Set Of Mechanical Properties Research Articles

STUDY OF THE SEAMLESS PIPES PROPERTIES OBTAINED FROM A HOLLOW BILLET

The article researched the influence on the pipes mechanical properties initial billet obtained by the traditional method and the proposed method, in which the piercing process is excluded. The proposed method involves casting the initial billet for the production of seamless pipes with a cavity obtained on a continuous casting machine. The production of hotrolled seamless pipes from a hollow billet is an urgent issue today, since central porosity and axial segregation after casting are excluded, affecting the quality of the pipes obtained in the subsequent stages of production: rolling on a mandrel mill and reducing. The possibility of producing seamless hot-rolled pipes from a hollow billet is substantiated, providing the necessary set of mechanical properties that are regulated by the standards GOST 632-80, GOST 633-80 and API 5CT. The result is a minimal deviation of the mechanical properties of steel samples obtained by double deformation of a hollow continuously cast billet from samples obtained according to the traditional scheme, including the piercing process. Keywords: hollow billet, steel, 09Mn2Si, seamless pipe, piercing process.

Properties of silicon dioxide coatings obtained by nano physical vapor deposition (PVD) method on the titanium 13‐niobium 13‐zirconium alloy

AbstractSurface modification techniques play an important role in adjusting the physicochemical properties of titanium and its alloys. To reduce the penetration of alloying element ions into the body, various types of oxide coatings are used to protect it from the corrosive environment. Another important issue related to the surface layer requirement is ensuring an appropriate set of mechanical properties. Accordingly, in this study, the mechanical and electrochemical properties of the silicon dioxide layers formed by the deposition of nano physical vapor deposition on the surface of titanium and titanium 13‐niobium 13‐zirconium alloy samples were investigated. To evaluate the mechanical properties of the layers produced by this method, hardness tests were carried out, as well as tests on the adhesion of these layers to the metal substrate. On the other hand, electrochemical properties were studied using potentiodynamic measurements to assess the resistance to pitting corrosion, followed by impedance measurements to interpret the processes and phenomena occurring at the silicon dioxide layer/electrolyte interface. The data obtained showed different mechanical and electrochemical properties of the silicon dioxide layers generated with varying process parameters.

Structure and properties of samples made from XH50BMTJuB-VI (EP648-VI) alloy produced by using selective laser melting process

The paper presented examines the composition, the structure and properties of samples made from the XH50VMTJuB-VI (hereinafter EP648-VI) alloy obtained by using the selective laser melting process (the SLM-process) in relation to manufacturing parts for aviation purposes. The authors carried out a comparative study of the samples’ structure and properties upon conducting such operations as depositing in two directions (horizontal and vertical), separate heat treatment and after hot isostatic pressing (HIP) followed by a standard heat treatment process applied for deformable semi-finished products made from the XH50VMTJuB-VI(EP648-VI) alloy. The authors inform that the manufacturing of samples by means of the SLM-process involved powders obtained through the technology of the vacuum-induction spraying of the molten metal jet with an inert gas (argon). The paper has established that samples obtained by using the HIP process with the application of the heat treatment (a vacuum high-temperature homogenization followed by a long-term aging) demonstrated the best set of mechanical properties, since the implemented complex process ensured the “healing” of pores and discontinuities in the structure, and strengthening by means of the intermetallic g¢-phase, while separations of the excess, needle-shaped a -Cr phase are fine and evenly distributed in the material structure. The authors noted that mechanical properties of samples under analysis were generally in compliance with the requirements set forth in the regulatory documentation for deformable semi-finished products made from the XH50VMTJuB-VI (EP648-VI) alloy, while underlining the increase in the level of impact strength of samples that underwent the HIP process, and the long-term strength of samples manufactured in the vertical direction compared to other options studied. Following the results of the analysis, the authors established that the SLM-process made it possible to manufacture products whose level of mechanical properties was close to the level of the deformable material, and even exceeded it in some cases.

Analysis of the Uniformity of Mechanical Properties along the Length of Wire Rod Designed for Further Cold Plastic Working Processes for Selected Parameters of Thermoplastic Processing.

This study presents the results of research, the aim of which was to analyze the uniformity of the distribution of selected mechanical properties along the length of a 5.5 mm diameter wire rod of 20MnB4 steel for specific thermoplastic processing parameters. The scope of the study included, inter alia, metallographic analyses, microhardness tests, thermovision investigations, and tests of the wire rod mechanical properties (yield strength, ultimate tensile strength, elongation, relative reduction in area at fracture), along with their statistical analysis, for three technological variants of the rolling process differing by rolling temperature in the final stage of the rolling process (Reducing Sizing Mill rolling block [RSM]) and by cooling rate using STELMOR® cooling process. The obtained results led to the conclusion that the analyzed rolling process is characterized by a certain disparity of the analyzed mechanical properties along the length of the wire rod, which, however, retains a certain stability. This disparateness is caused by a number of factors. One of them, which ultimately determines the properties of the finished wire rod, is the process of controlled cooling in the STELMOR® line. Despite technological advances concerning technical solutions (among them, increasing the roller track speed in particular sections), it is currently not possible to completely eliminate the temperature difference along the length of the wire rod caused by the contact of individual coils with each other. From this point of view, for the analyzed thermoplastic processing parameters, there is no significant impact by the production process parameters on the quality of the finished steel product. Whereas, while comparing the mechanical properties and microstructure of the wire rod produced in the different technological combinations, it was found that the wire rod rolled in an RSM block at 850 °C and cooled after the rolling process on a roller conveyor at 10 °C/s had the best set of mechanical properties and the smallest microstructure variations. The wire rod produced in this way had the required level of plasticity reserve, which enables further deformation of the given type of steel in compression tests with a relative plastic strain of 75%. The uniformity of mechanical properties along the length of wire rods designed for further cold plastic working processes is an important problem. This is an important issue, given that wire rods made from 20MnB4 steel are an input material for further cold plastic working processes, e.g., for the drawing processes or the production of nails.

On the role of strain hardening and mechanical properties in water droplet erosion of metals

The role of strain hardening on the resistance of metals to water droplet erosion is investigated for the first time. A stainless steel (17–4PH) was heat treated to various conditions to achieve different sets of mechanical properties. Erosion tests were then performed at 250 and 300 m/s impact speeds and incubation time and erosion rate were measured. It was found that higher strain hardening is conducive to higher erosion resistance as demonstrated by longer incubation time. Strain hardening was also found to dictate the influence of other mechanical properties, such as yield strength and resilience, on the initial stages of erosion. It is concluded that erosion resistance is a synergistic combination of mechanical properties that includes a stain hardening parameter.

Effects of aluminum and silicon carbide on morphological and mechanical properties of epoxy hybrid composites

The present research focuses on the effects of aluminum (Al) and silicon carbide (SiC) hybridization on mechanical and morphological properties of Al and SiC particles reinforced hybrid epoxy composites. Composites were prepared by hand lay-up technique at five levels of reinforcement loading (10, 20, 30, 40, and 50 wt%). Aluminum powder and silicon carbide particles were utilized as reinforcement at a ratio of (1:1) during composite preparation. Microstructural analysis using a scanning electronic microscope and optical microscope was performed to observe the adhesiveness between the matrix and reinforcement. For mechanical characterization, tensile, flexural, impact, and hardness tests were performed. Tensile and flexural strength decreased, while Young’s modulus, flexural modulus, impact strength, and hardness increased with increase in aluminum and silicon carbide particle loading. Based on the particle loading, 50 wt% of particle-reinforced composite had the best set of mechanical properties among all prepared composites.

Multi-Criteria Selection of Quantitative Composition of Alloying Elements of Maraging Steels of the Fe–Cr–Ni–Mo System with an Improved Set of Mechanical Properties

Multi-Criteria Selection of Quantitative Composition of Alloying Elements of Maraging Steels of the Fe–Cr–Ni–Mo System with an Improved Set of Mechanical Properties

Mechanical Properties of Thermoplastic Polyurethane-Based Three-Dimensional-Printed Lattice Structures: Role of Build Orientation, Loading Direction, and Filler.

This study addresses the influence of build orientation and loading direction on the static and dynamic mechanical properties of three-dimensional-printed thermoplastic polyurethane-based lattice structures (with different cell shape). Specimens were printed in horizontal, 45° angle, and vertical orientations. Three-point bending tests showed that the investigated specimens are characterized by a strong anisotropy of the mechanical properties, which depends on the loading direction. In this regard, the influence of the loading direction is much stronger for the specimens printed vertically or at an angle of 45°, whereas the properties of the lattice structures printed horizontally are almost isotropic. The best set of mechanical properties (regardless of the loading direction) is shown by the samples of lattice materials, with square cells obtained by horizontal orientation of the polymer layers. The possibility of significant (one order of magnitude) increase in strength properties with satisfactory ductility is shown by using an epoxy polymer as a filler. A mathematical model of the bending of a mesostructured beam was established, which made it possible to describe qualitatively the various mechanisms of its destruction, such as: the breaking of the bonds between the polymer layers due to their mutual sliding and flaking, and the rapture of the layers themselves. The findings presented here provide new insights into the development of lattice structures with unique mechanical properties for a wide range of applications.

Thermomechanical Study and Thermal Behavior of Plasticized Poly(Lactic Acid) Nanocomposites

Poly (lactic acid) (PLA) is a useful alternative to petrochemical commodity material used in such as in food packaging industries. Due to its inherent brittleness, low thermal stability, and poor crystallization, it needs to improve its properties, namely in terms of thermal and mechanical performance. The plasticized PLA composites reinforced with nanofiller were prepared by solvent casting and hot press methods. Thermal and mechanical properties, as well as the crystallinity study of these nanocomposites, were investigated to study the effect of tributyl citrate (TBC) and TiO2 on the PLA composites. The addition of TBC improved the flexibility and crystallinity of the composites. Reinforcement of TiO2 was found as a practical approach to improve the mechanical properties, thermal stability, and enhanced crystalline ability for plasticized PLA nanocomposites. Based on the results achieved in this study, the composite with 3.5% nanofiller (pPLATi3.5) presented the optimum set of mechanical properties and improved thermal stability.

Study of the insulation and mechanical properties of hair-reinforced epoxy

This research reports the study of epoxy reinforced with human hair as a potential building material for the purpose of acoustic and thermal insulation for building industry. The sound insulation and thermal conductivity were studied for an epoxy composite reinforced with 15% human hair, together with a set of mechanical properties (tensile strength and flexural strength). The sound insulation results proved that the addition of hair led to about 75% loss of the sound intensity compared to the sound intensity noticed for the unreinforced specimen. Thermal conductivity decreased by about 20% with reinforcement. Mechanical properties show a significant improvement, such that flexural strength increased by 25%. The tensile test results showed a higher Young’s modulus and tensile strength for the reinforced specimen by about 50% and 27% respectively. Finally, flexural strength also showed an increase by about 20% after reinforcement.

SIMULATION OF SURFACE DEFORMATION USING INCONEL 718 DIC-ANALYSIS OF HEATING ALLOY

. Fracture is the final stage of metal behavior under load, and the resistance that themetal gives to the development of this process, largely determines its structural strength. Inconel718 is gaining strength mainly due to the dispersion hardening in the allocation of secondaryphases. Purpose: to establish a set of mechanical properties and microstructure of heatstrengthened Inconel 718 and to investigate changes in the degree of deformation of the surfacemetal by the method of registration of macroloca l fields. Mechanical properties were determinedby standard methods on three samples. Registration of macrolocal displacement fields wasrecorded by DIC (digital image correlation) method simultaneously with stretching. The dataobtained from the DIC analy sis showed that at the time of rupture the local deformation of thesample increased to 36% sample 1, up to 50% sample 2, up to 25% sample 3. It is shown thatthe microstructure of the studied samples is homogeneous, the detected grain γ structure with theformation of duplicates, the density of the experimental samples was 98.3%.

Development of recommendations on cooling rates of railway wheels with the use of modeling in the software package qform vx 8.2 for the formation of a homogeneous ferritic-perlite structure

The tests were performed on ER7 steel according to EN 13262. Based on the hardenability test (GOST 5657) by the method of end hardening (Jomen) the distance from the surface from which unilateral cooling was performed, where the hardness met the requirements of regulatory documentation for wheels of test steel, and the distance where the formation of needle structures, including bainite and otmanshtette, no longer took place. Simulation was applied in the software package QForm VX 8.2, as a result, a model was developed, for the adaptation of which the results of the experiment were used. Confirmed the high convergence of the results of the calculation and the experiment. At the same time, the model allowed to obtain an instantaneous cooling rate in a form that is more in line with the physical meaning of the process and to avoid the scatter of actual values associated with the discreteness of data capture. It is established that the instantaneous cooling rate changes in the process of continuous uniform supply of the cooler. The permissible range of cooling rates of the surface and central sections of the wheel rim during accelerated cooling of ER7 steel is determined. The data can be used to improve the heat treatment modes of railway wheels of current production in order to achieve a high set of mechanical properties both with the existing cooling technology and with differentiated cooling on the modernized equipment of the thermal section of the wheel shop. The developed model can be used to build thermokinetic diagrams under continuous cooling and to develop recommendations for heat treatment modes to achieve the specified mechanical properties under a certain structural state.

Quality index improving of the electric-welded K55 pipes

The pipes manufacturing process with using the high frequency welding process (HFW) is widely applied for the producing of casing pipes, pipes for infield, supply and main pipelines. One of the criteria for meeting pipes to customer requirements is to provide the necessary mechanical properties of the pipe body and the welded joint. The analysis of forming, welding and local heat treatment of the welded joint was carried out during mastering of K55 pipe production. Metallographic researches of the base metal and welded joint were carried out. Pipes acceptance tests have been performed in accordance with API 5CT requirements. Based on the results of the researches and tests, the key factors influencing on the microstructure of the welded joint were identified. The technology of thermomechanical treatment of the welded joint has been developed. New modes of forming and welding have been applied, which make it possible to reduce the effect of the actual anisotropy of metal in terms of the yield strength and ultimate strength on the quality of the finished product. This article describes one of the possible options for obtaining a set of mechanical properties in accordance with the requirements of the API 5CT for HWF pipes.

Influence of Heat Treatment on Residual Stress Formation in the Wear-Resistant Steel 60–Steel 15–Steel 60 Bimetal Material

We investigate the influence of heat treatment on the residual stress formation in the 7-mm-thick three-layer wear-resistant bimetal steel 60–steel 15–steel 60 sheet produced by hot rolling. We determine that the thickness of the cladding layers is ≈2–2.1 mm, the thickness of the main layer is ≈2.8–3 mm, and the transition zone width is ≈0.5–0.8 mm. We show that the most favorable distribution of the residual stresses and the set of mechanical properties will achieved after quenching and tempering at 300°C.

Mechanical and morphological properties of high density polyethylene-Al-SiC hybrid composites

ABSTRACT Hybrid composite refers to as an attractive structural material due to its ability to provide a better combination of properties with respect to single-particle-containing composite. Composites were prepared by using customised extruder machine at five levels (10, 20, 30, 40 and 50 wt%) of aluminium powder and silicon carbide loading. Microstructural analysis utilising scanning electron microscope and optical microscope was performed to observe the cohesiveness and distributions of matrix and reinforcement in the composites. Tensile, flexural, impact and hardness tests were conducted for the purpose of mechanical characterisation. Tensile strength increased up to 40 wt% particles loading and then decreased in 50 wt% particles loaded composite. Young’s modulus, flexural strength, flexural modulus, and hardness increased with the increase of aluminium powder and silicon carbide reinforcement loading. On the other hand, impact strength showed an opposite trend. Based on the particle loading and uniformity, 40 wt% aluminium powder and silicon carbide reinforced composite revealed the best set of mechanical properties.

An experimental study on carbon fiber thickness and layer thickness of depositing material in fused deposition modeling

Abstract The paper deals with analyses of results of a study on the effect of process parameters in fusion deposition modeling (FDM) 3D printing of a selected composite. Physical models of polylactic acid (PLA) and polylactic acid- carbon fiber (PLA-CF) composites are rapid prototyped through layer by layer deposition (Fusion deposition modeling) technique. Two important process parameters viz. layer thickness of depositing material and thickness of carbon fiber (CF) were optimized to achieve the best set of mechanical properties. Further, tensile strength and flexural strength of the products so fabricated are chosen as response variables so as to study the effects of process parameters on mechanical properties by the use of analysis of variance (ANOVA) technique. The experimental results revealed that the addition of increasing thickness of carbon fiber (CF) in polylactic acid (PLA) based composite raises the tensile strength over that of the pure PLA specimen. Moreover, the tensile strength was found to decrease with an increase in layer thickness of depositing material in CF-PLA composite. The study further revealed that mean flexural strength increases with increasing layer thickness, but, its dependence on CF thickness does not show any specific trend.

Mechanical Properties of Chemically Treated Banana and Ramie Fibre Reinforced Polypropylene Composites

Present research focuses on finding better fibre reinforcement cheap and eco-friendly polypropylene composite Mechanical Properties increased with increase in fibre loading and sodium carbonate Treatment. Banana and Ramie Fibres were chosen as reinforcement. The compression moulding technique was used to prepare the composite material. Fibre loading was varied at 0, 5 and 10% volume. Both raw Banana and Ramie Fibre was chemically treated with 5 wt% sodium carbonate and composites were also prepared with 0, 5 and 10% volume treated ramie and banana fibre. Analysis of prepared composites was subsequently conducted using Mechanical Tensile, flexural, hardness tests and. 10% fibre reinforced composite provided the best set of mechanical properties. It can be concluded after chemical treatment the mechanical treatment got enhanced.

Study of the Effect of Alloying and Hot Deformation on Properties of Small Stampings of Alloys Based on TiAl Intermetallic

Intermetallic alloys based on TiAl compound are most promising high-temperature materials for gas turbine engines. The effect of alloying TiAl with active elements together with hot deformation and heat treatment on the structure of stamped components is studied. Alloy composition is selected and hot pressure treatment and heat treatment parameters are selected providing an improved set of mechanical properties in stamped components.

Effect of peacock feather and rose stem fibre hybridisation on mechanical properties of polystyrene composites

ABSTRACT Natural fibre composites are developed to combat environmental challenges posed by non-biodegradable polymers such as littering in landfills. Other advantages of such composites include low cost, renewability and low density. In present research, polystyrene matrix composites were prepared with varying compositions of peacock feather barbs and retted rose stem fibre. The percentage of fibre used was 0, 5, 10 and 15%, while keeping feather to stem ratio at 1:1. The composites were compression moulded in a hot press machine. Later two more composites were prepared using 15% fibre loading and feather to stem ratio of 3:1 and 1:3. Tensile, flexural, impact and hardness tests of prepared composites were subsequently conducted. Tensile and impact strength decreased, while other mechanical properties increased generally with peacock feather and rose stem hybrid fibre loading. Composite containing feather and stem fibre at 3:1 ratio had highest tensile strength, flexural strength and impact strength, while composite containing feather and stem fibre at 1:1 ratio had highest Young’s modulus and hardness. Thus, composite containing 15 wt% peacock feather and rose stem fibre at 3:1 ratio had the best set of mechanical properties among all prepared composites.

STRUCTURE AND PROPERTIES OF COATINGS BASED ON FeCrAl AND Cr18Ni10T

The process of vacuum-arc deposition of protective coatings from multicomponent FeCrAl cathodes and 18Cr10NiT stainless steel onto fragments of Zr1Nb alloy claddings has been developed. The influence of the reaction atmosphere (vacuum, nitrogen, oxygen) during the deposition of coatings on their structure, mechanical and corrosion properties is investigated. Coatings deposited in vacuum from the Cr18Ni10T cathode have the best set of mechanical properties and corrosion resistance; whereas coatings based on FeCrAl require composition optimization. It has been established that coatings deposited from FeCrAl and stainless steel cathodes with a thickness of 20 μm significantly increase oxidation resistance and prevent the destruction of fuel cladding under exposure to air at 1150 °C for 1 h.