The Influence of Lubricant Viscosoty in Cold Work Forward Extrusion Using Micro–Pits Tool

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
A. Norhayati ◽  
S. Maizan ◽  
H.M. Zin ◽  
J. Y. Wira ◽  
W. B. Wan Nik ◽  
...  

The present research concerns on the study of the effects of micro–pits arrays formed on taper die using cold forward plane strain extrusion experiments. Each pit was of reverse pyramids configuration having 330 microns diagonal length. The pits were 860 microns apart each others. Two additive free paraffinic mineral oils with low viscosity (P2) and high viscosity (P3) were used in this experimental work. The experimental results were compared with the results obtained from the plane strain extrusion experimental works with taper die without micro–pits (NA). The experimental results focused on the extrusion load, billet surface roughness and billet grid pattern on inclination slope. From the results, the existence of the micro–pits array on the taper die surface affected the extrusion load. At the same time, the micro–pits array affected the extruded billet surface roughness after the experiments. From this experiment, we could conclude that the micro–pits formed on the taper die (PA) would control the frictional constraint on the taper die compared to those without the micro–pits (NA). However, high viscosity lubricant (P3) was found to cause more effects compared to low viscosity lubricant (P2).

2015 ◽  
Vol 74 (10) ◽  
Author(s):  
M. A. Nurul ◽  
S. Syahrullail ◽  
M. N. Musa

Lubrication is very important in metal forming processes to control wear and friction at the interface between interacting surfaces. Non-renewable resources, such as plain mineral oils are widely used due to its ability to act as a supplier to wearing contacts; it may function as a film material or even sustain chemical transformations to become a film material. Since non-renewable resources can only last for more than a decade, renewable resources have been studied in order to find alternative lubricants that can present similar results in terms of extrusion load and product quality. Two renewable lubricants were analyzed (RBD palm olein and jatropha) together with an additive free paraffinic mineral oil, VG32, which acted as a reference lubricant. The experiment used a cold work plane strain extrusion apparatus that consists of a pair of taper die and a symmetrical work piece (billet). The billet material was made of annealed pure aluminum JIS-A1100 with radius of 5 mm in the deformation area. It was found that higher viscosity lubricants produced low extrusion load and friction during metal forming process with no major severe wear on product quality. Based on the results, it was proven that renewable resource based lubricants can be considered as a substitute for common lubricants used in the industry, since they present similar results with those currently applied in the industry. 


2013 ◽  
Vol 594-595 ◽  
pp. 546-550 ◽  
Author(s):  
Mohd Jamir Mohd Ridzuan ◽  
Mohd Bin Sulaiman Hafis ◽  
K. Azduwin ◽  
A.R. Mohamed ◽  
S.N. Fitriah ◽  
...  

The study presented in this paper is focused on the effect of surfaces roughness of pure aluminium A1100 on the cold work extrusion process by three different angles of taper die. Different angles of taper die will affect the surface roughness of the workpiece. To protect the surface and to reduce friction, lubricants are often used in extrusion process [1]. Different lubricants may have different optimum taper die angle that are suitable to be applied. Two types of materials used in this experiment are steel SKD 11 for taper die and aluminium A1100 for workpiece and different angles applied are 30o, 45o, and 60o. Moreover, with respect to each angle, three different types of lubricants were used which are Daphne Draw S Series, Palm Olein, and EFB bio oil. The Universal Testing Machine and Surface Roughness Tester were used in this experiment. The result obtained from the experiment shows that at 30o of taper die angle were producing the smooth product surfaces for each lubricant and Daphne Draw S Series could reduce the surface roughness compared to other lubricant test.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5202
Author(s):  
Elizabeta Gjorgievska ◽  
Daniel S. Oh ◽  
Daewon Haam ◽  
Dragana Gabric ◽  
Nichola J. Coleman

A new category of commercial bulk fill composite resins (CRs) enables the placement of 4-mm-thick layers as an alternative to the traditional time-consuming incremental technique. The purpose of the present study was to compare the efficiency of the polymerization, adaptation and porosity of two high-viscosity ‘sculptable’ bulk fill CRs (Filtek™ Bulk Fill (3M™ ESPE, St. Paul, MN, USA) and Tetric EvoCeram® Bulk Fill (Ivoclar Vivadent AG, Schwan, Liechtenstein)) and two low-viscosity ‘flowable’ bulk fill CRs (SureFil® SDR™ flow (Dentsply Sirona, Charlotte, NC, USA) and Tetric EvoFlow® Bulk Fill (Ivoclar Vivadent AG, Schaan, Liechtenstein)). Cylindrical samples of the bulk fill CRs (4 mm height × 10 mm diameter) were analyzed by Fourier-transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Additionally, occlusal cavities were prepared in twelve extracted human molars and restored with the bulk fill CRs (n = 3 for each CR). The adaptation and porosity of the bulk fill CRs were evaluated by X-ray microcomputed tomography (µCT) with a 3D morphometric analysis, and the adaptation was also analyzed by scanning electron microscopy (SEM) on longitudinal vestibulo-oral sections of the restored teeth. The AFM analysis demonstrated that the surface roughness of the SureFil® SDR™ flow was higher than that of the Tetric EvoFlow® Bulk Fill and that the surface roughness of Filtek™ Bulk Fill was higher than that of Tetric EvoCeram® Bulk Fill. µCT and SEM confirmed that the flowable bulk fill CRs had excellent adaptation to the cavity walls. The 3D morphometric analysis showed the highest and lowest degrees of porosity in Filtek™ Bulk Fill and Tetric EvoFlow® Bulk Fill, respectively. In general, the flowable bulk fill CRs exhibited better adaptation, a higher efficiency of polymerization and lower porosity than the sculptable materials.


2020 ◽  
Vol 33 (2) ◽  
pp. 59-68
Author(s):  
Bruna Tavares ◽  
Fabiana França ◽  
Roberta Basting ◽  
Basting Turssi ◽  
Turssi Amaral

The aim of this in vitro study was to evaluate the effect of bleaching protocols on the surface roughness (Ra), color change and surface micromorphology of a low-viscosity bulk-fill composite (Filtek Bulk Fill Flow, 3M ESPE), a highviscosity bulk-fill composite (Filtek Bulk Fill, 3M ESPE) and a conventional nanoparticulate composite resin (control) (Filtek Z350 XT, 3M ESPE). Forty samples of each composite (disks 5 mm in diameter and 2 mm thick) were randomly divided into four groups (n=10), according to bleaching protocol: a) 10% carbamide peroxide gel (Opalescence, Ultradent Products) (2 h/ day, for 14 days); b) 40% hydrogen peroxide gel (Opalescence Boost, Ultradent Products) (three bleaching sessions, once a week, 45 min/session); c) whitening rinse (Listerine Whitening Extreme, Johnson & Johnson) (2 min/day, for 14 days); and d) distilled water (control). The samples were submitted to triplicate readings (Ra and color [CIELAB parameters]) before and after contact with bleaching protocols. Micromorphology was analyzed in a scanning electron microscope (SEM). Ra and color parameters (ΔL, Δa, Δb and ΔE) were analyzed by generalized linear models (α=0.05). The Ra of the high-viscosity bulk-fill was significantly higher than that of the other composites (p<0.05). Ra increased significantly (p<0.05) and surface became more irregular (SEM analysis) in all the composite resins, regardless of the bleaching protocol (p<0.05). The high-viscosity bulk-fill composite resin group had significantly lower ΔE (p<0.05) than the nanoparticulate composite resin group immersed in distilled water. It was concluded that the characteristics of each resin significantly influenced the Ra more than the bleaching protocol. The high-viscosity bulk-fill resin presented minor color change.


2019 ◽  
Vol 18 (5) ◽  
pp. 422-426
Author(s):  
I. S. Lugovaja

Hydraulic systems used in mechanisms and machines are intended for mechanical movements: load lifting, material pressing, moving of working bodies, etc. Mineral oils with low viscosity are used in them as working fluids. Such liquids include food products (honey, molasses, tar, minced meat, dough, pasta, creams, starches), construction materials (clay, cement, sealant), petroleum products, etc. which are found in chemical and textile, wine and bakery, cosmetic and confectionery, dairy and paintwork, construction industry and many other areas of activity. At the same time, hydraulic systems are used in various sectors of the national economy, which are designed for pumping or transporting a high-viscosity working fluid. However, description of such hydraulic systems, their classification, specific features of the devices of which they consist, has yet received insufficient attention. In this regard, this paper provides a classification of hydraulic systems for pumping and transporting highly viscous liquids, a description of their composition, main types of pumps and devices for controlling and performing technological tasks widely used in various industries. It is shown that all pumps used for these purposes can be divided into two groups: dynamic and volumetric. The paper presents schemes of devices, a brief description and operational principle of pumps used for these purposes. The executed analysis has shown that an operation of hydraulic systems for pumping highly viscous liquids necessitates further study of their characteristics, as well as development of methods for calculation and design.


2014 ◽  
Vol 554 ◽  
pp. 327-331 ◽  
Author(s):  
Samion Syahrullail ◽  
Mohd Ahyan Nurul Aini

In this paper, the effect of frictional constraint from the application of three different viscosity of additive free paraffinic mineral oil as lubricant were investigated by cold work forward plane strain extrusion experiments. The experiment used a cold work plane strain extrusion apparatus consist of a pair of taper die and a symmetrical workpiece (billet). The billet material was annealed pure aluminum A1100 with radius 5 mm in deformation area. The experimental result shows that the higher viscosity, will lead to lower friction effect to the deformed area, as well as product area.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 338
Author(s):  
Ali Alrahlah ◽  
Abdel-Basit Al-Odayni ◽  
Haifa Fahad Al-Mutairi ◽  
Bashaer Mousa Almousa ◽  
Faisal S. Alsubaie ◽  
...  

This study aimed to synthesize new bisphenol A-glycidyl methacrylate (BisGMA) derivatives, targeting a reduction in its viscosity by substituting one of its OH groups, the leading cause of its high viscosity, with a chlorine atom. Hence, this monochloro-BisGMA (mCl-BisGMA) monomer was synthesized by Appel reaction procedure, and its structure was confirmed using Fourier transform infrared spectroscopy, 1H and 13C-nuclear magnetic resonance spectroscopy, and mass spectroscopy. The viscosity of mCl-BisGMA (8.3 Pa·s) was measured under rheometry conditions, and it was found to be more than 65-fold lower than that of BisGMA (566.1 Pa·s) at 25 °C. For the assessment of the viscosity changes of model resins in the presence of mCl-BisGMA, a series of resin matrices, in which, besides BisGMA, 50 wt % was triethylene glycol dimethacrylate, were prepared and evaluated at 20, 25, and 35 °C. Thus, BisGMA was incrementally replaced by 25% mCl-BisGMA to obtain TBC0, TBC25, TBC50, TBC75, and TBC100 blends. The viscosity decreased with temperature, and the mCl-BisGMA content in the resin mixture increased. The substantial reduction in the viscosity value of mCl-BisGMA compared with that of BisGMA may imply its potential use as a dental resin matrix, either alone or in combination with traditional monomers. However, the various properties of mCl-BisGMA-containing matrices should be evaluated.


Aerospace ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Sicong Yu ◽  
Xufeng Zhang ◽  
Xiaoling Liu ◽  
Chris Rudd ◽  
Xiaosu Yi

In this concept-proof study, a preform-based RTM (Resin Transfer Molding) process is presented that is characterized by first pre-loading the solid curing agent onto the preform, and then injecting the liquid nonreactive resin with an intrinsically low viscosity into the mold to infiltrate and wet the pre-loaded preform. The separation of resin and hardener helped to process inherently high viscosity resins in a convenient way. Rosin-sourced, anhydrite-cured epoxies that would normally be regarded as unsuited to liquid composite molding, were thus processed. Rheological tests revealed that by separating the anhydrite curing agent from a formulated RTM resin system, the remaining epoxy liquid had its flowtime extended. C-scan and glass transition temperature tests showed that the preform pre-loaded with anhydrite was fully infiltrated and wetted by the liquid epoxy, and the two components were diffused and dissolved with each other, and finally, well reacted and cured. Composite laminates made via this approach exhibited roughly comparable quality and mechanical properties with prepreg controls via autoclave or compression molding, respectively. These findings were verified for both carbon and ramie fiber composites.


2014 ◽  
Vol 783-786 ◽  
pp. 2537-2540 ◽  
Author(s):  
Satoshi Sunada ◽  
Norio Nunomura ◽  
Sayaka Hirata ◽  
Naoki Nagase

Since Fe-Cu-C sintered steels are easily rusted, they are coated with rust preventive oils. High viscosity of those rust preventive oils decrease workability, and low viscosity deteriorates rust preventive performance. Therefore, it is necessary to develop new rust preventive oils with contradictory properties of low viscosity and superior rust prevention. However, precise methodology to evaluate rust prevention ability has not been established. In this study, we developed new technique to quantitatively evaluate rust prevention ability by measuring the open circuit potential through thin corrosive solution on Fe-Cu-C sintered steels coated with a rust preventive oils. As a result, the ability for rust prevention can be measured quantitatively, and it decreases slowly over time, with repeating destruction and restoration. Furthermore, it was found that the deteriorating processes of rust prevention ability for rust prevention oils are composed of three characteristics steps respectively. That is, in the first step the great open circuit potential changes from 0V to-0.3V with repetition were observed where the excellent rust prevention ability was kept, in the second step it decreases slowly from-0.1V to-0.4V with oscillation of the small potential changes where the gradual decrease of rust prevention ability was recognized and in the third step it decreases monotonously in the lower potential than-0.4V where the rust was observed because of the remarkable deteriorating of the rust prevention ability.


1995 ◽  
Vol 10 (8) ◽  
pp. 1984-1992 ◽  
Author(s):  
X.B. Zhou ◽  
J.Th.M. De Hosson

A this paper the influence of surface roughness on contact angles in the system of liquid Al wetting solid surfaces of Al2O3 has been studied. It was observed that contact angles of liquid Al vary significantly on different rough surfaces of Al2O3. A model is proposed to correlate contact angles with conventional roughness measurements and wavelengths by assuming a cosine profile of rough grooves with a Gaussian distribution of amplitudes. In comparison with the experimental results, the model provides a good estimate for describing the influence of surface roughness on contact angles of liquid Al on Al2O3.


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