scholarly journals Influence of Al and Ti Additions on Microstructure and Mechanical Properties of Leaded Brass Alloys

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rajab Mohammed Hussein ◽  
Osama Ibrahim Abd
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Testing Machine ◽  
Optical Emission ◽  
Optical Microscope ◽  
Mechanical Tests ◽  
Compression Tests ◽  
Wear Properties ◽  
Microstructure And Mechanical Properties ◽  
Brass Alloys

Brass has an attractive combination of properties, namely, good corrosion resistance, good wear properties, and high thermal and electrical conductivity. In this study, influence of selected alloy additions (Al and Ti) on performance of leaded brass alloys (CuZn39pb3) was investigated. The observation of microstructures, compression tests, and hardness tests were performed. The results of metallographic and mechanical tests indicate some influence of small amount additives of Al and Ti. Optical emission spectrometer (OES), light optical microscope (LOM), micro-Vickers hardness tester, and compression testing machine were used in this investigation. Consequently, Al had a significant effect on microstructure and mechanical properties of CuZn39Pb3 alloy. A larger compression strength at 0.31% wt of Al was obtained, as compared with the other alloys. Adding of Al and Ti led to the modification of the microstructure; thus, the compression strength was increased.

scholarly journals Microstructure and Mechanical Properties of Hypo- and Hypereutectic Cast Mg/Mg2Si Composites

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3591
Author(s):  
Katarzyna N. Braszczyńska-Malik ◽  
Marcin A. Malik
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Eutectic Mixture ◽  
Weight Fraction ◽  
Uniaxial Tensile ◽  
Compression Tests ◽  
Magnesium Matrix ◽  
Magnesium Matrix Composites ◽  
Mg2si Phase ◽  
Microstructure And Mechanical Properties

In this paper, the microstructure and mechanical properties of two magnesium matrix composites—a hypoeutectic with 1.9 wt% Mg2Si phase and a hypereutectic with 19 wt% Mg2Si compound—were analyzed. The investigated materials were prepared using the gravity casting method. Microstructure analyses of the fabricated composites were carried out by XRD and light microscopy. The tensile and compression strength as well as yield strength of the composites were examined in both uniaxial tensile and compression tests. The microstructure of the hypoeutectic composite was in agreement with the phase diagram and composed of primary Mg dendrites and an Mg–Mg2Si eutectic mixture. For the hypereutectic composite, besides the primary Mg2Si phase and eutectic mixture, additional magnesium dendrites surrounding the Mg2Si compound were observed due to nonequilibrium solidification conditions. The composites exhibited a rise in the examined mechanical properties with an increase in the Mg2Si weight fraction and also a higher tensile and compression strength in comparison to the pure magnesium matrix (cast in the same conditions). Additionally, analyses of fracture surfaces of the composites carried out using scanning electron microscopy (SEM + EDX) are presented.

Effect of Original Microstructure on Microstructure and Mechanical Properties of High Strength Steel WHF1500H during Hot Forming

2018 ◽  
Vol 941 ◽  
pp. 206-211
Author(s):  
Wen Qiang Zhou ◽  
Li Bo Pan ◽  
Kuan Hui Hu ◽  
Wei Hua Sun ◽  
Rong Dong Han
Keyword(s):  
Mechanical Properties ◽  
Hot Stamping ◽  
Lath Martensite ◽  
Testing Machine ◽  
High Strength ◽  
Optical Microscope ◽  
Original Structure ◽  
Iron And Steel ◽  
Microstructure And Mechanical Properties ◽  
Austenite Grains

The press hardening steel sheets WHF1500H with different original structures produced by compact strip production (CSP) line in Wuhan Iron and Steel Ltd. were austenitized at 950 °C for 5 min, and then hot stamped and quenched by using the flat die. The microstructure and mechanical properties were investigated by optical microscope, transmission electron microscope and universal testing machine. The results show that the microstructure after stamping and quenching is fully composed of lath martensite. The mechanical properties of the steel samples with different original structures are different after hot stamping and quenching, and this difference is smaller than that before hot stamping and quenching. When the original structure consists of ferrite and pearlite, the austenite grains after austenitization are fine and uniform. In addition, the martensite structure obtained after hot stamping and quenching is also uniform and fine, leading to higher mechanical properties. With the increase of the strength of the original steel, when the original structure is martensite, the austenite grains after austenitization are coarse, and the martensite structures obtained after quenching is also coarse, and thereby decreasing the strength.

Effect of Ti Additions on Microstructure and Mechanical Properties of Centrifugally Cast 25Cr-35Ni-Nb Alloy

2016 ◽  
Author(s):  
Tao Chen ◽  
Chen Xue-dong ◽  
Xiao-ming Lian ◽  
Zhi-chao Fan
Keyword(s):  
Mechanical Properties ◽  
Testing Machine ◽  
Optical Emission ◽  
Creep Rupture ◽  
Image Analyzer ◽  
Tensile Testing Machine ◽  
Centrifugally Cast ◽  
Microstructure And Mechanical Properties ◽  
Furnace Tube ◽  
Ti Content

The influence of Ti element with the content from 0.018 wt.% to 0.112 wt.% on microstructure and mechanical properties of centrifugally cast 25Cr-35Ni-Nb alloy was investigated in this paper. The experiments were carried out by optical emission spectrometer, metallographic image analyzer, field emission gun scanning electron microscopy (FEG-SEM) equipped with an Oxford INCA energy dispersive X-ray spectrometer (EDS), tensile testing machine and creep testing machine. The results show that the microstructure and high temperature creep rupture properties of as-cast 25Cr-35Ni-Nb alloy are significantly affected by the addition of Ti. No precipitation of Ti carbides was observed in the alloy with the Ti content of 0.018 wt.%, whereas the skeleton (Nb, Ti) C were precipitated at grain boundaries when increasing the Ti content. Under the creep rupture condition of 1100 °C and 17 MPa, the rupture lives of 25Cr-35Ni-Nb alloy with Ti contents ranging from 0.04 wt.% to 0.112 wt.% were relatively higher. In addition, the role of Ti in ethylene pyrolysis furnace tube was also discussed in this paper.

scholarly journals Study of Mechanical Properties of Heat treated AL 7075/Graphite Powder/Baggasse Ash hybrid MMCs

2020 ◽  
pp. 203-211
Author(s):  
Meghashree K A ◽  
Puneeth P ◽  
Madhu M G ◽  
H K Shivananda
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Research Work ◽  
Testing Machine ◽  
Graphite Powder ◽  
Compression Tests ◽  
Standard Size ◽  
Casting Technique ◽  
Heat Treated ◽  
Al 7075

This research work investigated the influence of the graphite powder on the Mechanical behaviour of Aluminium 7075/Graphite Powder(Gr)/Bagasse Ash(BA) hybrid composite. This investigation reveals the effectiveness of incorporation of graphite powder in the composite for gaining enhancing mechanical properties. The Al7075 (Aluminium alloy 7075) reinforced with bagasse ash and graphite powder to form MMCs were investigated. The conventional liquid casting technique was used for the fabrication of the composite material and subject to T6 heat treatment. The composite was produced for different percentages of graphite powder and bagasse ash. The specimens were prepared as per ASTM standard size by turning and facing operations to conduct tensile tests, compression tests and hardness tests. The specimens for tensile and compression strength are tested using universal testing machine and for hardness they are tested using Brinell hardness testing machine. The reinforcement content was chosen as 2,4, 6wt.% of Graphite powder to identify its potential for self lubricating property under dry sliding conditions. Through the results, it is concluded that the MMC obtained has got better tensile strength, compression strength, yield strength and hardness properties when compared to non-heat-treated Al 7075 alone.

scholarly journals The Influence of Casting Geometry on the Tensile Properties and Residual Stresses in Aluminium Castings

2010 ◽  
Vol 652 ◽  
pp. 174-179
Author(s):  
Mohsen Sadrossadat ◽  
Sten Johansson
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Residual Stresses ◽  
Testing Machine ◽  
Optical Microscope ◽  
Microstructural Development ◽  
Stress Evolution ◽  
Rectangular Grid ◽  
Tensile Testing Machine ◽  
Microstructure And Mechanical Properties

The soundness and the performance of castings are significantly affected by generation and accumulation of residual stresses. This has been proven that mechanical properties and residual stresses level of the casting components are affected by thermal gradient across the casting component during cooling and some intrinsic physical properties of the material. In the present work, microstructural development, mechanical properties, residual stress evolution and cooling curves associated with different legs of a mixed–section grid castings have been investigated employing scanning electron microscope, optical microscope, 3D measurement equipment, computerized thermal data acquisition instrument and tensile testing machine. Experimental results show that the accumulated residual stress in circular, triangular and rectangular grid shapes is increasing respectively. From the results it can be seen that there are clear influences of grid’s geometry on the microstructure and mechanical properties. The geometrical stiffness can affect a lot the residual stress level and the casting modulus has a big influence on the microstructure and mechanical properties.

Mechanical Properties of Multi Axially Forged Hybrid Composite

2015 ◽  
Vol 813-814 ◽  
pp. 90-94
Author(s):  
A. Saravana Kumar ◽  
P. Sasikumar
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Compression Strength ◽  
Hybrid Composite ◽  
High Strength ◽  
Stir Casting ◽  
Optical Microscope ◽  
Unreinforced Alloy ◽  
Casting Technique ◽  
Microstructure And Mechanical Properties

This work investigated the influence of multi axial forging (MAF) on the microstructure and mechanical properties of AA6063/Al2O3/Gr hybrid composite. It reveals that the effectiveness of forged composite exhibited better mechanical properties. The AA6063 reinforced with Al2O3 and 1 wt. % graphite (Gr) hybrid composite were fabricated using stir casting technique. The microstructure of the hybrid composite was examined using optical microscope. The mechanical properties in terms of hardness, flexural strength and compression strength were investigated. It was observed that the mechanical properties of multi axially forged hybrid composite exhibited around 15, 7 and 5 times higher than unreinforced alloy, as-casted hybrid composite and as-hardened hybrid composite. These results revealed that the multi axially forged hybrid composite would be well suited for high strength applications.

scholarly journals Formation conditions and mechanical properties of aggregates produced in tephra–water–snow flows

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Hirofumi Niiya ◽  
Kenichi Oda ◽  
Daisuke Tsuji ◽  
Hiroaki Katsuragi
Keyword(s):  
Mechanical Properties ◽  
Mixing Time ◽  
Testing Machine ◽  
Small Scale ◽  
Scaling Analysis ◽  
Compression Tests ◽  
Ice Slurry ◽  
Experimental Conditions ◽  
Formation Conditions ◽  
Snow And Ice

Abstract The formation of aggregates consisting of snow, water, and tephra has been reported in small-scale experiments on three-phase flows containing tephra, water, and snow, representing lahars triggered by snowmelt. Such aggregates reduce the mobility of mud flow. However, the formation mechanism of such aggregates under various conditions has not been investigated. To elucidate the formation conditions and mechanical properties of the aggregates, we performed mixing experiments with materials on a rotating table and compression tests on the resulting aggregates with a universal testing machine in a low-temperature room at $$0\,^{\circ }\text {C}$$ 0 ∘ C . From experiments with varying component ratios of the mixture and tephra diameter, the following results were obtained: (i) the aggregate grew rapidly and reached maturity after a mixing time of 5 min; (ii) the mass of aggregates increased with snow concentration, exhibiting an approximately linear relationship; (iii) single aggregates with large mass formed at lower and higher tephra concentrations, whereas multiple aggregates with smaller mass were observed at intermediate concentrations; (iv) the shape of the aggregate satisfied the similarity law for an ellipsoid; (v) the compressive mechanical behavior could be modeled by an empirical nonlinear model. The obtained mechanical properties of the aggregates were independent of the experimental conditions; (vi) scaling analysis based on the Reynolds number and the strength of the aggregates showed that the aggregates cannot form in ice-slurry lahars. Our findings suggest that low-speed lahars containing snow and ice are likely to generate aggregates, but snow and ice in the ice-slurry lahars are dispersed without such aggregates.

Microstructure and mechanical properties of 15-5 PH stainless steel under different aging temperature

2021 ◽  
Vol 118 (6) ◽  
pp. 601
Author(s):  
Chunhui Jin ◽  
Honglin Zhou ◽  
Yuan Lai ◽  
Bei Li ◽  
Kewei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Aging Temperature ◽  
Electron Backscatter Diffraction ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Second Phase ◽  
Strengthening Mechanisms ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron

The influence of aging temperature on microstructure and mechanical properties of Cr15Ni5 precipitation hardening stainless steel (15-5 PH stainless steel) were investigated at aging temperature range of 440–610 °C. The tensile properties at ambient temperature of the 15-5 PH stainless steel processed by different aging temperatures were tested, and the microstructural features were further analyzed utilizing optical microscope (OM), transmission electron microscope (TEM), electron backscatter diffraction (EBSD) as well as X-ray diffraction (XRD), respectively. Results indicated the strength of the 15-5 PH stainless steel was firstly decreased with increment of aging temperature from 440 to 540 °C, and then increased with the increment of aging temperature from 540 to 610 °C. The strength and ductility were well matched at aging temperature 470 °C, and the yield strength, tensile strength as well as elongation were determined to be 1170 MPa, 1240 MPa and 24%, respectively. The microstructures concerning to different aging temperatures were overall confirmed to be lath martensite. The strengthening mechanisms induced by dislocation density and the second phase precipitation of Cu-enriched metallic compound under different aging temperatures were determined to be the predominant strengthening mechanisms controlling the variation trend of mechanical properties corresponding to different aging temperatures with respect to 15-5 PH stainless steel.

scholarly journals Microstructure and Mechanical Properties of 34CrNiMo6 Steel Repaired by Friction Stir Processing

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 279 ◽  
Author(s):  
Zhongwen Wu ◽  
Chunping Huang ◽  
Fencheng Liu ◽  
Chun Xia ◽  
Liming Ke
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Processing ◽  
Steel Structures ◽  
Optical Microscope ◽  
Filling Material ◽  
Welding Wire ◽  
Friction Stir ◽  
Filling Materials ◽  
Microstructure And Mechanical Properties ◽  
34Crnimo6 Steel

Repairing damaged parts using proper repairing methods has become an important means to reduce manufacturing and operational costs and prolong the service life of 34CrNiMo6 steel structures. In the conventional fusion repairing method, welding wire and powder are often used as filling materials. Filling materials are often expensive or difficult to find. Some metallurgical issues (such as solidification crack, higher distortion) were also found with these methods. At the same time, most of the equipment that requires welding wire and powder is expensive. In this study, a new method based on friction stir processing (FSP) was successfully employed to repair 34CrNiMo6 steel, using a block as filling material. Filling blocks are much cheaper than conventional fusion repair consumables. As a result of solid-state repair, this method can also avoid the metallurgical issues of fusion repair. The microstructure and mechanical properties of the repaired samples were investigated using OM (Optical Microscope), SEM, EDS (Energy Dispersive Spectroscopy), XRD, and a Vickers hardness electronic universal tensile tester. The results showed that 34CrNiMo6 steel was successfully repaired by this method, with no defect. Tensile tests showed that the maximum ultimate strength (UTS) was 900 MPa and could reach 91.8% of that of the substrate. The fracture mode of the tensile samples was ductile/brittle mixed fracture. Hence, the repairing method based on FSP appears to be a promising method for repairing castings.

scholarly journals Experimental Measurements of Mechanical Properties of PUR Foam Used for Testing Medical Devices and Instruments Depending on Temperature, Density and Strain Rate

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4560 ◽  
Author(s):  
Zdenek Horak ◽  
Karel Dvorak ◽  
Lucie Zarybnicka ◽  
Hana Vojackova ◽  
Jana Dvorakova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Mechanical Testing ◽  
Medical Devices ◽  
Optical Microscope ◽  
Surgical Instruments ◽  
Effect Of Temperature ◽  
Experimental Measurements ◽  
Compression Tests ◽  
Biomedical Material

Rigid polyurethane (PUR) foam is products used as a biomedical material for medical device testing. Thermal stability is a very important parameter for evaluating the feasibility of use for testing surgical instrument load during drilling. This work aimed to perform experimental measurements to determine the dependence of the mechanical properties of a certified PUR on temperature, strain rate and density. Experimental measurements were realised for three types of the PUR samples with different density 10, 25 and 40 pounds per cubic foot. The samples were characterised in terms of their mechanical properties evaluated from tensile and compression tests at temperatures of 25 °C, 90 °C and 155 °C. Furthermore, the structures of the samples were characterised using optical microscope, their thermal properties were characterised by thermogravimetric analysis, and their density and stiffness with the effect of temperature was monitored. The results show that it is optimal not only for mechanical testing but also for testing surgical instruments that generate heat during machining. On the basis of experimental measurements and evaluations of the obtained values, the tested materials are suitable for mechanical testing of medical devices. At the same time, this material is also suitable for testing surgical instruments that generate heat during machining.

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