Effect Of Boron Addition Research Articles

Effects of boron addition on the microstructure and creep properties of a Ni-Fe-based superalloy weld metal alloy

The role of boron in the creep properties and grain boundary characteristics in a new Ni-Fe-based weld metal suitable for advanced ultra-supercritical (A-USC) coal-fired power plant applications has been investigated. Ni-Fe-based filler wires without boron and boron-doped (50 ppm wt% boron) were prepared for this study. Boron-doped weld metals exhibited longer rupture lives and lower steady creep rates during the creep rupture tests at 750 °C / 380 MPa and 750 °C / 210 MPa. This study explains the improvement mechanism of boron on creep resistance from the perspective of the effect of boron on M23C6. Boron increased the nucleation rate of M23C6 and participated in the formation of M23(C, B)6 type boron-carbides. After creep deformation, boron still existed stably in the M23(C, B)6. The higher density of discrete M23C6 particles due to boron addition could restrain grain boundary crack propagation and grain boundary sliding, and thereby improve the creep fracture resistance of the GH984G weld metal at 750 °C / (380/ 210 MPa).

Effect of boron addition on the gear fatigue strength of Fe-Ni-Mo-B-C sintered alloys

Effect of boron addition on the gear fatigue strength of Fe-Ni-Mo-B-C sintered alloys

Analysis of the effect of boron addition on steels for forged components

Following the high cost of Mo and other alloying elements, many attempts are being carried out aimed to improve the hardenability of high thickness forged components without increasing their price. In this work the effect of B is examined on laboratory scale. In particular, two ingots have been cast in a pilot plant, with boron addiction. Boron as been added in a protected steel chemical composition, so to be effective in terms of hardenability. Materials were then hot rolled and cooled favoring the formation of a microstructure typical of that of forged components. Results on the material are compared to that of a standard steel in terms of hardenability. Copyright © 2018 VBRI Press.

Effect of boron addition on three-body abrasive wear characteristics of high chromium based multi-component white cast iron

This study aims to systematically investigate the influence of boron (0–3.0 wt % B) on microstructure and abrasive wear characteristics of high chromium based multi-component white cast iron (Hi-Cr MWCI).As result, the microstructure is mainly composed of martensite matrix and carborides such as M7(C, B)3, M2(C, B), M23(C, B)6. At low load, B can increase the wear resistance of Hi-Cr MWCI owing to the higher volume fraction of M2(C, B). However, it reduces the wear resistance of material due to low the fracture toughness of primary M7C3 or M7(C, B)3 at high load. Therefore it can be concluded that B addition can improve the abrasive wear resistance of Hi-Cr MWCI at low load, but, the opposite tendency will occur at high load.

The Effect of Boron Addition on the corrosion behavior of Ni Cr Modental alloy prepared by powder metallurgy.

The powder metallurgy (PM) method was used to create the alloy. The sintering process was carried out in an inert high-temperature tube furnace in the presence of inert gas at a temperature of 1000 ° C for 8 hours (Argon). In this article, the effect of (B) at three wt.% (0.4,0.8,1.2) on the corrosion rate, hardness, and microstructure of alloys was examined. X-ray diffraction (XRD), open circuit potential, electrochemical tests (Tafel extrapolation method), and Macro hardness Brinell were used to study the effect of adding (B) in various amounts to alloys. Saliva was utilized as the corrosion solution for the testing. The inclusion of the alloy element (B) increased hardness and a decrease in particle size, as seen by the microstructures. Furthermore, the corrosion resistance of the master alloy improved next the addition, as shown by Corrosion potential has increased while corrosion current densities have decreased. The corrosion rate for A, A1, A2 and A3 was 14.50, 7.42, 2.03and 2.77 (mpy) respectively.

Effect of boron addition on the microstructure and mechanical properties of refractory Al0.1CrNbVMo high-entropy alloy

The effect of boron (B) addition on the microstructure and mechanical properties of a refractory high-entropy alloy (RHEA) was investigated. The Al0.1CrNbVMo RHEA was doped with 0.015 at.% of B by the powder metallurgical process, and its mechanical properties were compared with undoped RHEA. The microstructures of the undoped and doped RHEAs consisted of a single body-centered cubic matrix phase with homogeneously distributed Al2O3 inclusions. The doped B atoms segregated along grain boundaries and did not form any boride phases. Boron segregation at the grain boundaries was characterized by atom-probe tomography. Compared with the undoped RHEA, the B-doped RHEA showed improved yield strength of 2933 MPa (15% improvement) and ductility of 25.9% (26% improvement). Adding B transformed the fracture surface from intergranular to transgranular due to enhanced grain boundary cohesion induced by B segregation, which resulted in improved ductility. Quantitative analysis was conducted on the undoped and doped alloys to investigate the effect of B on yield strength. The improved yield strength resulting from B doping was attributed to the combined effects of Orowan, dislocation, and B interstitial strengthening. This work demonstrates that B doping of RHEAs is a promising way to overcome their limited room temperature ductility, while maintaining excellent strength.

Tribological Performance of CoCrMo Alloys with Boron Additions in As-Cast and Heat-Treated Conditions

The present study evaluates the effect of boron additions on the tribological performance of CoCrMo alloys. The alloys were prepared with boron ranging from 0.06 to 1 wt%. The materials were characterized using metallographic techniques, scanning electronic microscopy, and roughness and hardness tests. Tribological evaluation was made by means of ball-on-disc tests for sliding distances of 4, 8 and 12 km. The samples were in the as-cast condition and after a heat treatment at 1200 °C for 1 h, finished by water quenching. The results showed that wear resistance was influenced by the microstructure and the number of secondary phases. The volume loss decreased as the boron content increased. Due to hard phases, abrasion wear was observed. Delamination fatigue was also detected after long sliding distances. Both wear mechanisms diminished in higher boron content alloys.

Effect of boron addition on fluorine doped ZnO particles

Effect of boron addition on fluorine doped ZnO particles

Combustion performance with ap and boron addition in staged hybrid rocket

This study investigated the effect of ammonium perchlorate (AP) and boron addition on controllability of the combustion temperature in fuel-rich effluent and system specific impulse. In addition, a series of combustion tests was carried out to analyse and evaluate the effect of boron addition on fuel regression rate and radial temperature profiles. To keep the hybrid rocket engine advantages, upper limit of AP and boron contents in solid fuel was set to be 15 and 10wt% respectively. The results suggested that AP addition proved to be very effective in controlling the effluent temperature. Not only that, it also offers less injected oxidizer mass flow, and resulted in less O/F variation, and less combustion pressure while producing the same combustion in temperature fuel-rich effluent. With boron addition, it also provided more uniform radial temperature distribution. Also, boron addition increased specific impulse by 6.8-13.7%. Secondary combustion using different solid fuels showed a decrease in c* efficiency with increasing boron content in solid fuel. Combustor length and combustion pressure were introduced to improve the combustion of boron particles, however, combustion efficiency was decreased with increasing combustion pressure and combustor length for given test conditions.

Effect of boron addition on microstructure, hardness and wear performance of Ti-6Al-4 V alloy manufactured by laser powder bed fusion additive manufacturing

In the present work, the effect of the addition of elemental boron in Ti-6Al-4V alloy powder for in-situ fabrication of TiB/Ti-6Al-4V nanocomposites using laser powder bed fusion (L-PBF) technique with commercial processing parameter of EOSINT 280 machine was studied. The microstructural evolution with varying boron addition was examined using an optical microscope (OM), field emission scanning electron microscope (FESEM), and electron backscatter diffraction (EBSD). The added boron (0.1–1.5 wt%) reacted completely with Ti to form needle-like nano/micro TiB particles and induced grain refinement in the microstructure. The L-PBF fabricated TiB/Ti-6Al-4V composites with 0.5 wt% B and above altered the microstructure drastically from martensitic lath to equiaxed α. The microhardness and wear properties of the nanocomposite improved significantly with the increased concentration of boron. Nearly four-fold improvement in wear performance was associated with grain refinement and the formation of nano-sized TiB precipitates.

Effects of boron on microstructure and properties of microwave sintered FeCoNi1.5CuY0.2 high-entropy alloy

The mechanical properties of high-entropy alloys (HEAs) containing rare earth are improved by adding boron element. Under the condition that the content of rare-earth is fixed, FeCoNi1.5CuY0.2Bx high-entropy alloy with different boron atom ratios (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) is prepared by advanced microwave sintering process. The effect of boron addition with different atomic ratios on the phase evolution, microstructure, compressive mechanical properties and magnetic properties of the FeCoNi1.5CuY0.2 high-entropy alloy is emphatically studied. The results show that the phase transformation temperature decreases with the increase of boron content, which is conducive to the rapid sintering at low temperature. When boron content is less than 0.4 atomic ratio, the alloy is dominated by FCC base phase and BYO3, eliminating the oxidation phase of Y2O3. When boron adding amount as x = 0.4, it has the largest maximum compression ratio. When the amount of boron exceeds 0.4 atomic ratio, boride precipitates in the alloy, which increases the strength and hardness and at the cost of plasticity and soft magnetism. When the amount of boron is x = 1, the hardness arrives at utmost, and the compressive strength, yield strength and hardness are 1546 MPa, 1112 MPa and 367.1HV, respectively, which are 150%, 129% and 29.03% higher than those of boron-free sample. The improvement of mechanical properties is due to the fact that boron with small atomic size is easy to solute into the FCC base phase, forming interstitial solid solution, which results in lattice distortion and solid solution strengthening effect. And BY12 particles precipitated in BYO3 have dispersion strengthening effect on the alloy.

Effect of Boron on the Microstructure Evolution and Dynamic Recrystallization Kinetics of ALLVAC718Plus Superalloy

In this study, the effect of boron addition on the hot compression behavior and dynamic recrystallization kinetics of 718Plus nickel-based superalloy were investigated by isothermal compression tests at the deformation temperature range of 900-1050 °C and strain rate range of 0.01-1 s−1. Optical and field emission scanning electron microscopy techniques were employed to investigate the microstructural evolutions. The results indicated that the addition of boron reduces the flow stress of 718Plus superalloy. This could be attributed to the decrease in the volume fraction of Ni3(Al, Ti) particles. Microstructural observations revealed more volume fraction of dynamic recrystallization in the boron-bearing alloy at low-deformation temperatures, i.e., 900 and 950 °C. In contrast, at high temperatures of 1000-1050 °C, recrystallization is retarded mainly due to the segregation of boron to the grain boundaries.

The Effect of Boron Addition on The Microstructure and Corrosion Resistance of Cu-Al-Ni Shape-Memory Alloys Prepared by Powder Technology

Due to their promising mechanical characteristics, copper-based shape-memory alloys (SMAs) are crucial for numerous applications. This research inspects the outcomes of various quantities (0.4%, 0.8% and 1.2% wt) of boron (B) additions on the resistance against corrosion and the microstructure of Cu-Al-Ni SMAs using SEM, EDS, XRD and electrochemical tests in a solution of 3.5% NaCl. Numerous measurement baths were used for aged / unaged Cu-Al-Ni-xB SMAs. The electrochemical tests were performed over several periods to confirm the reliability of the corrosion-resistance property, after which the samples were verified using solutions of 3.5% NaCl. The experimental results demonstrated that adding 1.2% wt B followed by an ageing process resulted in an improvement in the corrosion resistance in Cu-Al-Ni SMAs and a decrease in the corrosion rate by 58%.

Effect of Boron Addition for on Time Temperature Transformation Behavior in Si Added High Carbon Steels

Effect of Boron Addition for on Time Temperature Transformation Behavior in Si Added High Carbon Steels

Effect of Boron Addition on Testicular Development of Ostrich

Effect of boron on development of testis in the ostrich was studied by observing the changes in the microstructure and ultrastructure. Apoptotic status of testicular cells and hormone level were examined. Compared with the control group, the experimental groups exhibited different degrees of change in the histological structure of the testis on addition of boron in different quantities. Cell apoptosis could be detected in testicular tissues of both control and experimental groups, mainly in Leydig cells and spermatocytes. Level of the follicle stimulating hormone (FSH), estradiol (E2), luteinizing hormone (LH) and testosterone (T) of the serum in the experimental groups also varied compared with those in the control group. In the present study, 100 mg/l of boron when supplemented with drinking water was helpful for the development of testis in the ostrich. It was also observed that high doses of boron significantly inhibited cell development in the testis of the ostrich.

Investigation of the welding joints properties made by electrodes with coating comprising a boron compound

ABSTRACT The authors studied the effect of boron additives in the coating of electrodes. It is shown that the additions of boron promotes the formation of new solid, highly disperse and structured phases in the seam which, under certain conditions of their formation and isolation, influence the structure of the steel, carry out dispersed or zone hardening, and inhibit the development of cold cracks. The performed work makes it possible to quantitatively and qualitatively characterize the effect of boron on the structure of the welded seam, to expand the field of application of electrodes with a coating comprising boron.

Effects of Boron Addition on the Structure and Properties of Cr–Al–Ti–N Coatings Obtained Using the CFUBMS System

The influence of boron on the structure and on the mechanical and tribological properties of protective coatings of the Cr–Al–Ti–N alloys obtained by magnetron sputtering in a closed unbalanced magnetic field using segmented planar ceramic SHS targets has been studied. The obtained coatings were examined using glow discharge optical emission spectroscopy, scanning electronic microscopy, X-ray diffraction phase analysis, nanoindentation, and tribological tests according to the pin-on-disk scheme. It has been shown that the introduction of B results in the suppression of the columnar structure and the reduction of the roughness of the coatings. Hardness, elasticity modulus, elastic recovery, wear resistance, and the coefficient of friction of coatings of the Cr–Al–Ti–B–N alloys have been determined. The introduction of 2.3 at % B leads to a high hardness (H = 15 GPa), stable friction coefficient (f = 0.65), and a decrease of the reduced wear (Vw = 7.5 × 10–6 mm3/(N m)). It has been shown that the hard Cr–Al–Ti–B–N coatings of the optimal composition in their mechanical and tribological properties exceed the coatings without boron addition.

Effect of boron addition on the microstructure and mechanical properties of K4750 nickel-based superalloy

The effect of boron addition at 0, 0.007 wt. % and 0.010 wt. % on the microstructure and mechanical properties of K4750 nickel-based superalloy was studied. The microstructure of the as-cast and heat-treated alloys was analyzed by SEM, EPMA, SIMS and TEM. Lamellar M5B3-type borides were observed in boron-containing as-cast alloys. After the full heat treatment, boron atoms released from the decomposition of M5B3 borides were segregated at grain boundaries, which inhibited the growth and agglomeration of M23C6 carbides. Therefore, the M23C6 carbides along grain boundaries were granular in boron-containing alloys, while those were continuous in boron-free alloys. The mechanical property analysis indicated that the addition of boron significantly improved the tensile ductility at room temperature and stress rupture properties at 750 ℃/430 MPa of K4750 alloy. The low tensile ductility at room temperature of 0B alloy was attributed to continuous M23C6 carbides leaded to stress concentration, which provided a favorable location for crack nucleation and propagation. The improvement of the stress rupture properties of boron-containing alloys was the result of the combination of boron segregation increased the cohesion of grain boundaries and granular M23C6 carbides suppressed the link-up and extension of micro-cracks.

Microstructure and hot ductility behavior of Ni-based superalloy U720Li with boron addition

High-alloyed superalloy U720Li is difficult to be processed through the conventional cast and wrought route. Boron is an important strengthening element for superalloys, but the role of boron in the hot ductility of U720Li alloy is not clear. This study is focused on the effect of boron addition, in the range of < 0.0005 wt%–0.0240 wt%, on the microstructure and hot ductility behavior of superalloy U720Li. It is found that boron addition significantly increases the content of eutectic (γ + γ′) and greatly affects the degree of continuity of the grain boundary eutectic (γ + γ′) precipitation. Boron addition dramatically worsens the 1100 °C tensile ductility of conventional cast U720Li alloy and causes a change in tensile fracture mode from transgranular to intergranular. The eutectic (γ + γ′) represents the most effective site for crack initiation. Boron deteriorates the hot ductility mainly by promoting the continuous precipitation of eutectic (γ + γ′) along the grain boundary.

Effect of boron addition on the phase-transition temperature of CoPt-B nanoparticles synthesized by sol–gel autocombustion using sago starch as a chelating agent

In this research, we reported the effect of boron addition on the phase-transition temperature of CoPt-B nanoparticles using a sol–gel autocombustion method. Sago starch was used as a chelating agent. From the results, the suitable values of the sago starch concentration, boron concentration, and annealing temperature were determined to be 10% (w/v), 0.20 mol/L, and 500 °C, respectively. All the synthesized samples were characterized by the SEM, TEM, EDS, XRD, and VSM techniques. The XRD patterns of the synthesized CoPt-B nanoparticles demonstrated that the phase-transition temperature of CoPt-B changes from the disordered A1 phase to the ordered L10 phase at 500 °C. It can be concluded that the addition of boron could reduce about 100 °C of the ordering temperature of CoPt-B. Moreover, the VSM data confirmed that the obtained samples exhibited their ferromagnetism properties, indicating that the synthesized CoPt-B nanoparticles can be applied as ultrahigh-density magnetic recording media.