Brinell Hardness Research Articles

Enhanced Hardness and Tribological Properties of Copper-Based Steel Backing Self-Lubricating Materials with Y2O3 Micro-Doping

The copper-based steel backing material is prepared using a combination of mechanical alloying and secondary sintering methods. The effect of Y2O3 content on the microstructure, hardness, and tribological properties of the copper-based self-lubricating layer is investigated. The results demonstrate that the addition of Y2O3 enhances the strength of the copper-based self-lubricating layer. Graphite and Y2O3 act synergistically to form a three-dimensional supporting framework, thereby boosting the overall strength of the copper-based composite material and increasing its Brinell hardness by 27%. Additionally, the incorporation of Y2O3 effectively improves the tribological properties of the composite material, significantly reducing wear during the friction process and decreasing the wear rate by 77%. Under the experimental conditions, the optimal Y2O3 content is determined to be 1 wt%.

Evaluating and optimizing metals for kitchen equipment production

This study assesses the mechanical properties and corrosion resistance of three stainless steel grades (316, 201, and 304) used in kitchen equipment manufacturing, emphasizing their performance based on specific metrics. Brinell hardness tests revealed values of 310.13 HB for 316, 286.49 HB for 201, and 276.13 HB for 304. Impact strength and tensile strength tests showed that 316 outperformed the others due to its higher chromium, nickel, and molybdenum content and enhanced mechanical properties from annealing, quenching, and tempering processes. Fatigue strength testing indicated that 316 had the highest endurance strength. Corrosion tests confirmed that all three grades exhibited no corrosion. These results indicate that stainless steel 316 has superior mechanical properties and corrosion resistance, making it an excellent choice for manufacturing durable and reliable kitchen equipment.

Correlation of Solidification Thermal Variables with Microstructure and Hardness in CuMn11Al8Fe3Ni3 Manganese-Aluminum-Bronze Alloy.

The mechanical properties of a final product are directly influenced by the solidification process, chemical composition heterogeneity, and the thermal variables during solidification. This study aims to analyze the influence of solidification thermal variables on the microstructure, hardness, and phase distribution of the CuMn11Al8Fe3Ni3. The alloy was directionally and upward solidified from a temperature of 1250 °C. Heat extraction occurred through a water-cooled AISI 1020 steel interface. The thermal variables were recorded using a data acquisition system, with temperature monitored at seven different positions, where cooling rates varied from 13.03 °C/s at the closest position to 0.23 °C/s at the farthest. The Brinell hardness decreased from 199 HB at the highest cooling rate position to 184 HB at the slowest cooling rate position. This indicates that higher cooling rates increase the hardness of the alloy, which can be attributed to the stabilization of the metastable β phase with refined and equiaxial grains due to iron addition. Vickers microhardness was observed in regions subjected to slower cooling (244 HV) compared to faster cooling regions (222 HV). Therefore, the correlation between solidification thermal variables and alloy properties provides valuable insights into the relationship between microstructure and the properties of the CuMn11Al8Fe3Ni3 alloy.

Implementation of ANOVA and Regression to Optimize Vibratory Stress Relief Parameters in EN 31 Steel to Reduce Residual Stress and Improve Brinell Hardness

Implementation of ANOVA and Regression to Optimize Vibratory Stress Relief Parameters in EN 31 Steel to Reduce Residual Stress and Improve Brinell Hardness

Effects of Magnesium Content and Age Hardening Parameters on the Hardness and Ultimate Tensile Strength of SiC-Reinforced Al-Si-Mg Composites

This study investigates the effects of magnesium (Mg) content, silicon carbide (SiC) reinforcement, and aging temperature (AT) on the ultimate tensile strength (UTS) and Brinell hardness number (BHN) of eutectic Al-Si composites using a full factorial experimental approach. The analysis reveals that increasing Mg content from 0 wt% to 1.5 wt% significantly enhances UTS, likely due to solid solution strengthening and improved particle reinforcement. Similarly, a rise in SiC content up to 4 wt% leads to a notable increase in UTS, indicating effective matrix reinforcement. AT is crucial, with the highest UTS achieved at 100 °C; however, overaging at 200 °C results in reduced strength due to precipitate coarsening. Interaction plots demonstrate a synergistic effect between Mg and SiC, where higher levels of both contribute to a more substantial increase in UTS. The results also show that while both Mg and SiC improve UTS, their effects are optimized with appropriate aging conditions, although overaging diminishes these benefits. Analysis of variance (ANOVA) highlights that AT, Mg, and SiC each significantly impact UTS and BHN, with SiC having the greatest effect of 47.92% on hardness and AT having the greatest effect of 36.58% on the UTS. The interaction between SiC particles and AT is particularly influential on BHN. These findings emphasize the importance of carefully optimizing processing conditions to enhance the mechanical properties of eutectic Al-Si composites.

The Synergistic Effect of Two Alloying Elements on the Microstructures and Properties of Zn–2.5Al–3Mg Alloys

ABSTRACTThe present study investigates the microstructure, hardness, and corrosion behavior of Zn–2.5Al–3Mg alloys with the addition of two elements (Zr–Si, Zr–Sb, and Zr–Ti). This analysis includes SEM/EDS, Brinell hardness testing, electrochemical measurements, and XPS. The SEM results indicate that the Zn–2.5Al–3Mg alloy, with added Zr and Ti elements, exhibits finer grains and a more homogeneous structure compared to the other two combinations (Zr–Si and Zr–Sb). Electrochemical analysis indicated that the Zn–2.5Al–3Mg–0.2(Zr–Ti) alloy exhibited the best corrosion resistance among all the samples tested. Furthermore, XPS identified that the corrosion products of the Zn–2.5Al–3Mg–0.2(Zr–Ti) alloy mainly consist of dense Zn5(OH)6(CO3)2, ZnAl2O4, and MgAl2O4. An exploration into the corrosion resistance mechanism of the Zn–2.5Al–3Mg–0.2(Zr–Ti) alloy showed that the dense corrosion products formed during the corrosion process gradually accumulate and fill corrosion gaps. This accumulation hinders the progression of corrosion into the metal, ultimately enhancing the alloy's corrosion resistance.

Mechanical and chemical characterization of biochar-reinforced polystyrene composites

This study investigates the chemical interactions and mechanical characteristics of composites made of polystyrene reinforced with biochar. Polystyrene-based resin (PBR) was combined with plantain peel-derived biochar in different weight ratios (10%, 20%, 30%, and 40%). The Brinell hardness test, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to evaluate the properties of the composites. The results of the hardness test showed a non-monotonic pattern, with hardness first decreasing at low biochar loadings (10% and 20%), then significantly increasing at 30% biochar. At 40% biochar, the hardness then somewhat dropped, indicating that around 30% filler is the optimal biochar level for hardness. As the biochar loading increased, FTIR measurement showed that hydroxyl groups (-OH) were introduced and that the intensity of carbonyl groups (C = O) increased. According to SEM analysis, a uniform surface was found at lower biochar loadings, but at larger biochar contents, the surface became irregular and rough. In addition to providing insights into the chemical interactions at the interface between the biochar and the polymer matrix, these findings demonstrate the possibility of incorporating biochar to alter the mechanical properties of PBR.

Experimental Investigation of the Effect of Input Control Variables and Thermal Treatments on the Impact Toughness of EN-31 Steel

To meet the engineering applications, mechanical and physical properties of materials especially steels and their alloys are improved through thermal treatments. This research aimed to augment the impact toughness of EN-31 steel by picking the combinations of different levels of Charpy impact test control variables and thermal treatments built in three-level (L9) Orthogonal Arrays (OAs). For this reason, the experimental runs were conducted to examine the influence of varying V-notch angles (30°, 45° and 60°), heights of the hammer (1370 mm, 1570 mm, and 1755 mm), temperatures (-196°C, -50°C, and 28°C), and heat treatments (hardening followed by cryogenic treatment and low-temperature tempering - HCTLTT, hardening followed by cryogenic treatment and medium-temperature tempering - HCTMTT, and hardening followed by cryogenic treatment and high-temperature tempering - HCTHTT) on the impact toughness of EN-31 Steel specimens. Several patterns of thermal treatment sequences were executed with an aim to modify the material properties. Cryogenic treatment (CT) was conducted through a cryocan at 77K. The hardness of specimens were measured by employing a Brinell hardness tester. The results reported that height of the hammer and thermal treatments enhanced the toughness and hardness of the specimens most significantly.

Aspen Wood Characteristics Following Thermal Modification in Closed Process Under Pressure in Nitrogen.

Using a pilot-scale chamber with an interior capacity of 340 L, European aspen (Populus tremula) wood boards were thermally modified (TM) under pressure in nitrogen at a maximum temperature of 160-170 °C, for 60-180 min, and with an initial nitrogen pressure of 4-5 bar. After the TM process, aspen wood was characterised by dimensional changes, mass loss (ML), equilibrium moisture content (EMC), antiswelling efficiency (ASE), cell wall total water capacity (CWTWC), modulus of rupture (MOR), modulus of elasticity (MOE), and Brinell hardness (BH). This work offers fresh insights into the characteristics of aspen wood following a closed TM process in pressurised nitrogen. TM caused ML of 5.4-14.5% and shrinkage in all anatomic directions. The ASE ranged from 22 to 70%, while the CWTWC was reduced from 35% to 11-27%. After treatment, EMC and volumetric swelling (VS) were more than twice as low as in untreated wood. Although MOE values increased and the average MOR reduced following TM, the changes were not important. The TM aspen wood tangential surface's BH dropped and was noticeably lower than the radial surface's BH.

ОСОБЛИВОСТІ СТРУКТУРИ І ВЛАСТИВОСТЕЙ КОМПОЗИТІВ НА ОСНОВІ ПОЛІЛАКТИДНИХ 3Д МАТРИЦЬ І ПОЛІУРЕТАНУ

The peculiarities of the production and structure of combined composites based on polylactide 3D printed matrices and polyurethane resin were investigated. The physical and mechanical properties of the obtained composites were determined depending on the content of modifiers in the polyurethane resin. In particular, an increase in Brinell hardness and impact toughness of products based on 3D matrices filled with modified resin was revealed. The influence of starch and epoxidized soybean oil on Brinell’s hardness and elastic-deformation properties of polyurethane resin was revealed.

Research on Brinell hardness measurement method based on three-dimensional point cloud data

Research on Brinell hardness measurement method based on three-dimensional point cloud data

Effect of heat treatment on the interfacial element diffusion and hardness of FeCoNiCrAl high-entropy alloy coatings

Effect of heat treatment on the interfacial element diffusion and hardness of FeCoNiCrAl high-entropy alloy coatings

Enhanced mechanical properties and wear resistance of thixotropic extruded CuSn10P1 alloys by annealing

Enhanced mechanical properties and wear resistance of thixotropic extruded CuSn10P1 alloys by annealing

Improvement of Hardness on Butt Weld Joints Aluminium Alloy AA 6061 Using the Underwater Friction Stir Weld (UFSW) Method

This study reveals the hardness improvement resulting from Underwater Friction Stir Welding (UFSW) on the butt joint method AA 6061. Underwater welding introduces complexity to the joint's hardness due to the presence of water, which affects the welding process and the quality of the joint formed. The objective of the UFSW study is to explore potential advantages in the aquatic environment, primarily to obtain the optimal machine tilt angle. The study used a conventional milling machine with various spindle speeds, feed rates, and tilt angles to get the best combination of parameters. The spindle speed of 750 rpm, welding speed of 20 mm/min, and machine head angle of 2° recorded show the Brinell hardness (HRB) of UFSW to be 98.8% better than Friction Stir Welding (FSW) on various parameters. This study revealed that a machine tilt angle of 2° increased the hardness of UFSW welding. Theresults show that UFSW can increase HRB through proper head tilt angle, which is even better than the existing method, which is FSW.

Effect of Co Addition on the Microstructure and Mechanical Properties of Sn-11Sb-6Cu Babbitt Alloy.

A Babbitt alloy SnSb11Cu6 with 0-2.0 wt.% Co was synthesized using the induction melting process. This study examined the effect of cobalt (Co) on the microstructure, tensile properties, compressive properties, Brinell hardness, and wear properties of SnSb11Cu6 using optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), a universal tensile testing machine, a Brinell hardness tester, and a wear testing machine. The results indicate that the optimal quantity of Co can enhance the microstructure of the Babbitt alloy and promote microstructure uniformity, with presence of Co3Sn2 in the matrix. With the increase in Co content, the tensile and compressive strength of the Babbitt alloy first increased and then decreased, and the Brinell hardness gradually increased with the increase in Co content. The presence of trace Co has a minimal effect on the dry friction coefficient of the Babbitt alloy. When the Co content exceeds 1.5 wt.%, the friction properties of the Babbitt alloy deteriorate significantly. The optimized Babbitt alloy SnSb11Cu6-1.5Co was subsequently fabricated into wires, followed by conducting cold metal transfer (CMT) surfacing experiments. The Co element can promote the growth of interfacial compounds. The microstructure at the interface of the Babbitt alloy/steel is dense, and there is element diffusion between it. The metallurgical bonding is good, and there are serrated compounds relying on the diffusion layer to extend to the direction of the additive layer with serrated compounds extending and growing from the diffusion layer to the additive layer. Overall, Babbitt alloys such as SnSb11Cu6 exhibit improved comprehensive properties when containing 1.5 wt.% Co.

The Influence of Er and Zr on the Microstructure and Durability of the Mechanical Properties of an Al-Mg Alloy Containing 7 wt.% of Mg.

Al-Mg alloys are characterized by permanent solid solution hardening and can additionally be work-hardened. The high mechanical properties of Al-Mg alloys with above-standard Mg content obtained after plastic deformation processes decrease over time. The addition of minor alloying elements like Er or Zr is an alternative method to improve the durability of mechanical properties and increase the strength of Al-Mg alloys due to densely and evenly distributed dispersoids being formed. In this paper, Al-Mg alloys with above-standard Mg content (7 wt.%) and Zr and Er micro-alloying elements and their influence on the microstructure and durability of the mechanical properties were examined. The cast ingots of AlMg7 alloys were characterized by a smooth surface without cracks. The plastic deformation process in a static compression test resulted in an about 60 HBW increase in the Brinell hardness of all the deformed alloys relative to casting. It was revealed that the addition of Er and Zr significantly improved the mechanical properties and durability of the mechanical properties of the Al-Mg after annealing. The addition of Er or Zr slightly restrained the decrease in the Brinell hardness after annealing but did not inhibit it.

Mechanical and micro-structural characterization of biodegradable coir fiber–glass sheet–charcoal reinforced polymer composite: an experimental approach

In the present investigation, the combined influence of coir, glass fibers and charcoal content on the mechanical properties of epoxy-based hybrid composites has been explored, providing insights for the potential development of advanced materials with tailored performance characteristics. Through a systematic analysis of the mechanical properties (tensile strength, Young's modulus, flexural strength, flexural modulus, and Brinell hardness number), various composite formulations were evaluated to discern their performance characteristics. The study reveals significant variations in mechanical properties across different composite configurations, highlighting the critical role of fiber type and charcoal content in determining the materials’ performance. Notably, composites featuring alternating layers of glass and coir fibers exhibit superior tensile and flexural strengths, underscoring the synergistic effects of hybridization. Conversely, the introduction of charcoal as a reinforcement agent leads to deterioration in the mechanical properties, indicating a trade-off between the reinforcement and other desirable attributes. These findings offer valuable insights for the strategic design and engineering of advanced materials tailored to specific applications, paving the way for the development of high-performance epoxy-based hybrid composites with enhanced mechanical properties and durability.

Evolution of Microstructural and Mechanical Properties of Alloy 617B During Service on a Key-Component Test Platform at 700 °C.

The evolution of the microstructural and mechanical properties of alloy 617B during long-term service on a key-component test platform at 700 °C was systematically investigated. The precipitation behavior and size changes of the M23C6 and γ' phases were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that carbide M23C6 precipitated in the form of discontinuous particles, plates, or needles at grain boundaries and within grains, while the γ' phase had a spherical shape and was distributed in a dispersed manner. With prolonged service time, both the M23C6 and γ' phases gradually coarsened. After 24,000 h of service, the yield strength, tensile strength, and Brinell hardness of alloy 617B significantly increased; however, the impact toughness decreased, accompanied by intergranular embrittlement. The increase in precipitate volume fraction and its contribution to the strength of the alloy were evaluated by a precipitation strengthening model. The coarsening of M23C6 was identified as the main cause of embrittlement. The findings of this study provide important experimental data and theoretical support for the stability of 617B alloys under long-term high-temperature service conditions.

Development and characterization of sustainable epoxy resin composites reinforced with palm kernel shell particulate and sisal fiber

This study explores the development and characterization of epoxy resin composites reinforced with palm kernel shell (PKS) particulate and sisal fibers, aiming to create sustainable and high-performance materials. Elemental composition analysis using energy dispersive X-ray revealed significant increases in carbon and oxygen content with higher PKS particulate content, indicating successful reinforcement integration. The mechanical properties were evaluated through Brinell hardness, impact energy, impact strength, tensile stress, and wear resistance tests. The Brinell hardness increased from 31.8 kg/mm2 in the control sample to a peak of 60.6 kg/mm2 in sample SP4, demonstrating enhanced hardness with PKS particulate addition. Impact tests identified an optimal reinforcement level in sample SP3, which achieved the highest impact energy (83 J) and impact strength (47.43 kJ/m2). Tensile stress analysis showed a maximum tensile stress of 28.7991 MPa for SP3, while excessive PKS content in SP4 reduced this to 20.4612 MPa. Wear tests indicated a trade-off between mechanical reinforcement and wear resistance, with the control sample exhibiting the lowest wear rates and SP4 the highest having a 91.9% increase. Based on the obtained results, SP3 with 0.8 g PKS particulate, 0.2 g sisal fiber in epoxy resin matrix seems the optimized composite with enhance mechanical properties without compromising wear resistance.

Study on Mechanical and Microstructural Evolution of P92 Pipes During Long-Time Operation

To investigate the mechanical properties and microstructure evolution of P92 steel during long-term service, the operated P92 main steam pipes from the first ultra-supercritical units in China were sectioned into samples representing various service durations and stresses (0# (as-received state, 1# (82,000 h, 67.3 MPa), 2# (85,000 h, 78.0 MPa), and 3# (100,000 h, 80.3 MPa)). Thereafter, a comprehensive assessment of their mechanical properties, including tensile strength, impact, hardness, and creep resistance, as well as a detailed microstructure analysis, was carried out. The effect of stress on the aging of material properties during operation is discussed. The results show that the circumferential stress caused by the increase in the internal steam pressure can significantly promote the creep life consumption of P92 steel, resulting in the degradation of mechanical properties and the expedited aging of the microstructure. The Rp0.2 and Rm of the P92 main steam pipe at room temperature and 605 °C decreased with the service time increase, reflecting the influence of stress in operation, which is expected to be used for the residual life evaluation of P92 steel. The relationship between the impact absorption energy (FATT50), Brinell hardness, and the operating time of P92 operating pipes is non-monotonic, indicating that these parameters are not sensitive indicators of material aging due to stress. The evaluation of performance degradation in P92 operating pipes due to stress-induced aging is not reliably discernible through optical metallography alone. To achieve a thorough assessment, the use of transmission electron microscopy (TEM) is essential.