scholarly journals Machinability of the Thermoplastic Polymers: PEEK, PI, and PMMA

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 69
Author(s):  
Ying Yan ◽  
Yu Mao ◽  
Bo Li ◽  
Ping Zhou

The thermoplastic polymer such as poly(methyl methacrylate) (PMMA), polyetheretherketone (PEEK), and polyimide (PI) is a kind of polymer material with properties of good mechanical strength. It has been widely used in the fields of aerospace, optical engineering, and microfluidics, etc. Thermoplastic polymers are considered to be one of the most promising engineering plastics in the future. Therefore, it is necessary to further study its mechanical properties and machinability, especially in ultra-precision machining. Furthermore, mechanical property and machinability were studied in this work. Through the dynamic mechanical analysis experiment, the elastic modulus and temperature effect of PMMA, PEEK, and PI are analyzed. In addition, the high-speed micromilling experiment is conducted to show that the surface roughness, burrs, and cutting chip characteristics in the high-speed micromilling process. In general, the surface quality of the brittle removal is generally better than that of the viscoelasticity state. The results show that PMMA, PEEK, and PI have good mechanical properties and machinability. Base on the results, the material will be in a viscoelastic state as the temperature increases. The surface quality of the brittle removal is generally better than the viscoelastic state.

2009 ◽  
Vol 69-70 ◽  
pp. 253-257
Author(s):  
Ping Zhao ◽  
Jia Jie Chen ◽  
Fan Yang ◽  
K.F. Tang ◽  
Ju Long Yuan ◽  
...  

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.


Author(s):  
Nguyen Duy Canh ◽  
Nguyen Van Canh ◽  
Pham Xuan Hong ◽  
Nguyen Ngoc Hue ◽  
Tran Dinh Duy

2017 ◽  
Vol 54 (3) ◽  
pp. 543-545 ◽  
Author(s):  
Yusrina Mat Daud ◽  
Kamarudin Hussin ◽  
Azlin Fazlina Osman ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
...  

Preparation epoxy based hybrid composites were involved kaolin geopolymer filler, organo-montmorillonite at 3phr by using high speed mechanical stirrer. A mechanical behaviour of neat epoxy, epoxy/organo-montmorillonite and its hybrid composites containing 1-8phr kaolin geopolymer filler was studied upon cyclic deformation (three-point flexion mode) as the temperature is varies. The analysis was determined by dynamic mechanical analysis (DMA) at frequency of 1.0Hz. The results then expressed in storage modulus (E�), loss modulus (E�) and damping factor (tan d) as function of temperature from 40 oC to 130oC. Overall results indicated that E�, E�� and Tg increased considerably by incorporating optimum 1phr kaolin geopolymer in epoxy organo-montmorillonite hybrid composites.


Author(s):  
Hongji Zhang ◽  
Yuanyuan Ge ◽  
Hong Tang ◽  
Yaoyao Shi ◽  
Zengsheng Li

Within the scope of high speed milling process parameters, analyzed and discussed the effects of spindle speed, feed rate, milling depth and milling width on milling forces in the process of high speed milling of AM50A magnesium alloy. At the same time, the influence of milling parameters on the surface roughness of AM50A magnesium alloy has been revealed by means of the measurement of surface roughness and surface micro topography. High speed milling experiments of AM50A magnesium alloy were carried out by factorial design. Form the analysis of experimental results, The milling parameters, which have significant influence on milling force in high speed milling of AM50A magnesium alloy, are milling depth, milling width and feed speed, and the nonlinear characteristics of milling force and milling parameters. The milling force decreases with the increase of spindle in the given mill parameters. For the effects of milling parameters on surface quality of the performance, in the milling depth and feeding speed under certain conditions with the spindle speed increases the surface quality of AM50A magnesium alloy becomes better with the feed speed increases the surface quality becomes poor. When the spindle speed is greater than 12000r/min, the milling depth is less than 0.2mm, and the feed speed is less than 400mm/min, the milling surface quality can be obtained easily.


2012 ◽  
Vol 560-561 ◽  
pp. 655-660
Author(s):  
Li Juan Li ◽  
Li Hua Liu ◽  
Jing Wang

In order to guide atmosphere annealing process in industry, the effect of atmosphere and holding times on the surface quality and mechanical properties of the cold-rolling plate of Fe-42% Ni (4J42) was studied. It is found that in the laboratory, surface qualities of all the samples annealed at different annealing condition are all good enough. When the ratio of hydrogen and nitrogen is below 70%:30%, at different holding time, with increasing of H2 proportion, 4J42’s tensile strength and yield strength all increases, and the hardness declines. And except H2:N2=70%:30, when holding time is less than or equal to 1.2min, at different ratio of hydrogen and nitrogen, holding time will influence 4J42’s mechanical properties little. So combine requires in industry with the experiment results, it can be concluded that for 4J42 alloy, annealing at atmosphere of hydrogen nitrogen ratio is less than 70%:30% for about 1.2min is appropriate to atmosphere annealing process in industry.


Author(s):  
Yuanxin Zhou ◽  
Peixuan Wu ◽  
Zhongyang Cheng ◽  
Biddut Kanti Dey ◽  
Shaik Jeelani

In this study, electrical, thermal and mechanical properties of multi-walled carbon nanotubes (CNTs) reinforced Epon 862 epoxy have been evaluated. Firstly, 0.1 wt%, 0.2 wt%, 0.3 wt%, and 0.4 wt% CNT were infused into epoxy through a high intensity ultrasonic liquid processor and then mixed with EpiCure curing agent W using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. Neat epoxy sample also was made as reference. Electrical conductivity, dynamic mechanical analysis (DMA, three point bending tests and fracture tests were performed on unfilled, CNT-filled epoxy to identify the loading effect on the properties of composites. Experimental results show significant improvement in electric conductivity. The resistivity of epoxy decreased to 15Ωm with 0.4% CNT. DMA studies revealed that filling the carbon nanotube into epoxy can produce a 90% enhancement in storage modulus and a 17° C increase in Tg, but CNT has little effect on decomposing temperature. Mechanical test results showed that modulus increased with higher CNT loading percentages, but the 0.3 wt% CNT-infusion system showed the maximum strength and fracture toughness enhancement. The decrease in strength and fracture toughness in 0.4% CNT/epoxy was attributed to poor dispersions of nanotubes in the composite.


2014 ◽  
Vol 657 ◽  
pp. 18-22 ◽  
Author(s):  
Bogdan Chirita ◽  
Nicolae Catalin Tampu

Magnesium alloys exhibit a very good ratio of mechanical properties versus specific weight, thus making it an important choice for parts used in automotive, aeronautic and medical industry. The distribution of residual stress in the superficial layer of the material is regarded as one of the factors defining the surface quality of a machined part. It is therefore important to know this distribution as it is closely related to fatigue and corrosion resistance, especially for the parts working in aggressive environments (i.e. biomedical devices). The present paper focuses on the determination of the residual stresses induced in a magnesium alloy part processed by milling, and their effects on surface quality.


2014 ◽  
Vol 1077 ◽  
pp. 61-65
Author(s):  
Pei Yan ◽  
Xiang Su ◽  
Gang Wang ◽  
Yi Ming Rong

As the development of new materials and high speed machining, cutting fluid becomes more and more important because of its functions of cooling, lubrication, corrosion protection and cleaning. The main purposes of cutting fluid are decreasing temperature, reducing friction, extending tool life and improving machining efficiency. In precision machining, high machined surface integrity is the most important. In this paper, a preliminary experimental study on effect of two different cutting fluids on milled surface quality of iron-base superalloy was taken. The surface morphology, roughness, micro hardness and residual stress of the machined surface were investigated. The results showed that the material properties and geometric characteristics of the machined surface were significantly affected by cutting fluid conditions. The effect of cutting fluid on machined surface quality and service performance will become an important research direction. This paper also suggests the main contents of the further research on effect of cutting fluids on machined surface.


Author(s):  
Md. Atiqur Bhuiyan ◽  
Mahesh V. Hosur ◽  
Yaseen Farooq ◽  
Shaik Jeelani

In this study, thermal and mechanical properties of carbon nanofiber infused polyurethane foam were investigated. Low density liquid polyurethane foam composed of Diphenylmethane Diisocyanate (Part A) and Polyol (Part B) was doped with carbon nanofibers (CNF). A high-intensity ultrasonic liquid processor was used to obtain a homogeneous mixture of Diphenylmethane Diisocyanate (Part A) and carbon nanofibers (CNF). The CNF were infused into the Part A of the polyurethane foam through sonic cavitation. The modified foams containing nanoparticles were mixed with Part B (Polyol) using a high-speed mechanical agitator. The mixture was then cast into pre-heated rectangular aluminum molds to form the nano-phased foam panels. Flexure, static and high strain rate compression, and dynamic mechanical analysis (DMA) were performed on neat, 0.2 wt%, 0.4 wt% and 0.6 wt% CNF filled polyurethane foam to identify the effect of adding CNF on the thermal and mechanical properties. The highest improvement on thermal and mechanical properties was obtained with 0.2 wt% loading of CNF. Morphology of the samples was studied through X-ray diffraction.


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