of micro-milled surfaces of hardened steels

2021 ◽  
pp. 095440622110130
Author(s):  
Barnabás Zoltán Balázs ◽  
Márton Takács
Keyword(s):  
Surface Quality ◽  
Surface Profile ◽  
Cutting Parameters ◽  
Relevant Information ◽  
Milling Process ◽  
Micro Milling ◽  
Machined Surface ◽  
Analysis Of Dynamics ◽  
Five Axis ◽  
Coated Carbide

Micro-milling is one of the most essential technologies to produce micro components, but due to the size effect, it has many special characteristics and challenges. The process can be characterised by strong vibrations, relatively large run-out and tool deformation, which directly affects the quality of the machined surface. This paper deals with a detailed investigation of the influence of cutting parameters on surface roughness and on the special characteristics of micro-milled surfaces. Several systematic series of experiments were carried out and analysed in detail. A five-axis micromachining centre and a two fluted, coated carbide micro-milling tool with a diameter of 500 µm were used for the tests. The experiments were conducted on AISI H13 hot-work tool steel and Böhler M303 martensitic corrosion resistance steel with a hardness of 50 HRC in order to gain relevant information of machining characteristics of potential materials of micro-injection moulding tools. The effect of the cutting parameters on the surface quality and on the ratio of Rz/ Ra was investigated in a comprehensive cutting parameter range. ANOVA was used for the statistical evaluation. A novel method is presented, which allows a detailed analysis of the surface profile and repetitions, and identify the frequencies that create the characteristic profile of the surface. The procedure establishes a connection between the frequencies obtained during the analysis of dynamics (forces, vibrations) of the micro-milling process and the characterising repetitions and frequencies of the surface.

Experimental investigation of top burr formation in high-speed micro-milling of Ti6Al4V alloy

2019 ◽  
Vol 234 (4) ◽  
pp. 730-738 ◽  
Author(s):  
Mohan Kumar ◽  
Vivek Bajpai
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
End Milling ◽  
Cutting Parameters ◽  
Ti6al4v Alloy ◽  
Micro Milling ◽  
Burr Formation ◽  
Machined Surface ◽  
Burr Width ◽  
Super Alloy

Miniaturization with superior quality product of super alloy is the demand of the industry. Ti6Al4V is the demanding super alloy due to its excellent material properties, although this super alloy is known for poor machinability in terms of burr formation, low tool life, and poor surface finish. Therefore, being a popular super alloy, it comes under the difficult-to-cut material. In the current work, burr formation on the machining of Ti6Al4V has been studied. Experimental investigation and characterizations of top burr formation on Ti6Al4V alloy using end milling process were carried out. A scanning electron microscopy identifies the burr formed on the machined surface. A new technique has been introduced to measure the top burr width (i.e. equivalent width) accurately. Equivalent burr width calculated as the ratio of total area of burr generated to the total height. It was observed that equivalent burr width in up milling was increased by 120%, while in down milling, it was decreased by 50% as the speed varies from conventional to high speed. Furthermore, the effects of different cutting parameters and tool parameters on top burr formation have been analyzed to establish correlation among them.

scholarly journals Research on Parameter Optimization of Micro-Milling Al7075 Based on Edge-Size-Effect

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 197 ◽  
Author(s):  
Yinghua Chen ◽  
Tao Wang ◽  
Guoqing Zhang
Keyword(s):  
Size Effect ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Micro Milling ◽  
Milling Force ◽  
Milling Tool ◽  
Cutting Parameters Optimization ◽  
Strong Size Effect ◽  
Edge Size

In the process of micro-milling, the appearance of the edge-size-effect of micro-milling tools cannot be ignored when the cutting parameters are smaller than the cutting edge arc radius (r0) of the micro-milling tool or close to it, and it could easily lead to low cutting efficiency and poor surface quality of the micro-slot. Through micro-milling experiments on Al7075-T6 materials, the change of milling force in the plough zone and shear zone during micro-milling was studied, and the minimum cutting thickness (hmin) range was determined to be 0.2r0–0.4r0 based on r0 of the micro-milling tool. Subsequently, the effect of fz/r0 (fz denotes feed rate per tooth) on the top burr formation of the micro-slot, the surface roughness (Ra) of the micro-slot bottom, and the milling force was studied, and a size-effect band of micro milling was established to determine the strong size-effect zone, transition size-effect zone, and the weak size-effect zone. Finally, two different fz/r0 in the strong size-effect zone and the weak size-effect zone are compared, which proves that the main purpose of the cutting parameters optimization of micro-milling is to avoid cutting parameters locating in the strong edge-size-effect zone. The above conclusions provide a theoretical basis for the selection of micro-milling cutting parameters, and an important reference in improving the surface quality of micro-milling.

Cutting Parameters Impacting on Tool Wear in Micro End-milling of Tool Steel

2018 ◽  
Author(s):  
Cínthia Soares Manso ◽  
Cleiton Lazaro Fazolo de Assis ◽  
Luciana Wasnievski da Silva de Luca Ramos ◽  
Erik Gustavo Del Conte
Keyword(s):  
Tool Wear ◽  
Tool Steel ◽  
End Milling ◽  
Cutting Parameters ◽  
Milling Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Machined Surface ◽  
Tool Diameter

In micro milling process, the quick wear and premature breakage of tools configure a problem that affects not only the process costs but also the manufacturing quality. This work investigates the influence of the cutting parameters on tool wear and surface roughness in a dry machining of a tool steel H13 workpiece (X40CrMoV5-1). Spindle speed was kept constant (27200 rpm) and two feeds per tooth were applied (1.5 and 3.0 µm) as depth of cut (25 and 30 µm), and variating cut length as well. The wear of the tool top area, tool diameter and nose radius were monitored during micro milling tests. Roughness was evaluated by using a Laser Confocal Microscope. The lower level of feed per tooth and depth of cut showed lower roughness, but a higher tool wear. A balance between cutting parameters and cutting length must be considered to ensure micromachining without severe tool wear and preserve microchannel features along its machined surface.

Simulation and Experimental Study on Size Effect in Steel Micro Milling Machining Process

2012 ◽  
Vol 602-604 ◽  
pp. 2021-2026 ◽  
Author(s):  
Chun Jiang Zhou ◽  
Jian Cheng Liu
Keyword(s):  
Size Effect ◽  
High Speed ◽  
Chip Thickness ◽  
Critical Factor ◽  
Machining Process ◽  
Micro Milling ◽  
Exit Point ◽  
Machining Processes ◽  
Machined Surface ◽  
Optimal Cutting Parameters

Size effect is a critical factor that needs to be considered when conducting micro mechanical machining processes. In this paper, a cutting process simulation technology is used to simulate a single tooth’s engagement with workpiece from the entry point to the exit point in a slot milling operation. The obtained specific cutting forces from simulation are employed to analyze the size effect and the minimum chip thickness with variable radii of tool edges. Micro machining experiments with different machining conditions are implemented by use of a high speed and high precision machining spindle to investigate the size effect on machined surface integrity and burr width. The optimal cutting parameters have been analyzed based on the simulation and cutting test results.

Improving surface quality in microcutting of 10B/Al composite

2019 ◽  
Vol 71 (5) ◽  
pp. 672-676
Author(s):  
Xingjun Wang ◽  
Zhuoran Yang ◽  
Feifei Xu ◽  
Liping Wang
Keyword(s):  
Surface Quality ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Surface Generation ◽  
Particle Removal ◽  
Uncut Chip Thickness ◽  
Machined Surface ◽  
Content Type ◽  
Al Composite

Purpose The microcutting performance of the 10B/Al composite is significantly poor because of the existence of hard boron particles. The effects of cutting parameters, including uncut chip thickness and cutting speed, on the material removal mechanism and surface generation are investigated to improve the surface quality. Design/methodology/approach The 2D finite element model, which includes a rigid cutting tool, a reinforced phase, a matrix and a dense layer, is established. The effects of uncut chip thickness on material removal mechanism and surface generation are analyzed from a probabilistic perspective. The relationship between the uncut chip thickness and the probability in which the machined surface will have a better surface quality is constructed. A Gaussian distribution formula is applied to describe the machined surface quality. Findings Two representative particle-removal modes, namely, cutting-through and pulling-out modes, are observed. For cutting-through mode, when the relative cutting location is small, better surface quality is obtained. For pulling-out mode, the quality of the machined surface gradually improves because the further increase of the relative cutting location reduces the height of the generated pit and scratches. The microcutting at high cutting speed tends to suppress the scratch phenomenon. The best surface quality will be obtained at small uncut chip thickness and high cutting speed. Originality/value The surface quality generated in microcutting of the 10B/Al composite can be improved by optimizing the cutting parameters and controlling the particle-removal modes based on the proposed Gaussian distribution formula.

An experimental analysis of minimum chip thickness in micro-milling of two different titanium alloys

2020 ◽  
Vol 234 (12) ◽  
pp. 1486-1498 ◽  
Author(s):  
Kubilay Aslantas ◽  
Luqman KH Alatrushi ◽  
Fevzi Bedir ◽  
Yusuf Kaynak ◽  
Nihat Yılmaz
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Ti6al4v Alloy ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Minimum Chip Thickness ◽  
Burr Width

Micro-milling is a micro-mechanical cutting method used to obtain complex and three-dimensional micro geometries. Micro-cutting tools are used in the manufacturing of micro-components and the type of workpiece is also important for good surface quality and minimum burr. In this study, micro machinability of Ti6Al4V alloy which is used most frequently in micro-component production is compared with Ti5553 alloy. Micro-milling of Ti5553 alloy and comparison of the minimum chip thickness with Ti6Al4V were performed for the first time in this study. Using different cutting parameters, the variation of surface roughness, burr width, and cutting forces were investigated. The cutting tests were carried out on a specially designed and high-precision micro-milling test system using a TiCN-coated two-flute end mill of 0.6 mm diameter. According to the results, minimum chip thickness is approximately 0.3 times the edge radius of the cutting tool and does not vary with the alloy type. At feed rates smaller than the minimum chip thickness, both the cutting forces increase and the surface quality decreases. For both alloys, reduced feed rate and increased depth of cut lead to increased burr width. The burr widths in Ti6Al4V alloy are higher. At the end of the study, the limits of the cutting parameters where plowing occurred for the both alloys are clearly determined. In addition, the limits of the cutting parameter causing plowing have been confirmed by cutting forces, surface roughness, and burr formation.

Development of the cBN Electroplated End-Mill for High Precision Machining of CFRP

2020 ◽  
Author(s):  
Shinnosuke Yamashita ◽  
Tatsuya Furuki ◽  
Hiroyuki Kousaka ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
...  
Keyword(s):  
Surface Roughness ◽  
End Milling ◽  
Drop Out ◽  
End Mill ◽  
Machined Surface ◽  
Side Milling ◽  
Reinforced Plastics ◽  
Milled Surface ◽  
Grinding Conditions ◽  
Grinding Tool

Abstract Recently, the demand of carbon fiber reinforced plastics (CFRP) has been rapidly increased in various fields. In most cases, CFRP products requires a finish machining like cutting or grinding. In the case of an end-milling, burrs and uncut fibers are easy to occur. On the other hand, a precise machined surface and edge will be able to obtain by using the grinding tool. Therefore, this research has been developed a novel the cBN electroplated end-mill that combined end-mill and grinding tool. In this report, the effectiveness of developed tool was investigated. First, the developed tool cut the CFRP with side milling. As the result, the cBN abrasives that were fixed on the outer surface of developed tool did not drop out. Next, the end-milled surface of CFRP was ground with the developed tool under several grinding conditions based on the Design of Experiment. Consequently, the optimum grinding condition that can obtain the sharp edge which does not have burrs and uncut fibers was found. However, surface roughness was not good enough. Thus, an oscillating grinding was applied. In addition, the theoretical surface roughness formula in case using the developed tool was formularized. As the result, the required surface roughness in the airplane field was obtained.

Investigation on micro-milling of micro-grooves with high aspect ratio and laser deburring

2019 ◽  
Vol 234 (5) ◽  
pp. 871-880 ◽  
Author(s):  
Yinfei Yang ◽  
Jinjin Han ◽  
Xiuqing Hao ◽  
Liang Li ◽  
Ning He
Keyword(s):  
Aspect Ratio ◽  
Tool Wear ◽  
Surface Quality ◽  
High Aspect Ratio ◽  
High Conductivity ◽  
Cutting Fluid ◽  
Micro Milling ◽  
Free Alcohol ◽  
Processing Efficiency ◽  
Machined Surface

High aspect ratio micro-grooves are critical structures in the micro-electromechanical system. However, problems like rapid tool wear, low processing efficiency, and inferior machined quality in micro-milling of high aspect ratio micro-grooves by length–diameter ratio tools are particularly significant. In this work, a combined micro-milling method based on water-free alcohol as the cutting fluid and laser deburring is proposed to investigate the high aspect ratio micro-groove generation of oxygen-free high-conductivity copper TU1. Parametric experiments and high aspect ratio micro-groove experiments were conducted to investigate the surface quality, cutting forces, and tool wear. The water-free alcohol was employed to improve the tool life and machined surface quality. In the case of the oxygen-free high-conductivity copper TU1 material, a satisfactory high aspect ratio micro-groove (groove-width = 0.2 μm and aspect ratio = 2.5) with a nanoscale surface roughness ( Ra = 68 nm) was obtained under the preferred machining conditions. Furthermore, the deburring process of the high aspect ratio micro-groove by the laser technology was conducted to achieve ideal machined quality of the top surfaces.

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