Performance of stone-plastic composites with different mix ratios during orthogonal cutting

2019 ◽  
Vol 9 (7) ◽  
pp. 749-756
Author(s):  
Zhaolong Zhu ◽  
Dietrich Buck ◽  
Xiaolei Guo ◽  
Mats Ekevad ◽  
Pingxiang Cao

The present study aimed to increase understanding of the machinability of stone-plastic materials with different mix ratios subjected to diamond planing. To that end, orthogonal cutting was carried out. Different stone-plastic materials were machined by diamond cutting tools to produce chips. Based on the results, four conclusions are drawn: (1) Among stone-plastic materials with decreasing polyvinyl chloride content ratio, the maximum cutting forces and fluctuation of dynamic forces show decreasing trends, and cutting stability increases. (2) The temperature of chips is slightly higher than that of tool edges; the cutting heat generated during machining is mainly absorbed by the chips of removed material and, to a lesser extent, stored in the tool edge. The type of stone-plastic material has a great effect on the changes in the temperatures of chip and tool edge. (3) With a decrease in polyvinyl chloride content, the chip shapes evolve from crack, to arc, and eventually to elemental chips. (4) The cutting quality of the machined surface improves with a decrease in the polyvinyl chloride content ratio of the stone-plastic materials.

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987806 ◽  
Author(s):  
Yanchun Ding ◽  
Guangfeng Shi ◽  
Hua Zhang ◽  
Guoquan Shi ◽  
Dongdong Han

The stagnant region often appears in front of the tool cutting edge, which is caused by mechanical inlay and excessive pressing in plastic metal cutting with large negative rake angle tools at a low speed. It results in the change of the effective negative rake angle which can affect the flow characteristics of material, the quality of machined surface and the abrasion loss of cutting tools. However, the critical negative rake angle model based on the existence of the stagnant region has not been reported yet. Therefore, in order to investigate the critical negative rake angle value considering the stagnant region, a critical negative rake angle model based on the principle of minimum required energy is established, and the correctness of the theoretical model is verified by orthogonal cutting experiments. At the same time, the influence of the critical value of the large negative rake angle tool on the machined surface quality is studied through different cutting experiments. These experimental results show that the deviations of both experimental and theoretical critical negative rake angle are less than 5% during the orthogonally cutting of the aluminium (AL1060) and copper (T2) materials by the negative rake angle tool. Meanwhile, the critical negative rake angle is related to the adhesive friction coefficient of tool–workpiece contact surface. The analysis of friction characteristics shows that the deviation values of both theoretical and experimental critical negative rake angle are proportional to the coefficient of adhesive friction and the thickness of the stagnant region. Critical negative rake angle has a significant effect on roughness and residual stress of the machined surface.


2019 ◽  
Vol 9 (7) ◽  
pp. 1373 ◽  
Author(s):  
Zhaolong Zhu ◽  
Dietrich Buck ◽  
Xiaolei Guo ◽  
Pingxiang Cao ◽  
Mats Ekevad

This paper investigated the machinability of a stone–plastic composite (SPC) via orthogonal cutting with diamond cutters. The objective was to determine the effect of cutting depth on its machinability, including cutting forces, heat, chip formation, and cutting quality. Increased cutting depth promoted an increase in both frictional and normal forces, and also had a strong influence on the change in normal force. The cutting temperatures of chips and tool edges showed an increasing trend as cutting depth increased. However, the cutting heat was primarily absorbed by chips, with the balance accumulating in the cutting edge. During chip formation, the highest von Mises strain was mainly found in SPC ahead of the cutting edge, and the SPC to be removed partially passed its elastic limit, eventually forming chips with different shapes. Furthermore, the average surface roughness and the mean peak-to-valley height of machined surfaces all positively correlated to an increase in cutting depth. Finally, with an increase in cutting depth, the chip shape changed from tubular, to ribbon, to arc, to segmental, and finally, to helical chips. This evolution in chip shape reduced the fluctuation in cutting force, improving cutting stability and cutting quality.


2018 ◽  
Author(s):  
Han Wu ◽  
J. Ma ◽  
Shuting Lei

In this paper, a coupled Eulerian-Lagrangian (CEL) finite element model is developed based on FEM software package Abaqus to solve the evolution of the dislocation density and grain size simultaneously. This validated CEL FEM model is then utilized to investigate the effects of microgrooved cutting tools on the evolution of dislocation density and grain size in orthogonal cutting of commercially pure titanium (CP Ti). Microgrooved cutting tools are cemented carbide (WC/Co) cutting inserts with microgrooves on the rake face. The effects of microgroove width and microgroove convex width are investigated in terms of cutting force, chip morphology, dislocation density, and grain size. It is concluded that this CEL FEM model can capture the essential features of orthogonal cutting of commercially pure titanium (CP Ti) alloy using microgrooved cutting tools. It is also concluded that microgroove width and convex width have substantial influence on the dislocation density profiles and grain size profiles along the depth from the machined surface and the tool-chip interface, respectively. This conclusion provides insightful guidance for altering the surface integrity of the machined surface based on needs.


2014 ◽  
Vol 800-801 ◽  
pp. 321-326 ◽  
Author(s):  
Bei Bei Wang ◽  
Li Jing Xie ◽  
Xi Bin Wang ◽  
Xiao Lei Chen

SiCp/Al composites (aluminum alloys reinforced with SiC particles) are classified as the typical difficult-to-machine materials by serious tool wear, premature tool failure, surface defects, etc. In order to understand the formation mechanism of chip and machined surface, the two-dimensional finite element modeling technology of the cutting process for SiCp/Al composites are investigated by using ABAQUS explicit. The actual microstructure is modeled by a multi-phase modeling approach with a circular SiC reinforcement phase randomly distributed in a 6061aluminum alloy matrix phase. The effect of volume fraction of SiC particles is studied by simulating the orthogonal cutting process of aluminum alloy and three SiCp/Al composites with multiplied increasing volume fraction of SiC reinforcement particles. The cutting forces vs. time due to the interaction between cutting tools and SiC particles in the cutting process and the stress distribution in three deformation zones are analyzed. Finally, surface defects including particles debonding, small pits, raised particles and traces of ploughing are predicted and verified by the experimental surface topography.


2020 ◽  
Vol 38 (12A) ◽  
pp. 1862-1870
Author(s):  
Safa M. Lafta ◽  
Maan A. Tawfiq

RS (residual stresses) represent the main role in the performance of structures and machined parts. The main objective of this paper is to investigate the effect of feed rate with constant cutting speed and depth of cut on residual stresses in orthogonal cutting, using Tungsten carbide cutting tools when machining AISI 316 in turning operation. AISI 316 stainless steel was selected in experiments since it is used in many important industries such as chemical, petrochemical industries, power generation, electrical engineering, food and beverage industry. Four feed rates were selected (0.228, 0.16, 0.08 and 0.065) mm/rev when cutting speed is constant 71 mm/min and depth of cutting 2 mm. The experimental results of residual stresses were (-15.75, 12.84, 64.9, 37.74) MPa and the numerical results of residual stresses were (-15, 12, 59, and 37) MPa. The best value of residual stresses is (-15.75 and -15) MPa when it is in a compressive way. The results showed that the percentage error between numerical by using (ABAQUS/ CAE ver. 2017) and experimental work measured by X-ray diffraction is range (2-15) %.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3432
Author(s):  
Edwin Gevorkyan ◽  
Mirosław Rucki ◽  
Tadeusz Sałaciński ◽  
Zbigniew Siemiątkowski ◽  
Volodymyr Nerubatskyi ◽  
...  

The paper presents results of investigations on the binderless nanostructured tungsten carbide (WC) cutting tools fabrication and performance. The scientific novelty includes the description of some regularities of the powder consolidation under electric current and the subsequent possibility to utilize them for practical use in the fabrication of cutting tools. The sintering process of WC nanopowder was performed with the electroconsolidation method, which is a modification of spark plasma sintering (SPS). Its advantages include low temperatures and short sintering time which allows retaining nanosize grains of ca. 70 nm, close to the original particle size of the starting powder. In respect to the application of the cutting tools, pure WC nanostructure resulted in a smaller cutting edge radius providing a higher quality of TiC/Fe machined surface. In the range of cutting speeds, vc = 15–40 m/min the durability of the inserts was 75% of that achieved by cubic boron nitride ones, and more than two times better than that of WC-Co cutting tools. In additional tests of machining 13CrMo4 material at an elevated cutting speed of vc = 100 m/min, binderless nWC inserts worked almost three times longer than WC-Co composites.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Xuefeng Zhao ◽  
Hao Qin ◽  
Zhiguo Feng

Tool edge preparation can improve the tool life, as well as cutting performance and machined surface quality, meeting the requirements of high-speed and high-efficiency cutting. In general, prepared tool edges could be divided into symmetric or asymmetric edges. In the present study, the cemented carbide tools were initially edge prepared through drag finishing. The simulation model of the carbide cemented tool milling steel was established through Deform software. Effects of edge form factor, spindle speed, feed per tooth, axial, and radial cutting depth on the cutting force, the tool wear, the cutting temperature, and the surface quality were investigated through the orthogonal cutting simulation. The simulated cutting force results were compared to the results obtained from the orthogonal milling experiment through the dynamometer Kistler, which verified the simulation model correctness. The obtained results provided a basis for edge preparation effect along with high-speed and high effective cutting machining comprehension.


2012 ◽  
Vol 19 (3) ◽  
pp. 347-358 ◽  
Author(s):  
Magdalena Vaverková ◽  
František Toman ◽  
Dana Adamcová ◽  
Jana Kotovicová

Study of the Biodegrability of Degradable/Biodegradable Plastic Material in a Controlled Composting EnvironmentThe objective of this study was to determine the degrability/biodegradability of disposable plastic bags available on the market that are labeled as degradable/biodegradable and those certified as compost. The investigated materials were obtained from chain stores in the Czech Republic and Poland. Seven kinds of bags (commercially available) were used in this study. One of them was a disposable bag made of HDPE and mixed with totally degradable plastic additive (TDPA additive). Another was a disposable made of polyethylene with the addition of pro-oxidant additive (d2w additive). One was labeled as 100% degradable within various periods of time, from three months up to three years, and four were certified as compostable. The test was carried out in a controlled composting environment. The biodisintegration degree of the obtained pieces was evaluated following a modified version of ČSN EN 14806 Norm "Packaging - Preliminary evaluation of the disintegration of the packaging materials under simulated composting conditions in a laboratory scale test" and a modified version of ČSN EN ISO 20200 "Plastics - Determination of the degree of disintegration of plastic materials under simulated composting conditions in laboratory-scale test" (ISO 20200:2004). The emphasis was put on determination whether the bags are degradable/biodegradable or not.


2013 ◽  
Vol 668 ◽  
pp. 616-620
Author(s):  
Shuai Huang ◽  
Huang Yuan

Computational simulations of indentations in elastic-plastic materials showed overestimate in determining elastic modulus using the Oliver & Pharr’s method. Deviations significantly increase with decreasing material hardening. Based on extensive finite element computations the correlation between elastic-plastic material property and indentation has been carried out. A modified method was introduced for estimating elastic modulus from dimensional analysis associated with indentation data. Experimental verifications confirm that the new method produces more accurate prediction of elastic modulus than the Oliver & Pharr’s method.


2021 ◽  
Vol 40 (1) ◽  
pp. 77-86
Author(s):  
Siwen Tang ◽  
Pengfei Liu ◽  
Zhen Su ◽  
Yu Lei ◽  
Qian Liu ◽  
...  

Abstract Al2O3 nano-scaled coating was prepared on micro-textured YT5 cemented carbide cutting tools by atomic layer deposition ALD. The effect of Al2O3 nano-scaled coating, with and without combined action of texture, on the cutting performance was studied by orthogonal cutting test. The results were compared with micro-textured cutting tool and YT5 cutting tool. They show that the micro-texture and nano-scaled Al2O3 coated on the micro-texture both can reduce the cutting force and friction coefficient of the tool, and the tools with nano-scaled Al2O3 coated on the micro-texture are more efficient. Furthermore, the friction coefficient of the 100 nm Al2O3-coated micro-texture tool is relatively low. When the distance of the micro-pits is 0.15 mm, the friction coefficient is lowest among the four kinds of pit textured nanometer coating tools. The friction coefficient is the lowest when the direction of the groove in strip textured nanometer coating tool is perpendicular to the main cutting edge. The main mechanism of the nanometer Al2O3 on the micro-textured tool to reduction in cutting force and the friction coefficient is discussed. These results show that the developed tools effectively decrease the cutting force and friction coefficient of tool–chip interface.


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