Brinell Hardness Test Research Articles

Investigation of fatigue life of draw hook equipment used in freight wagon: Miscellaneous result

The coupling set, exposed to multi-directional severe dynamic loads, is a vital part that connects the wagons in rail system vehicles. These loads are usually transferred through the hook body in the draw hook coupler variant. Recently, some researchers have suggested that draw hook equipment suffers from fatigue damage if periodic maintenance is not performed correctly. For this reason, transportation safety is in danger. This study investigated fatigue occurring in the draw hook body and other metallurgical and mechanical properties affecting fatigue experimentally and numerically. The microstructure characterisation of the material was made using optic microscopy, electron spectrometry and scanning electron microscopes. The Brinell hardness and tensile test examined the material's mechanical properties. The fatigue behaviour rotating bending test and the complex S-N curves were obtained. For the computer validation of fatigue behaviour, stress life and strain life fatigue analyses were carried out using a commercial ANSYS program package. The high and low cycle fatigue regions are highlighted in the S-N curves. The endurance limit for the stress of 424.6 MPa was determined at 1.3 × 107 cycles.

UNDERSTANDING CONSTRUCTION ALLOYS: PROPERTIES UNVEILED

This article presents an experimental study on the characterization of carbon steels, alloy steels, aluminum alloys, brass, and cast iron commonly used in the construction industry. The focus is on evaluating the mechanical properties of these materials through optical microscopy and Brinell hardness testing. A series of samples representing each material type were prepared and subjected to optical microscopy analysis to examine their microstructural characteristics. The images obtained were further analyzed using ImageJ software to measure the size of various microstructural constituents. Additionally, the Brinell hardness test was conducted on each sample to quantify their mechanical strength and resistance to indentation. The experimental results provide valuable insights into the microstructural characteristics and mechanical properties of these construction materials, aiding in the selection and design of appropriate alloys for specific construction applications. The findings also contribute to the broader understanding of carbon steels, alloy steels, Si-Al, brass and cast iron, offering potential improvements in construction material selection and performance.

ANALYSIS OF RESIDUAL STRESS BY X-RAY DIFFRACTION AND STUDY OF MICROSTRUCTURE IN WELDED JOINT OF ASTM A-36 MARINE STEEL

ASTM A-36 marine steel is one of the most used and classified as a medium strength carbon steel. Its characteristics and purpose are in common applications and in metallic structures in general, sawmills, walkways, agricultural machinery and implements, road, rail and oil implements. It is used in angles, round, flat and square bars and I, U and T profiles. In this work, 10 mm sheets, with a V chamfer, were welded using the MIG/MAG process and X-Ray Diffraction measurements were carried out to study of residual stresses caused by the welding process. Then samples were taken for metallography and microscopy in the Scanning Electron Microscope (SEM). They were also performed in the three regions of the weld: base metal (MB); thermally affected zone (ZTA) and in the molten zone (ZF) Brinell hardness tests, to determine the energy stored in the regions of the weld bead. Vickers Microhardness measurements were also made at the ZTA, as it is a very narrow range, to give more precision to the hardness measurements. The X-Ray Diffraction test showed that the air-cooled samples are compressive and the water-cooled samples are tensile. The micrographs of the samples, in the region of the weld, showed that the ferritic phase prevailed in the molten zone. It was also observed the precipitation of carbides and alloying elements, in addition to the presence of martensite. It is concluded, therefore, that the results for the MIG/MAG welding were satisfactory and recommended for the welding of ASTM A-36 Steel.

Furnace Engine Modification to Lower Power

Furnace machine or heating furnace is a tool used for heat treatment processes or usually called heat treatment, furnace machines have several types from the beginning found furnace machines, namely induction furnaces/conventional furnaces and then transformed into electric furnaces, electric furnaces are more often used for processes heat treatment because it is cleaner compared to the convection furnace.The furnace machine requires 5000 watts of power, 13.1A. to reach the temperature of 8000 takes 7296 seconds. Furnace machine testing is by quenching using ST-42 steel which is held at 6000 and varying time, the first test material is not treated with heat traetment, for the second test material with a variation of 15 minutes, third 30, fourth 60, fifth 90, sixth 120 minute. the results of the quenching process were tested using the Brinell and Vickers hardness test methods.

Comparative Studies on Mechanical Properties and Corrosion Rate of Nickel Chromium Carbide (Cr3C2-NiCr) Coated on Inconel 600, 625, 718 Specimen

In this present work, Nickel Chromium Carbide (Cr3C2-NiCr) coated on three different Inconel 600, 625, 718 Specimen are used and the mechanical properties, corrosion resistance and morphological properties of the specimen were investigated by conducting Brinell hardness test, Vickers Hardness Test, Tensile test and electrochemical test experiments respectively and found that Inconel 625 has maximum hardness, maximum tensile strength and less corrosion resistance as compared to the remaining two coated Inconel specimen 600 & 718. And then coated surfaces of Inconel 600, 625 and 718 specimens were analyzed by using Scanning Electron Microscope (SEM), XRD, EDAX and optical microstructure techniques.

Effect of post-weld heat treatment on mechanical properties and microstructure in electric arc welded mild steel joints

Mechanical and microstructure properties of weld joint between mild steel plates before and after heat treatment process have been studied. In this study, electric arc welding was used as a welding method as it is the most common welding method. Then heat treatment of the samples were done in the furnace. Firstly, in the heat treatment process, stress annealing was done as stress generated at different places in the welding zone and after that full annealing was done using furnace cooling for cooling purpose. Tensile strength was measured using ASTM A370 standard specimen and Brinell hardness test was done at different surfaces of the welding zone. The microstructures were observed by cutting the specimen in a certain shape, and mirror surfaces were generated to observe in electron microscope. From the results, it was observed that PWHT causes a 4.1 % increase in tensile strength, a 13.84 % gain in yield strength, and a 4.96 % rise in percentage elongation. However, the value of hardness decreased 19.19 % after heat treatment as heat treatment increased the ductility of the specimen. At the place of the Electric Arc Welding joint, a smaller grain size, a lower gap between the grains, and comparatively few voids were identified.

Failure Analysis of Cracking on the Outer Pipe of 12Cr1MoV Water Wall in Thermal Power Plants

In order to identify the main causes of cracking and leakage of 12Cr1MoV water wall tubes outside the furnace in thermal power plants, this paper uses macroscopic morphology observation, stereomicroscope observation, alloy composition analysis, Brinell hardness test, metallographic structure inspection, and other means to detect and analyze the failed water wall tube. The alloy composition content of the water wall tubes submitted for inspection is within the standard requirements, and the Brinell hardness value of the water wall tubes also meets the requirements of relevant standards, The matrix metallographic structure of the water wall tube is normal. The initial leakage point is the cracking of the fillet weld at the end of the water wall tube fin, while other leakage points are caused by the blowing of the medium leaked from the initial leakage point. The initial leakage point is formed by the fatigue crack initiated at the fillet weld of the fin end and the corrosion crack on the inner wall extending towards each other. It is recommended to further inspect whether there is still cracking at the end of adjacent water wall tube fins to prevent similar cracking from happening again. Due to the frequent changes in the “peak shaving” period and amplitude in recent years, it is necessary to design the peak shaving period or amplitude reasonably to ensure the safe operation of the boiler.

Effect of Cu Addition on Properties of an Al-La Alloy

The effect of copper content on the microstructure and properties of an aluminum copper alloy containing lanthanum was studied by adding 0.5 wt% lanthanum and different contents of copper to the 2A12 alloy. We used a universal testing machine, Brinell hardness tester, and friction and wear testing machine to test the mechanical properties of the alloy. The microstructure and phase composition of the alloy were analyzed using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The results show that, after adding La and Cu, the alloy grain is refined, and the fracture mode changes from dissociation fracture to quasi dissociation fracture. A new phase containing La accumulates at the grain boundary. If the amount of Cu added is too large, the tendency for hot cracking increases, which can easily lead to the formation of voids or even cracks. The tensile strength and hardness of the cast alloy significantly increase with the increase in Cu addition. In the range of adding 2 wt% to 5 wt% Cu, the tensile strength and hardness of the cast alloy increases by approximately 12% and 17.84%, respectively, compared with the original alloy. With the increase in Cu addition, the elongation of the alloy first increases and then decreases, reaching its maximum value when Cu addition is 3 wt%. Adding Cu is beneficial for improving the wear resistance of the alloy. When the addition of Cu is 3 wt%, the alloy has the best wear resistance and minimum wear amount. This is due to the enrichment of La and Cu at the grain boundaries, forming new La phases or other phases with higher hardness, which changes the properties of the alloy. It shows that the content of Cu in the 2A12 alloy can be increased to 7-8% with the increasing of additional rare-earth elements, and a new Al-Cu (7 wt% to 8 wt%)-Mg (1.2 wt% to 1.8 wt%)-Mn (0.3 wt% to 0.9 wt%)-La (0.5 wt%) alloy, in which tensile strength, hardness, and elongation of the alloy are increased by 8.1%, 16%, and 79.1%, respectively, can be formed. In addition, the wear resistance of Al-La alloys also improves significantly with the addition of copper content. The coefficient of friction is reduced by 68% compared with no copper addition.

Effect of Ultrasonic Treatment on Microstructure and Properties of Gray Cast Iron

The effect of ultrasonic treatment on the microstructure and properties of gray cast iron was studied. The samples were analyzed by metallographic microscope, scanning electron microscope, Brinell hardness tester, electronic universal testing machine, etc. The results showed that ultrasonic treatment could improve the pearlite content in the microstructure. After ultrasonic treatment, the tensile strength of gray cast iron can be improved to 266 MPa, which is 11.60% higher than that of the samples without ultrasonic treatment. Ultrasonic treatment can refine the size of graphite, which can reduce the stress concentration. In addition, the pearlite lamellar spacing can also be reduced, which is the main reason for improving the mechanical properties of gray iron.

Bonding strength and microstructural features of Al5083-AZ31B alloys laminated sheet through friction stir additive manufacturing

Industries such as aerospace, robotics, defence, light aircraft, and transportation are increasingly in need of lightweight and strong materials. Aluminium-magnesium alloys are the preferred choice due to their high strength and stiffness-to-weight ratios compared to traditional materials. This study utilized an innovative technique called friction stir additive manufacturing (FSAM) to develop a laminated sheet of Al5083-AZ31B alloys for multipurpose applications. The effect of the rotational speed of the tool is examined over the microstructural features and bonding strength of the lamination. The study examined the macrostructural and grain refinement results at the interfacial layer through light microscopy, FESEM and EBSD analysis. XRD test has been conducted and discussed in terms of crystallographic planes and chemical compounds at the interfacial layer. To validate the specimen’s bonding strength, tensile tests and Brinell hardness tests are conducted. The result reveals a higher ultimate strength of 297.25 MPa at 2000 rpm while lower strength is observed at 234.47 MPa for rotational speed at 1000 rpm. The maximum BHN of 71.1 is recorded at a rotational speed of 2000 rpm The strong interfacial compounds such as Al4Fe, and Mg2Al3 are supports the bonding strength and increase hardness.

XRD Observation on the Weld Metal of Resurfaced Rail Steel

The current research studied two samples of rail steel grade 900A deposited with different electrodes, namely, electrodes A and B, using the Shielded Metal Arc Welding (SMAW) process. This research fi nds out the suitable hardness values of the various electrodes. The phase identifi cation and microstructural analysis of weld metal were conducted using X-ray diffraction (XRD) and an optical microscope, respectively. The micro-hardness profi les along the cross-section of the weldment were acquired using a micro-Vickers hardness tester, and a Brinell hardness tester measured the hardness values on the top surface of the weld metal. According to the results, the diffraction angles of the XRD patterns for all weld metal samples differed due to their distinct microstructures. The microstructure of the weld metal, in particular, produced the primary infl uence on the hardness

Mechanical properties of Norway spruce (Picea abies) infested by the bark beetle (Ips typographus)

ABSTRACT This study considered the mechanical properties of primary blue-stained sapwood of Norway spruce infested by the bark beetle Ips typographus. Nineteen stems from Stammerberg (ZH, Switzerland) were harvested in three different seasons and after different periods of bark beetle outbreaks. Density, Brinell hardness including elastic recovery after load, and key strength properties were tested on blue-stained wood and non-infected controls. Differences in mechanical properties were analysed according to the stand and storage time of the stems after the bark beetle attack. Spruce harvested at a late stage after the bark beetle attack (2–3 months) showed a clear reduction in impact bending strength, a significant loss in surface elastic recovery after indentation during Brinell hardness test, and a striking number of specimens with brittle fracture behaviour during Three-Point-Bending. Light microscopy and the results of the mechanical tests give clear evidence to suggest that wood-degrading fungi are already active in addition to the sap-staining fungi. Especially after larger outbreaks of bark beetles, it must be assumed that sapwood of Norway spruce does not only show the typical blue stain, but also incipient stages of wood degradation by wood-degrading fungi.

Development of aluminium-tin alloy for high strength application

This study looks into the preparation of an aluminium-tin alloy for high strength applications. The aluminium base metal was melted using a gas-fired lift-out crucible furnace. The basic aluminium (>99% Al) was melted first, and the control sample was cast into one of the prepared moulds at 710 °C. This inquiry was divided into two stages, the first being casting manufacture and the second being experimental testing. In the first stage, a set amount of aluminium and tin ingots were placed within a massive crucible and melted at temperatures of 710 °C, which is somewhat higher than the melting temperature of aluminium (680 °C). The investigation's second phase entails analyzing the microstructure and properties of the product. The investigation's main focus was on the tensile strength, metal composition, and mechanical characteristics of the aluminium-tin alloy. Tensile specimens of ASTM standards were prepared in the longitudinal direction and tested using a Universal Testing Machine to ascertain the tensile strength (UTM). Micro hardness was assessed using a Brinell Hardness Tester. In order to determine how the alloys' metal composition manifested itself in their microstructure, the optical microscope and scanning electron microscope (SEM) observations of the alloys were mostly used.

Surface and corrosion properties of corn cob and egg shell particles reinforced AA3104-H19 composite via stir casting process

Aluminium alloys have been the most commonly used materials in the automotive and marine industries. However, depreciation in strength due to contact with environmental contaminants occurs over time. Hence, this study examined the effect of corn cob (CC) and egg shell (ES) particles on the corrosion, hardness and microstructure properties of AA3104-H19 composite. The corrosion experiment was conducted in 3.65 wt% NaCl solution. The microstructure of the material was examined with a scanning electron microscope (SEM) and X-ray diffractometer (XRD). The hardness was measured using a simple Brinell hardness tester loading. The control sample (AA3104-H19 alloy) exhibited the highest corrosion rate (CR) and corrosion current density (jcorr) of 0.0914 mm/year and 7.867 μA/cm2, respectively, Al90%-CC10%-ES0% sample exhibited the lowest CR and jcorr of 0.0135 mm/year and 1.16 μA/cm2, respectively. More so, the control sample exhibited a Brinell hardness of 96.3 kgf/mm2, while the Al90%-CC0%-ES10% sample exhibited an improved Brinell hardness of 99.6 kgf/mm2. The low corrosion rate of Al90%-CC10%-ES0% and high Brinell hardness Al90%-CC0%-ES10% of samples indicated that the samples exhibited superior corrosion resistance and enhanced resistance to indentation, respectively, relative to the other test samples. The SEM images revealed that the reinforced samples exhibited more uniform morphology than the control sample. The presence of AlSiO2 as indicated by the XRD results could have enhanced the corrosion rate of the material. The ESD revealed elements such as Ca, Mg, Si, Al and C, which are beneficial to the surface and corrosion properties of the material.

Environmentally friendly protection of European beech against fire and fungal decay using a combination of thermal modification and mineralisation

ABSTRACT The demand for construction timber is continuously increasing, due to its favourable characteristics. However, the adequate protection of wood is key to its successful use, as it is flammable and susceptible to biodegradation. Given that thermal modification enhances the durability of wood, and mineralisation with CaCO3 considerably improves its fire properties, it is worth considering the combined effects of the two methods. European beech (Fagus sylvatica) was selected to determine the effects of a) thermal modification, b) mineralisation through the in-situ formation of CaCO3, and c) a combination of the two procedures, on resistance to decay fungi, reaction to fire and the mechanical properties of the wood. Microscopic analysis and comparisons of the samples before and after exposure to fungi were also conducted. Mineralised wood generally had a slightly alkaline pH value and higher equilibrium moisture content, while thermal modification lowered the equilibrium moisture content. The present study demonstrated the combined effect of thermal modification and mineralisation: the best response to fire as well as resistance to fungi was achieved when the two treatments were combined. Results from the Brinell hardness and three-point bending tests indicate that both modification procedures can slightly impair the mechanical properties of the wood.

Investigation of the microstructure, hardness, and compressive properties of TaC-reinforced lamellar graphite cast irons

Tantalum Carbide (TaC) reinforcement was made to lamellar graphite (gray) cast irons that were produced in the physical conditions of a foundry at reinforcement ratios of 0%, 0.025%, 0.155%, and 0.285%. Samples complying with standards were prepared using the TaC-reinforced lamellar graphite (gray) cast iron alloys that were produced, and Brinell hardness tests, compressive strength tests, and microstructural analyses were conducted. According to the test results, the highest average Brinell hardness value was found as 231 HB in sample A which was reinforced at a ratio of 0.025%. In general, as the reinforcement ratio increased, there was an increase in the hardness test measurement results. The highest average compressive strength value was found as 949 MPa in sample C which was reinforced at a ratio of 0.285%. In general, as the reinforcement ratio increased, there was an increase in the compressive strength values. The results of the microstructural analyses showed that the reinforcement material was dispersed into the matrix.

Analysis of mechanical properties of 3D printed metallic specimens of aluminum (CL31) bronze (CL80) material manufactured at varying laser scanning speed

In our research work, we analyzed the mechanical properties of 3D-printed metallic specimens of aluminium bronze material. In our evaluation, we had five groups of specimens, manufactured at different laser scanning speeds. In total, we had 25 specimens for which we examined various parameters like ultimate tensile strength, engineering yield point, relative strain, and hardness. Results showed that specimens prepared with a lower laser scanning speed of 300mm/s showed the lowest tensile strength. The tensile strength increased with increasing laser scan speed and the highest tensile strength was attained by specimens of the fourth group that were produced at a laser scanning speed of 500mm/s. The relative strain of specimens also increased with the increasing scan speed of the laser. The Brinell hardness test also showed an elevation in hardness values with increasing laser scan speeds.

Effect of tempering temperature and subzero treatment on microstructures, retained austenite, and hardness of AISI D2 tool steel

The presence of retained austenite in the hardening process of tool steel often causes the lower hardness compared to the hardness requirements and poor dimensional stability in the tool steel. The purpose of the present research is to determine the relationships between the tempering process with and without cryogenic treatment to the hardness and retained austenite amount of as-hardened D2 tool steel. The austenitizing temperature was 1020 °C, the tempering temperatures have variations of 180 °C, 280 °C, 380 °C, 480 °C, and 580 °C, and the subzero treatment has a temperature of −172 °C, followed by tempering at 180 °C, 380 °C, and 580 °C. This study aims to determine the appropriate treatment to obtain a minimum retained austenite percentage to prevent and mitigate the failure of AISI D2 tool steel in the industrial application process. An optical microscope with image processing software (Image-J analysis), as well as Brinell and Vickers hardness testing, is the characterization method used in this work. In general, plate martensite, bainite, retained austenite, and primary and secondary carbides are the phases contained in the microstructure. Tempering temperatures have the effect of increasing the secondary carbide precipitation and decreasing the retained austenite content (γr 3,671%–2,769%). However, the cryogenic treatment can provide a more efficient martensitic phase transformation process and minimal retained austenite content (γr 2,257%–1,199%). The increase in tempering temperature causes a decrease in hardness at a temperature of 180 °C–380 °C. On the other hand, the secondary hardening and phase transformation phenomena cause an increase in the hardness of the as-tempered sample at a temperature of 480 °C, before the sample reexperiences a significant decrease in hardness at a temperature of 580 °C due to diffusion that decreases the carbon content.

Mechanical and tribological characterization of Al1070 alloy based self- lubricating metal matrix composites

Lubrication is provided to decrease the friction and wear among the mating parts of machines used in various industrial applications. Lubrications are of different types like solid lubricant, semi-solid lubricant and liquid lubricant etc. Solid lubricants are basically used a places where material which provide lubrication under dry conditions. But the most use lubricants are liquid lubricant that we use in today’s life like organic mineral oils. But, these liquid lubricants can’t survive under extreme loading, temperature and under the places where vacuum is required. Self-lubricating metal matrix composites (SLMMC) have excellent tribomechanical properties and are used in different critical applications such as in aerospace, Engine piston, Engine cylinder, propeller shafts and as bearings materials etc. SLMMC doesn’t have any such requirement and they are normally reinforced with different weight proportions of graphite, silicon carbide and MoS2 etc. In this paper, MoS2 is reinforced in 7.5 % wt with Al1070 base alloy for fabrication of SLMMC using stir casting technique. A Pin on disc machine is used to study the friction, wear and Brinell hardness tester for measurement of hardness, respectively. 25–33 % increase in coefficient of friction (COF) and 37–58 % increase in wear rate (WR) were obtained at higher loading and rotational speed, respectively. 15.38 % improvement in hardness is achieved after reinforcement with 7.5 % MoS2 solid powder. SEM images showed worn regions and wear tracks under different operating environment. Significant improvement in microstructure and wear behavior is observed at lower operating speed of 600 rpm.

An analytical model of Brinell hardness for power-law hardening materials

In the Brinell hardness test a hard spherical indenter is pressed into a metallic material. Due to the inhomogeneous distribution of stresses and strains the hardness measure is not a unique function of the material properties alone, but also depends on the setup geometry notably the diameter of the indenter. To this date there exists no analytic description of these interrelations. Therefore, it seems desirable to derive an analytical model which directly relates the material properties to the hardness value. Based on extensive numerical simulations analytic formulas are derived describing the dependence of Brinell hardness on the applied indentation load. The formulas are capable to represent the entire plastic range relevant for hardness measurements. Based on these results the indentation depths proposed in ISO 6506 can be directly related to a range of force-diameter indices, which serve as a means for selecting the appropriate Brinell test.