Brinell Test Research Articles

Investigation of the microstructure, electrical and mechanical properties of Al-CNTs-B4C composite prepared by double-step stir casting for power transmission conductor

Abstract Monolithic aluminium alloy is a modern engineering material that is in high demand owing to its excellent performance and versatility. It has a high electrical conductivity, low density, high strength- to- weight ratio, and high resistance to corrosion. However, it lacks adequate resistance to creep, fatigue, stable microstructure, and strength at elevated temperatures. To overcome these deficiencies, aluminium matrix composites are developed. This work focuses on an experimental investigation of the microstructure, mechanical strength, and electrical conductivity of Al-CNTs-B4C composite consolidated by a double-step stir casting technique. An x-ray diffractometer, transmission electron microscopy, and a field-emission scanning electron microscope fitted with energy dispersive x-ray spectroscopy were used to characterize the start-up powders and the cast samples. A Brinell tester was used to measure the microhardness of the cast samples. A four-point probe meter was used to determine the electrical conductivity. The microstructural results revealed formation of Al4C3 and Al3BC intermetallics, B4C phase and amorphous carbon precipitate. Marginally improved electrical conductivity of 33.33 × 107 S m−1 (65.1% IACS) was obtained with Al-5CNTs-15B4C, together with high microhardness of 725.72 MPa. The microhardness improved by 94.7% over monolithic pure Al. The double-step stir casting enhanced the homogenous dispersion of the reinforcements. The improvements in the mechanical properties and electrical conductivity were attributed to the synergy between B4C and CNTs which induced Orowan looping, load transfer effect, plastic deformation and dislocation pinning in the composite. It is recommended that this composite will perform creditably in power transmission.

Modification of the Structure and Mechanical Properties of Cu-30%Zn alloy with Cerium and Silicon

This study investigates how the introduction of cerium and silicon influences the structure and mechanical characteristics of Cu-30%Zn alloy. The examined properties included tensile strength, hardness, and impact resistance. The tensile strength of the developed alloys was determined using an automated JPL tensile strength tester (Model: 130812) with a capacity of 100 kilonewtons, following the ASTM D638 standard. The impact strength was assessed by the ASTM D256 standard using a pendulum impact testing machine (Model: U1820). Additionally, hardness testing was conducted using a Brinell tester. The Brinell hardness test was performed with a portable dynamic hardness tester (Model: DHT-6) by the British Standard (BS EN ISO 6505-1:2014). Specimens were prepared by incorporating cerium and silicon into the Cu-30%Zn alloy at concentrations of 0.1wt%, 0.3wt%, 0.5wt%, 1.0wt%, 3.0wt% 5.0wt% ranging from 0.1% to 5.0%, with increments of 0.2% for micro addition and 2.0% for macro addition. Microstructural analysis was performed using an L2003A reflected light metallurgical microscope. Scanning Electron Microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also utilized to characterize the cast specimens. The findings revealed a proportional increase in tensile strength, impact strength, and hardness strength with the rise in dopant concentrations up to 3.0wt% for cerium and silicon. Also, the analysis uncovered the presence of. primary α-phase, β-phase (intermetallic phases), and fine stable phase. These phase modifications contributed to the enhancement of mechanical properties. Cu-30wt%Zn enriched with 3.0% cerium and silicon demonstrated heightened tensile strength, impact strength, and hardness, making it a recommended choice for engineering applications.

Effect of various disinfectant solutions on the tensile strength of gutta-percha using the rapid sterilization technique.

Gutta-percha (GP) gets contaminated during handling. It becomes imperative to ensure GP is sterile before placement in root canal space. The aim of the study was to evaluate and compare the tensile strength of GP treated with four different disinfectant solutions: 3% sodium hypochlorite (NaOCl), amla juice (AJ), Aloe vera (AV) juice, and pancha tulsi (PT). The study design was an in vitro study. Fifty GP cones with a size of 30 were procured from sealed packages in five different groups. Experimental groups were disinfected for 1 min with 3% NaOCl, AJ, AV, and PT except the control group. Tensile and Brinell Testing Machine is used to measure the tensile strengths of GP. Results were subjected to statistical analysis using the Kruskal-Wallis test followed by Dunn's post hoc test. The mean tensile strength values for Groups A, B, C, D, and E are 9.49 Mpa, 13.33 Mpa, 12.58 Mpa, 12.69 MPa, and 13.56 MPa, respectively. In the herbal disinfectant group, such as AJ, AV, and PT, the tensile strength was not significantly altered, whereas in the 3% NaOCl group, it was reduced considerably. AJ, AV juice, and PT as a GP disinfectant do not alter the tensile strength of GP cones.

Hardness determination by a semi-automatic testing system

The hardness testing is vital for metals for testing and production quality control. Hardness testing is a fine indicator to determine the mechanical characteristics of metals. The various types of hardness testing methods include Rockwell, Vicker, Brinell, and Knoop testing methods. The most prevalent manual method to determine hardness is indentation using dead weight technology. However, the said technology is quite ancient and it has its own limitations, like the kinetic effect applying excessive load at actual, man-to-man variations, variation over the period due to deterioration and friction effects of moving parts like lever, weight block hanger, etc. increases the uncertainty of this method and eventually demands for upgradation of the technology. Further, the methods currently in use are open-loop and manually operated testers. The main drawback of all these testers is that they provide zero feedback, and so the obtained result needs to be compared to the desired result. To overcome the above-stated problem, the paper presents some novel modifications for measuring hardness using existing methods of Rockwell, Vicker, and Brinell testing. Toward this objective, the paper proposes to modify existing testers and develop a semiautomatic hardness testing system. Firstly, for Rockwell testing, the work aims to design a closed-loop system for hardness testing. The proposed system comprises of Arduino as an open microcontroller, a load cell along with servo motor, and its driver to establish the desired closed loop. The need of obtaining a more accurate result, free from human interference gives rise to a closed-loop system for hardness testing. The key aspect of the closed-loop system lies in retaining the basic structure of the metal. Unlike traditional hardness tester, during testing, the weight increases gradually, due to which the basic structure of metal is not deformed. Secondly, the paper proposes a computational methodology that would estimate the Vickers and Brinell hardness value. The proposed system comprises of a camera for gathering hardness indentation images, thereby automating the system. Further, these images are analyzed based on image processing software, and the indentation depth is obtained. The proposed work thus replaces human intervention to calculate the hardness of the material. The results obtained based on the proposed systems provide a proof of concept to address the problems of traditional Rockwell, Vicker, and Brinell testing.

The Influence of Strontium Oxide on the Physio-Mechanical Properties of Biomedical-Grade Titanium in Ti-SrO Composites

Dental implants can be made of various materials, and amongst them, titanium and titanium alloy were the materials of choice for dental implants for many years because of their biocompatibility. The two alloys have a high level of biocompatibility, a lower modulus of elasticity, and better corrosion resistance than other alloys. Thus, they are frequently utilized in biomedical applications and mostly replace stiff fabrics. The latest advances in a new strontium oxide–cp titanium composite alloy are the main topic of this research. With regard to biomedical applications, additions of strontium oxide were synthesized at three distinct weight percentages (2%, 4%, and 6% by wt%). Powder metallurgy was used to create the alloys, which were then sintered by heating the samples. The effects of adding strontium oxide were analyzed by utilizing measurements of the Brinell hardness, X-ray diffraction, porosity, diametral tensile strength, roughness, and wettability of the finished surfaces. The results show that adding more strontium oxide (gradually increasing the ratio from 2% SrO to a 6% addition) raised the roughness and porosity. However, the microhardness and diametral tensile strength were enhanced with an increase in the volume fraction of strontium oxide particles. In conclusion, the alloy that contained 6 wt% strontium oxide microparticles had reasonably high mechanical properties and might be regarded as suitable for use in dental and medical applications due to its high wettability or, in other words, its low contact angle. The Brinell testing results for the diametral tensile strength, microhardness, and porosity of the generated strontium oxide–cp titanium composite alloy demonstrate its high potential for usage as a biomaterial, particularly in dental applications.

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.

Pengaruh variasi laju aliran dan preheating cetakan pada investment casting terhadap sifat fisis dan mekanis prototipe aluminium cylinder head engine

This research studies the effect of flow rate on the pouring of molten metal into the mould so that the flow rate into the mould can be controlled. Furthermore, this research studies the effect of mould preheating so that the temperature inside the cavity can be maintained, especially for narrow holes. The process starts with making the engine cylinder head pattern and gating system using a three-dimensional printer with polylactic acid resin. The mould pattern and gating system are combined and coated with a layer of cement plaster, silica sand and kaolin. After the coating is dry, the mould is heated until the mould pattern evaporates and there is no residue. The casting process was carried out at pre-heating moulds of 300 0C and 350 0C and a pouring temperature of 800 0C with pouring speeds of 20, 30, and 40 rpm. The final stage of the research is manufacturing test objects and testing mechanical properties. The results showed that the higher the pouring speed, the less perfect the casting results, especially in the cylinder head fins. The best casting results occurred in the pre-heat condition of the 300 0C mould with a pouring speed of 20 rpm, with a Maximum Tensile Strength of 105 N/mm2, Hardness 53 hardness Brinell test (HBN), Density and Porosity of 2.43 gr/cm3. The material used in this study refers to the reference is A356 Aluminum Alloy.

Secondary Material Casting of Al-Si for Making Handle Brake in Variation of Duct

This study aims to determine the effect of the mold casting duct variations on shrinkage, porosity defects, density, hardness, and chemical composition of materials. The primary raw material uses melting secondary aluminium through a small-scale smelting furnace. Research study about three kinds of ducts: triangular duct, rectangular duct, and circular duct. The testing chemical composition uses an emission spectrometer. Research founds defects by comparing the dimensions of the original object with the specimen results of each duct variation. The density value calculates porosity defects. ASTM E10 standard Brinell test measures the hardness. Besides, ASTM E3 standard test quantifies the microstructure of the product. The highest average shrinkage is the triangular ducts at 3.68%. The least significant numbers of porosity were in rectangular ducts of 2.964 gr/ml. Higher the density value, the denser the material, and the more negligible the porosity. The density of the material affects the hardness material obtained from the results of the Brinell test. The hardness of the Brinell test brought that the rectangular duct with 102.5 BHN was the most enormous. In addition, the results showed that the chemical composition mainly contained mostly chemical elements (Al) 87.1% as the main chemical ingredient and (Si) 9.51%.

Physical, Rheological, And Microsurface Characteristics of High-Viscosity Binder Modified with WMA Agents

In order to investigate the feasibility of warm mix technology in high-viscosity asphalt mixes, in the current experiment, Shell 70 Grade A asphalt (base asphalt) was modified by AR-HVA (a high-viscosity modifier), and the high-viscosity modified asphalt was further incorporated with two surface-active warm mixes (Evotherm M1 and Retherm). The physical properties of the high-viscosity warm mix-modified asphalts were analyzed by dynamic and Brinell viscosity tests. The compatibility of the warm mixes with the high-viscosity modified and the base asphalt was analyzed by fluorescence microscopy. The modification mechanism of the high-viscosity warm mix-modified asphalts was revealed by Fourier-transform infrared spectroscopy. The high-viscosity modifier significantly reduced the penetration of the matrix asphalt and increased its softening point and 5°C ductility, whereas the two warm mixes increased the penetration and ductility of the high-viscosity modified asphalt and reduced its softening point. The surface-active warm mixes reduced the 60°C viscosity of the asphalt, and the viscosity reduction effect of M1 was better than that of Retherm. The high-viscosity modifier AR-HVA was well dispersed in the asphalt; however, its continuity was not good. The addition of the surface-active warm mixes effectively enhanced the continuity of the high-viscosity AR-HVA-modified asphalt. Infrared spectroscopy revealed little difference between the main components of the matrix asphalt and the high-viscosity asphalt. The addition of the surface-active warm mixes altered the amounts of four components in bitumen and increased its aromatic content.

PREDIKSI NILAI BATAS ELASTISITAS BAJA KONSTRUKSI DENGAN UJI KEKERASAN BRINELL DAN VICKERS


 
 
 This study aimed to determine the correlation value against the value of hard carbon steel with elasticity it. This is done by determining the formula formulation in the form of the regression equation Y = AX1 + BX2. Data taken from the sample used in the form of a cylindrical rod test specimens and the steel plate. Severity using the Brinell test, whereas withdrawal using tensile testing machine. The results were obtained for cylindrical steel Y = 2,41 X1 – 0,4347X2 and for specimens of steel plate (flat) Y = 2,35 X1 – 0,534X2. Y is the value of the rigidity, and X1 is hardness of steel. While X2 arises from material stretch factor. Probability influence of workmanship and style fluctuate respectively 0,4347 and 0,534 is much larger than 0.05 (a standard which is commonly used). This means that the regression coefficient is not significantly different effect. Decrease in strength may be due to the loss of influence of the stress concentration occurs. In addition it could also be due to the configuration of the carbon forming constituents uneven in areas experiencing strain due to the with drawalprocess
 
 

Heat treatment of high-pressure die casting Al-Mg-Si-Mn-Zn alloys

The microstructure and mechanical properties of Al-5.7Mg-2.6Si-0.7Mn-xZn high-pressure die casting alloys after heat treatment have been investigated. The microstructure was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The hardness was determined by Brinell and Vickers testing. The effects of T5 (artificial ageing from the as-cast state) and full T6 heat treatment modes on the alloys with different Zn content (0.6–5 wt%) on the microstructure and mechanical properties were investigated. The solution treatment changes the microstructure of the studied alloys. The T-AlMgZn phase dissolves into the α-Al phase during solution treatment at temperatures higher than 375 °C. Artificial ageing at 125–225 °C does not lead to any changes in the microstructure of alloys, however, leads to the formation of several types of Zn-containing precipitates in the α-Al. The optimal temperature for artificial ageing from the as-cast state as well as after solution treatment is in the range 125–175 °C for 2–5 h. It was found that the most noticeable changes in the mechanical properties were achieved in the alloys with 1.2–1.8 wt% Zn. It was found that these changes are associated with Zn distribution, the morphology of the phases and the formation of nano-sized precipitates in α-Al solid solution.

Brinell indentation behavior of the stainless steel X2CrNi18-9: Modeling and experiments

Stainless steel X2CrNi18-9 plays an important role in many industrial fields, namely in the agro alimentary industry based on its corrosion resistance. Meanwhile, its mechanical and tribological resistance still presents a challenge. In the olive oil extraction industry, the stainless steel X2CrNi18-9 presents a complex damage mechanism under concentrated load. In the present study, a Brinell indentation test was carried out on the stainless steel X2CrNi18-9 under a load range between F = 10 N and F = 613 N. A three-dimensional finite element (FE) model has been elaborated in order to simulate and understand the mechanical response under this specific concentrated load given by the Brinell test. The mechanical behavior of stainless steel has been described by the Johnson-Cook elasto-plastic model and its damage mode by the Johnson-Cook failure model. The main experimental and numerical results show a stress concentration in the border and in the center of the indents throughout the indentation tests caused by the plastic deformation. The SEM investigations show typical indents increasing in size with increasing load and a pile-up phenomenon as a result of a large E/Y ratio (Young's modulus/yield stress). The elaborated FE numerical model of the Brinell indentation test shows a very satisfactory correlation to the experimental test results.

Effect of Zr, Cr and Sc on the Al–Mg–Si–Mn high-pressure die casting alloys

New aluminium Al5Mg2SiMn casting alloys with Sc, Cr, Zr addition have been developed. The effect of the alloying elements in amount of 0.1 and 0.2 wt% on the microstructure and mechanical properties of the Al5Mg2SiMn casting alloy produced by the HPDC was investigated. The microstructure was observed by means of the scanning electron microscopy and electron probe microanalysis. The hardness of the aforementioned alloys was determined by Brinell and nanoindentation testing. The microstructure of the HPDC aluminium alloys consists of primarily α-Al phase, the α-Al15(Mn,Fe)3Si2 intermetallics and Al–Mg2Si eutectic cells. Coarse Al7Cr as well as Al3Zr intermetallic phases in the alloys with Cr and Zr addition were observed. The most significant improvement in the mechanical properties was achieved in the alloys with Sc addition. Alloying with 0.2 wt% of Sc exhibits the best combination of strength and ductility with a yield strength of 196 MPa, an ultimate tensile strength of 341 MPa and 10 % of elongation in the as-cast condition. Alloys with Cr and Zr additions present the similar properties in terms of hardness compared to the alloys with Sc addition and the similar tensile properties comparable to the AlMg5Si2Mn (commercially known as “Magsimal-59”) base alloy.

Rockwell Hardness Testing of Pure Nickel Collimators for BNCT Application

In this study, Rockwell and Brinell hardness testing was used to examine material hardness. These methods were chosen because they are easy to carry out, relatively inexpensive, and almost all sizes and shapes can be tested, in which nickel hardness before and after centrifugal casting are identified and compared. These tests enable the determination of the hardness numbers of nickel collimators using for boron neutron capture therapy. The samples were five nickel plates with a dimension of 4.5 × 4.5 cm and five collimators. The collimators were cylindrical and made using centrifugal casting. The basic principle of the hardness test was to apply loading on the object being tested. The Rockwell test was used to assess the material's hardness from the difference of indentation depth, while the Brinell test was used to determine the hardness from the diameter of indentation. From the results of this test, the hardness number of nickel before centrifugal casting is 168.53 BHN or 86.13 HRB, while the hardness number after centrifugal casting is 115.68 BHN or 64.84 HRB. It can therefore be concluded that centrifugal casting decreased nickel hardness.

Parametric Investigation of Squeeze Casting Process on the Microstructure Characteristics and Mechanical Properties of A390 Aluminum Alloy

Effects of squeeze casting (SQC) parameters, including squeezing pressure, superheats of liquid metal and die preheating temperature on microstructure characteristics and mechanical properties of A390 aluminum alloy, were evaluated using L9 design based on Taguchi method. Squeeze casting was performed by a 25-ton hydraulic press, and all of the parameters were evaluated at 3 different levels: the squeezing pressure was at 60, 90 and 120 MPa, the superheat of the liquid metal was at 50, 100 and 150 °C and the die preheating temperature was at 200, 250 and 300 °C. The microstructure characterization was also performed using optical microscopy image analysis and scanning electron microscope (SEM). Tensile and Brinell test methods were applied for measuring ultimate tensile strength, yield strength, elongation and hardness. The results showed that the SQC process modified cast microstructure and improved mechanical properties of the alloy. In addition, the variations of the SQC parameters, specially the squeezing pressure, have significant effects on the size and volume fractions of the primary silicon, eutectic cells and the mechanical properties. According to the results, increase in squeezing pressure from 60 to 120 MPa within the tested range leads to primary silicon area decrease by 48% and silicon eutectic decrease by 44.4%; however, applied pressure did not have any significant effects on morphology of phases. On the other hand, superheating over 100 °C and die preheating at 200 °C had significant effects on the final result. It is clearly observed that rising pressure to 90 MPa consequently increases the tensile strength, elongation and hardness. But increasing the pressure to over 90 MPa did not have any significant effects on the final result.

Indentation modulus at macro-scale level measured from Brinell and Vickers indenters by using the primary hardness standard machine at INRiM

In this paper, the experimental procedure and calculation model for the measurement of the indentation modulus by using the primary hardness standard machine at INRiM in the macro-scale range at room temperature is described. The indentation modulus is calculated based on the Doerner-Nix linear model and from accurate measurements of indentation load, displacement, contact stiffness, and hardness indentation imaging. Measurements are performed with both pyramidal (Vickers test) and spherical indenters (Brinell test). Test force is provided by a dead-weight machine, and the occurring displacement is measured by a laser-interferometric system. The geometrical dimensions of both the Vickers and Brinell indentations are measured by means of a micro-mechanical system and optical microscopy imaging techniques. Applied force and indentation depth are measured simultaneously, at a 16 Hz sampling rate, and the resultant loading-unloading indentation curve is obtained. Preliminary tests are performed on metal and alloy samples. Considerations and comments on the accuracy of the proposed method and analysis are discussed.

Effect of Holding Time and Cooling Medium on Microstructure and Hardness of AISI 8655 in Hardening Process

Abstract ¾ The microstructure transformation of AISI 8655, affecting to hardness and impact properties in various hardening processes, has been investigated in this work. AISI 8655 specimens which had been prepared before hardening processes were heated to austenite temperature and held for 30 minutes and 60 minutes then continued by rapid cooling in various medium (air, oil and water). The hardened steel specimens were tested by optical microscope to observe microstructure, brinell test and impact test respectively to measure hardness and impact strength properties. Martensite and bainite were microstructures that appeared after hardening processes. The holding time for 30 minutes gave higher hardness properties than the holding time for 60 minutes. However, the holding time for 60 minutes performed higher impact strength than that for 30 minutes. The highest of hardness was performed by the specimen cooled in water medium at 552 BHN and the highest of impact strength was performed by the specimen cooled in air medium at 7.2 J/mm 2 .

Experimental and Numerical Investigation of the Recrystallization on a Sheet of Wrought Aluminum Alloy Al 6061

Abstract Apart from temperature and time, the deformation introduced in the material is another important parameter that affects the recryristallization process in metallic materials. The present study aims at examining the impact of the introduced deformation on recystallization and grain growth in Al 6061 alloy sheet. The deformation was introduced by hardness indentations in accordance with the Brinell test method applying two different loads. The samples with the hardness indentations were cut in half along the line on which the indentations were performed. One half served as sample providing a reference condition, while the other half was recrystallized. The grain size and the degree of misorientation (Kernel Average Misorientation, KAM) of the two neighboring measurement points were evaluated in both halves of the samples. Using the FE method, the hardness measurement procedure could be numerically simulated and the deformations which occurred beneath the hardness indentations could be evaluated and associated with experimental findings related to the grain size and the misorientation.

The Effect of SiCp Addition on Corrosion and Wear Behavior of Conventionally and Microwave Sintered PM 316L

In this study, corrosion and wear behaviors of PM 316L matrix composite materials reinforced with SiC particles in amounts of 10 vol% are evaluated. The samples are uniaxially cold pressed, and then sintered by two different methods, conventional sintering and microwave sintering. Corrosion properties are evaluated by both immersion and cyclic polarization tests. Wear properties are evaluated by dry sliding wear tests. Brinell and Vickers microhardness tests are applied, in order to support the wear test results. The results show that 10 vol% SiCp reinforced composite samples have acceptable corrosion properties and improved wear resistence in a similar manner, as they show good mechanical properties. In addition, microwave sintering results in better wear properties compared to conventional method.

Experimental characterization of the mechanical properties of railway wheels manufactured using class C material

The railway system has an important role in developed countries: it is possible to see, nowadays, passenger trains crossing the Old Continent and achieving impressive speeds in the East; at the same time, cargo wagons are hitting load-by-axle records in North America. Railway wheels are a critical component to this system, as any failure can lead to derailment, potentially causing financial loss and/or fatal accidents. The present work aims to analyze the mechanical properties of forged wheels manufactured according to the American standard AAR class C, usually applied in freight cars due its chemical composition (around the eutectoid point) which achieves high mechanical resistance combined with moderated toughness. The mechanical tests to evaluate the mechanical strength, ductility, toughness and hardness were performed in accordance with the European standard BS EN 13262, as follows: tensile tests at different temperatures, impact tests, toughness tests and hardness Brinell tests. The obtained results are in accordance with the microstructure and chemical composition of class C material, and will be employed in future investigations for the numerical validation of the mechanical behavior for multiaxial fatigue conditions and development of new materials (micro alloyed steel).