scholarly journals Effect of the aging process at a temperature of 300 degrees Celsius of Ti6Al4V alloy on mechanical strength under static loading conditions

2019 ◽  
Vol 290 ◽  
pp. 08017
Author(s):  
Mateusz Wirwicki

Conventional construction of components is slowly being replaced by rapid prototyping and the use of DMLS technology. The development of DMLS requires conducting experimental studies that build a knowledge base that allows for the averaging of mechanical properties. verification of how the initiation of the crack occurs in the material and how the energy is propagated in the samples that were made by a conventional method compared to the samples, where the method of sintering titanium layers will be used. The literature analysis showed no research results relating to the impact of values of strength parameters on the structure of materials produced by the DMLS method. Titanium samples made with the additive method and the conventional titanium grade 5 Ti6Al4V titanium method, which is used, among others, in medicine, were used for the tests. The article presents the influence of material structure on mechanical properties (Re, Rm, A, Z). The presented research is preliminary research defining the properties of the material, which are gaining more and more application by using the DMLS method in the construction of machines and in medicine.

2015 ◽  
Vol 57 (4) ◽  
pp. 224-232
Author(s):  
Jarosław Siwiński ◽  
Katarzyna Kubiak ◽  
Miłosz Tkaczyk ◽  
Anna Mazur ◽  
Ryszard Rekucki

Abstract The study was conducted to perform a comparative analysis of the mechanical properties of wood samples derived from oaks in the Krotoszyn Plateau, which depend on the health state of the trees. Strength parameters of oak wood were calculated for selected diseased and healthy trees (according to the Roloff classification). The study was conducted by a modified method described in the standard Polish Norm PN EN 408+ A1: 2012. For testing, prior selection of wood samples showed that more wood samples of diseased trees compared with those of healthy oaks did not fulfil the Polish standard requirements. According to the method used, the average results of strength tests of timber structures from healthy oaks exhibited higher strength parameters than those of the diseased trees.


2017 ◽  
Vol 62 (2) ◽  
pp. 483-487 ◽  
Author(s):  
M. Suliga ◽  
R. Wartacz ◽  
J. Michalczyk

Abstract The paper contains the theoretical and experimental analysis of the impact of the drawing angle on the drawing process and the properties of low carbon steel wires. A multi-stage drawing wire rod with a diameter of 5.5 mm on a wire with a diameter of 1.0 mm has been carried out in two stages. The first one consisted of preliminary drawing wire rod for the wire with a diameter of 2.2 mm which was next subjected to the drawing process at a speed of 25 m/sec at the final wire with a diameter of 1.0 mm. The wires were drawn in conventional dies with drawing angle α = 3, 4, 5, 6, 7 degrees. For the wires drawn in respective variants, the investigation of the mechanical properties was performed and the amount of lubricant on the surface of steel wires was determined. Numerical analysis of the process of drawing in the Drawing 2D complemented the experimental studies. It has been shown that when drawing at high speeds, properly chosen the value of the angle of the working part of the die can improve the lubrication conditions and mechanical properties of steel wires.


2014 ◽  
Vol 33 (6) ◽  
pp. 585-591 ◽  
Author(s):  
Shi Liu ◽  
Jinyu Xu

AbstractConducting experimental studies on the impact compressive mechanical properties of rock under the high temperature environment is of both theoretical value and practical significance to understanding the relationship between the rock under the effect of impact loads and the high temperature environment. Based on the Φ100 mm SHPB and the self-developed Φ100 mm high-temperature SHPB test devices, the impact compressive tests on the sandstone, whether cooling after high temperatures or under real-time high temperatures are carried out. As the test results indicate that since the two high-temperature ways of loading are different from each other, the impact compressive properties of sandstone, after as well as under high temperatures, show different variations along with changes in temperature. Under the effect of the same impact loading rate, there exists a clear critical temperature range in the impact compressive mechanical properties of sandstone after high temperature, and, near the critical temperature, there occurs a significant mutation in the impact compressive mechanical properties. Under high temperatures, however, the impact compressive mechanical properties follow an overall continuity of change except that there are slight fluctuations at individual temperatures.


2021 ◽  
Vol 2021 (11) ◽  
pp. 51-59
Author(s):  
Nikolay Kurnosov ◽  
Aleksandr Tarnopol'skiy ◽  
Yuliya Nakashidze

Work objective is to solve the urgent problem of increasing the tightness and reliability of pressure couplings during their operation under dynamic loads. Theoretical and experimental studies assessing the impact on the tightness due to roughness nature of mating surfaces and three types of coatings: soft, double-layer and hard have been undertaken. The joints were tested under the influence of axial cyclic load and torque on a bench for accelerated testing. It is established that tightness of pressure couplings during operation under dynamic loads significantly depends on the parameters of microgeometry and physical and mechanical properties of the mating surface material that determine their actual contact area. Recommendations for preparing the surfaces of parts before pressure coupling assembling have been developed. It is proved that the use of regular microrelief and soft galvanic coatings of mating surfaces have a significant effect on the tightness of pressure couplings.


Cellulose ◽  
2021 ◽  
Author(s):  
Piotr Pospiech ◽  
Konrad Olejnik ◽  
Urszula Mizerska ◽  
Joanna Zakrzewska

Abstract The aim of the study was to investigate the impact of three types of polysiloxane microspheres on the barrier properties, structure and mechanical properties of paper. An influence of new silicon filler on properties of cellulose paper sheet was analyzed. Polysiloxane microspheres were used as an additive introduced into the network of cellulosic fibers in order to obtain new functional properties of the paper. The following types of microspheres were used in the research: M1 hydrophilic of average diameter 23.5 µm, M2 hydrophobic of average diameter 3.1 µm and M3 hydrophobic of average diameter 23.5 µm. The obtained handsheets were analyzed for changes in apparent density, roughness, tensile strength, bursting strength, and tear resistance. Wettability and resistance to liquid were characterized by contact angle measurement, penetration dynamics analysis  and uniformity of liquid penetration measured using an extended liquid penetration analyser. It was found that the presence of M2 (small diameter) microspheres improved significantly the paper’s hydrophobicity without changing the mechanical properties. The addition of M1 and M3 (large diameter) microspheres decreased the mechanical properties of the paper samples and did not improve their hydrophobicity. However, M1 microspheres resulted in increased uniformity of liquid penetration through the paper structure. The presented studies also show that it is possible to obtain paper with high hydrophobic properties only through the filling application when polysiloxane microspheres are used for this purpose. The results also indicate that it is not necessary to hydrophobize the entire material structure in order to achieve its high hydrophobicity. Graphic abstract


2021 ◽  
Vol 244 ◽  
pp. 04007
Author(s):  
Nikolay Plotnikov ◽  
Olga Burova

The purpose of the conducted experimental studies is to examine the effect of various influences on the object of study. These effects are called factors. Some of them vary while examining of the object and then they are called variable factors. Each factor takes one or more values in the experiment and then they are called factor levels. The set of values of this factor is called range of factor values – the smallest interval, where are all the values accepted by this factor in the experiment. According to GOST 19222-84, the dependence of the physical-mechanical characteristics of sawdust slag concrete (grade M10) on the specific gravity (share) of wet sawdust of coniferous species and ash-slag mixture in the composition was studied. Regression analysis was used to build a mathematical model of the process with quantitative factors, to verify its adequacy, and to assess the impact of each variable factor on the process. To obtain regression dependencies, a composite second-order B-plan was implemented.


2021 ◽  
Vol 264 ◽  
pp. 02010
Author(s):  
Abdubaki Kayumov ◽  
Rashidbek Hudaykulov ◽  
Dilfuza Makhmudova ◽  
Dilshod Kayumov

The constant development of the road network in Uzbekistan, especially in widespread saline soils, necessitates increased attention to road structure strength. Since vehicles differ in weight and speed, it is obvious that the saline soil under the pavement is subjected to successive impacts of a load of different power and application force. Experimental studies to identify the patterns of changes in saline soils' physical and mechanical properties under repeated and short-term loads were conducted on a device specially designed by the authors of this study. The experiments were conducted on samples of sulfate and chloride-sulfate medium-saline heavy silty sandy loam, compacted at optimal moisture content to maximum density. When conducting the experiment, the impact duration of vertical load Рver = 0.15 MPa on the sample was tload = 0.2 sec, and the interval between the loads was 0.5 sec, the frequency of application was f = 1.2 Hz. The number of short-term load applications was recorded using an electric meter installed on the device. After a certain number of short-term cyclic load applications on the sample, its physical and mechanical properties were determined following the requirements of state standards (GOST). The results of the study show that with an increase in the number of cyclic and short-term load impacts on the sample, the following values increase: residual strain, density, and modulus of setting, relative swelling, swelling pressure, ultrasonic transmission rate, coefficient of filtration; while the porosity, coefficient of porosity, soaking, ultimate strength in uniaxial compression, the coefficient of dynamic viscosity, adherence, the angle of internal friction and the modulus of elasticity of soil decrease. It was determined that under the repeated impact of short-term loads in compacted saline soil, residual strains and short-term redistribution of stresses in the contact of soil and salt particles occur, which leads to a change in the physical and mechanical properties of soil.


2020 ◽  
Vol 128 ◽  
pp. 81-88 ◽  
Author(s):  
Paweł Kowalik ◽  
Mariusz Fabijański

The purpose of this study is to present the requirements, methodology, and results of research on the impact of biodegradable oil on plastic components used in the construction of a railway turnout. Briefly discussed are what railroad turnouts are, how they work, and what problems occur with substances used for their lubrication. They have an impact on the mechanical properties and durability of products made of polymeric materials. These types of materials absorb various kinds of chemicals, to a greater or lesser degree, and this affects their properties. For the tests, we used a universal lubrication oil with biodegradable properties, which is its most significant advantage. However, it may not cause deterioration of the turnout operation and change the properties of materials used for its construction. These types of oils require more frequent applications on cooperating components. We used the two most popular polymer materials. The first is high-density polyethylene (HDPE), used to make all kinds of rail spacers, dowels for fixing rails, sleeves, etc. The second, polyurethane (PUR) is most commonly used for rail pads of various shapes. The methodology and results of testing the impact of a lubricant (biodegradable oil) on the change of mechanical properties such as strength and hardness are presented. The tests were carried out at various temperatures; the time of exposure to oil was seven days; the results were referred to samples conditioned under standard conditions. The tests carried out on the impact of the biodegradable lubricant on polymeric materials (HDPE and PUR) showed little effect on the change of strength parameters of these materials. Celem niniejszego opracowania jest przedstawienie wymagań, metodyki oraz wyników badań oddziałania biodegradowalnego oleju na elementy z tworzyw sztucznych stosownych w budo-wie rozjazdu kolejowego. Krótko omówiono czym są rozjazdy kolejowe i jak działają oraz jakie występują problemy z substancjami używanymi do ich smarowania, które nie pozostają bez wpływu na właściwości mechaniczne i trwałość wyrobów z materiałów polimerowych. Materiały tego typu wchłaniają różnego rodzaju substancje chemiczne w większym lub mniejszym stopniu, a to ma wpływ na ich właściwości. Do badań został wykorzystany uniwersalny olej do smarowania o biodegradowalnych właściwościach, co jest jego największą zaletą. Jednak nie może on powodować pogorszenia pracy rozjazdu oraz zmieniać właściwości materiałów użytych do jego budowy. Tego typu oleje wymagają częstszego aplikowania na elementy współpracujące ze sobą. W pracy wykorzystano dwa najbardziej popularne materiały polimerowe. Pierw-szy to polietylen o dużej gęstości (HDPE), z którego wykonuje się wszelkiego rodzaju przekładki podszynowe, dyble do mocowania szyn, tuleje, itp. Drugi to poliuretan (PUR) stosowany najczęściej na przekładki podszynowe o różnym kształcie. Zaprezentowano metodykę i wyniki ba-dań oddziaływania środka smarnego (biodegradowalnego oleju) na zmianę właściwości mechanicznych takich jak wytrzymałość oraz twardość. Badania zostały przeprowadzone w różnych temperaturach, a czas ekspozycji na olej wynosił 7 dób, wyniki odniesiono do próbek klimatyzowanych w standardowych warunkach. Przeprowadzone badania oddziaływania biodegradowalnego środka smarnego na tworzywa polimerowe (HDPE i PUR), wykazały niewielki wpływ na zmianę parametrów wytrzymałościowych tych materiałów.


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