SURFACE ROUGHNESS IMPROVEMENT OF PARTS MADE OF POLYMERIC MATERIALS OBTAINED BY MEANS OF ADDITIVE TECHNOLOGIES

2021 ◽  
Vol 2021 (7) ◽  
pp. 12-18
Author(s):  
Mikhail Kulikov ◽  
Maksim Larionov ◽  
Denis Gusev ◽  
Evgeniy Shevchuk
Keyword(s):  
Surface Quality ◽  
Polymeric Materials ◽  
Additive Technologies ◽  
Abrasive Tool ◽  
Technological Basis ◽  
Dry Processing ◽  
Investigation Methods ◽  
Before And After ◽  
Part Surface ◽  
Surface Layer Quality

In the paper there is under consideration an effort to achieve the roughness index of Ra <0.8 with the aid of soft abrasive tool use. As a result the purpose of this work became development of the technology for surface quality improvement of parts manufactured with the aid of additive technologies. The authors carried out a number of experiments with the samples manufactured with the aid of the method of FDM print. With the aid of 3D Ultra 3 printer of EnvisionTec company. The samples were made of ABS-plastic in the amount of 6 pieces. On each sample there were defects after printing which contributed to the deterioration of surface quality in products. By means of TR220 profilometer there was measured roughness before and after the experiment. There was carried out dry processing and with the use of SCL. As a result, dry processing resulted in worsening surface quality, heavy wear of an abrasive tool and grain contamination. Analyzing the data obtained from the profilometer in the experiment and SCL use a considerable improvement of the surface layer quality at minimum allowance is observed. Investigation methods: in the work basis there are experimental methods of investigation. The investigations are carried out with the use of a microscope and profilometer. Processing investigation results was carried out as a result of the comparison of the measuring data obtained. Work Novelty: there are defined conditions of soft abrasive tool operation and SCL impact upon Ra indices. The results obtained indicate a possibility of Ra improvement on a part surface which is achieved due to a combined shaping with the aid of additive technologies and further machining carried out on a single technological basis. The experience without SCL use has shown the overheating possibility the result of which is a meltback and plastic sticking both on the surface, and on abrasive grains of the cutter which is inadmissible and results in considerable worsening of Ra on the surface machined and cutter wear. In view of this the SCL use in finishing is promising, but to achieve better results SCL chemistry must be improved.

INVESTIGATION OF COMBINED METHOD USE FOR COPPER AND ALUMINUM ALLOY PROCESSING

2020 ◽  
Vol 2020 (11) ◽  
pp. 26-35
Author(s):  
Vitaliy Inozemtsev
Keyword(s):  
Surface Layer ◽  
Aluminum Alloy ◽  
Surface Quality ◽  
Statistical Processing ◽  
Combined Method ◽  
Friction Forces ◽  
Investigation Methods ◽  
Definition Of ◽  
Surface Layer Quality ◽  
Complex Methods

The work purpose: the investigation of obtaining by a surface the required properties and possibility degree to control shaping processes. It is well-known that a shaping process is affected by many factors particularly at complex methods of processing. The analysis of machining condition impact upon surface layer quality of parts allows defining optimum parameters of cutting and increasing parts operation characteristics. Investigation methods: theory, experimental researches, statistical processing of results, mathematical modeling, analysis. Research results: there are defined criteria of surface quality at complex methods of shaping, roles of factors included in processing, mathematical models are formed, recommendations are formulated. Novelty: it consists in the definition of regularities in pore covering at metal ceramic finish machining and definition of processing conditions impact upon pore covering, and also in the definition of efficient conditions of aluminum alloy finishing at the combined method of shaping. Conclusions: as the investigations carried out show the combined methods of impact upon a surface at parts shaping allow reducing also cutter wear, minimizing collateral processing factors connected with heat generation, with increased friction forces and surface layer deformation of a billet at its processing. The combination of machining with electro-chemical processing allows not only having an influence considerable upon surface quality increase, but decreasing technological residual stresses and also contributing to the restoration of mechanical and physical properties of metal surfaces after electro-erosion processing at the expense of surface micro-layer elimination with the acquired thermal changes of structures.

scholarly journals Study of the Ultraviolet Effect and Thermal Analysis on Polypropylene Nonwoven Geotextile

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  
Keyword(s):  
Uv Light ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Material Stiffness ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Physical Tests ◽  
Nonwoven Geotextile

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.

Evaluation of Process Wear of Selected Tool Steels for Injection Molds

2013 ◽  
Vol 739 ◽  
pp. 171-176 ◽  
Author(s):  
František Greškovič ◽  
Ľudmila Dulebová ◽  
Branislav Duleba ◽  
Janusz W. Sikora
Keyword(s):  
Adhesive Wear ◽  
Glass Fibers ◽  
Polymeric Materials ◽  
Tool Steels ◽  
Screw Extruder ◽  
Laboratory Equipment ◽  
Before And After ◽  
Twin Screw ◽  
Weight Decrease ◽  
Short Glass

The aim of this contribution is to test the suitability of selected types of tool steels used for manufacturing of injection molds. Experiments were realized by the simulation of adhesive wear using laboratory equipment Amsler, which allows the testing of grinding pairs. Evaluated grinding pairs consisted of tool steel and two types of roundels. Tested polymeric materials were based on pure PA6 and PBT filled with short glass fibers, prepared by mixing process in twin screw extruder. The wear of five types of tool steels were evaluated by weight decrease before and after the experiment, while changing the friction coefficient of grinding pairs, material of grinding pairs and sensing the roughness of steel before and after wear.

Feed fluctuation of ball screw feed systems and its effects on part surface quality

2016 ◽  
Vol 101 ◽  
pp. 1-9 ◽  
Author(s):  
Tao Liang ◽  
Dun Lu ◽  
Xiaojun Yang ◽  
Jun Zhang ◽  
Xiaobo Ma ◽  
...  
Keyword(s):  
Surface Quality ◽  
Ball Screw ◽  
Part Surface ◽  
Screw Feed

The Research of NURBS Curve Interpolation Algorithm Based on Parabolic and the First-Order Taylor Expansion Interpolation Algorithm

2014 ◽  
Vol 1003 ◽  
pp. 260-263
Author(s):  
Zhi Qiang Zhang ◽  
Wen Jin Wang ◽  
Jing Zhang ◽  
Jian Zhao ◽  
Li Ying Sun ◽  
...  
Keyword(s):  
Surface Quality ◽  
Taylor Expansion ◽  
Interpolation Error ◽  
Interpolation Algorithm ◽  
Nurbs Curve ◽  
First Order ◽  
Parabolic Interpolation ◽  
Curve Interpolation ◽  
Part Surface ◽  
Current Point

The NURBS curve interpolation algorithm based on parabolic interpolation error and the first-order Taylor expansion interpolation algorithm is proposed to improve part surface quality and chord error of NURBS curve interpolation algorithm. The part surface quality is improved effectively by the parabolic interpolation algorithm in the conduction that the previous point, the current point and the next point which was computed by the first order Taylor expansion interpolation algorithm were known. The effectiveness of this algorithm is proved by the NURBS curve interpolation simulation.

Tribological Characteristics of DLC-Coated Alumina at High Temperatures

2006 ◽  
Vol 128 (4) ◽  
pp. 711-717 ◽  
Author(s):  
K. Y. Lee ◽  
R. Wei
Keyword(s):  
High Temperature ◽  
Morphological Changes ◽  
Extreme Environments ◽  
Polymeric Materials ◽  
Film Coating ◽  
Wide Range ◽  
Before And After ◽  
Modification Technique ◽  
Increasing Demand ◽  
Coated Surfaces

Ceramic seals are widely used in many severe applications such as in corrosive, high temperature and highly loaded situations especially in hot chemical water-based extreme environments for automobile water pumps. Presently, polymeric materials are used as the counter part for alumina ceramic seals to reduce the ceramic-to-ceramic wear. As a result, leaks are very commonly observed from water pump during services. Consequently, it is needed to improve the surface properties of the ceramic seals using a surface modification technique such as a thin film coating process to meet the increasing demand of more stability, more durability, and lower friction of coefficient in those extreme environments. To meet these challenges, we have applied DLC (diamond-like carbon) coatings on alumina using a PIID (plasma immersion ion deposition) technique intended for seal applications. The DLC-coated specimens were tested under a wide range of temperature conditions, from room temperature up to 400°C, using a high temperature pin-on-disk tribo-tester. After that, the wear-tested specimens were analyzed using SEM with EDS to characterize the worn surfaces. Morphological changes of the DLC coated surfaces before and after the wear tests were studied. Under certain deposition conditions DLC performed very well up to 400°C. However, under other conditions, DLC failed catastrophically. In this paper we will present the friction and wear characteristics of the DLC-coated alumina. Finally, we will discuss the failure mode of DLC coatings.

scholarly journals Optimization of Wastewater Treatment Process on Energy Costs at Truck and Tractor Washing Posts

2019 ◽  
Vol 18 (5) ◽  
pp. 436-442
Author(s):  
A. V. Krutau ◽  
M. M. Dechko ◽  
M. A. Boika
Keyword(s):  
Current Density ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Water Disinfection ◽  
Energy Costs ◽  
Laboratory Unit ◽  
Wastewater Treatment Process ◽  
Investigation Methods ◽  
Before And After ◽  
Degree Of Purification

The paper considers a process pertaining to purification of oily effluents while using electrocoagulation, electro-flotation and an electromagnetic hydro-cyclone, implemented with the help of a laboratory unit (Patent of the Republic of Belarus for the invention No 21229). The investigations have been carried out with the purpose to optimize specific energy consumption for the process of cleaning fuel and lubricants effluents. The following investigation methods have been applied – a literature review, a comparative analysis, an experiment execution, a mathematical modeling. Content of oil products in wastewater before and after treatment has been evaluated in the analytical laboratory of the Belarusian State Agrarian Technical University in accordance with standard methods. Purification of the oily effluents has been made with the help of a laboratory unit while using electroflotocoagulation method with removal of floated sludge in an electromagnetic hydrocyclone. This cleaning method makes it possible to increase a degree of water disinfection, provides a closed water supply, rational use of water resources, reduction of harmful effects of pollutants on the environment. An experimental design technique has been worked out and a three-level Box – Behnken design has been implemented in the paper. The problem concerning optimization of the purification process on energy costs has been solved without worsening the required concentration indices of petroleum products in water after treatment . Mathematical models have been obtained and optimal purification modes have been determined at the lowest specific energy costs and with sufficiently high degree of purification. Significance of regression coefficients has been estimated by Student criterion. It has been established that while using the proposed unit it is possible to obtain a degree of wastewater purification at automotive equipment washing stations with its performance G = 0.7 l/s, current density j = 150 A/m2. The degree of purification, determined by ratio of pollutant concentrations before and after purification, is up to 99.9 %. The results can be used in implementation of microprocessor control of cleaning mode while taking an initial concentration of pollution, unit capability, current density of an electroflotocoagulator as control action factors.

Wire Vibration Modeling and Experimental Analysis for Wire Saw Machining

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Aofei Tang ◽  
Shujuan Li ◽  
Guigeng Yang ◽  
Lun Li ◽  
Robert G. Landers
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Feed Rate ◽  
Processing Time ◽  
Experimental Studies ◽  
Wire Tension ◽  
Wire Saw ◽  
Part Surface ◽  
Wire Vibration ◽  
The Wire

Abstract Surface roughness is the key index point of wire saw processing silicon carbide (SiC). Many factors influence wafer surface quality, which is determined by the motion of the wire relative to the part. The vibration characteristic of wire saw and the process parameters are concerned factors in this paper, which presents a wire vibration model to study the wire saw vibration law. Experimental studies of a stationary wire are conducted to calibrate the damping coefficient and experimental studies of a moving wire are used to validate the developed model. Simulation, theoretical, and experimental data for wire vibrations during a variety of machining processes are found to compare very well, and the effects of various wire saw process parameters are investigated to analyze the influences of process parameters on wire vibration. It was shown that increasing the wire tension and feed rate, or decreeing the wire length, decreases the wire's first dominant frequency, and that changes in the wire velocity had a negligible effect. Finally, the measurement of the surface morphology and wire saw vibrations for different processing parameters was conducted, and it was seen that increases in the wire velocity and wire tension increases part surface quality and decreases processing time, while an increase in the feed rate decreases both part surface quality and processing time. The results show a clear correlation between the amplitude of the wire vibration outside of the processing zone and the part surface quality.

Preparation of parts for coating by granular abrasive media treatment

2020 ◽  
pp. 416-419
Author(s):  
M.A. Tamarkin ◽  
E.E. Tishchenko ◽  
V.M. Troitsky ◽  
A.A. Mordovtsev
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Processing Time ◽  
Quality Parameters ◽  
Technological Operation ◽  
Design Technique ◽  
Part Surface ◽  
Medium Particle

The formation of surface quality parameters of parts treated in granular abrasive media, on the surface of which it is necessary to apply coatings is study. Parameters of trace are determined during interaction of medium particle with part surface. Dependencies for calculating of surface roughness and processing time are established. The design technique of technological operation for preparation of part for coating is described.

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