Carbon Polyethylene Research Articles

Preparation of chlorinated polyethylene carbon black benzoxazine composites and with Positive Temperature Coefficient properties

Chlorinated polyethylene (CPE)/carbon black (CB)/ benzoxazine composites with positive temperature coefficient (PTC) characteristics are prepared using the conventional melt-mixing method. The research investigates how benzoxazine content and curing time impact the PTC/NTC characteristics, resistivity, microstructure, and crystallization behavior of these composites.The findings demonstrated a positive correlation between the room temperature resistivity of CPE/CB/benzoxazine composites and benzoxazine content, making the control of benzoxazine content particularly important. Scanning electron microscopy (SEM) reveals that these composites maintain a porous isolated structure regardless of curing time. However, crystallinity decreases as curing time increases. Optimal conditions are achieved with benzoxazine concentration of 2wt% and a curing time of 45minutes, resulting in a PTC intensity peak exceeding 5 after R-T cycling. Additionally, at 2wt% benzoxazine content and a curing time of 60minutes, a three-dimensional cross-linked network is formed. This network confines carbon black within specific regions, preventing large-scale aggregation and eliminating the NTC effect. After three thermal cycles, the PTC intensity stabilizes around 3.8, indicating good cycling stability.

Potent anti-inflammatory and anti-apoptotic activities of electrostatically complexed C-peptide nanospheres ameliorate diabetic nephropathy

In the present era of “Diabetic Pandemic”, peptide-based therapies have generated immense interest however, are facing odds due to inevitable limitations like stability, delivery complications and off-target effects. One such promising molecule is C-peptide (CPep, 31 amino acid polypeptide with t1/2 30 min); it is a cleaved subunit of pro-insulin, well known to suppress microvascular complications in kidney but has not been able to undergo translation to the clinic till date. Herein, a polymeric CPep nano-complexes (NPX) was prepared by leveraging electrostatic interaction between in-house synthesized cationic, polyethylene carbonate (PEC) based copolymer (Mol. wt. 44,767 Da) and negatively charged CPep (Mol. wt. 3299 Da) at pH 7.4 and further evaluated in vitro and in vivo. NPX exhibited a spherical morphology with a particle size of 167 nm and zeta potential equivalent to +10.3, with 85.70 % of CPep complexation efficiency. The cellular uptake of FITC-tagged CPep NPX was 95.61 % in normal rat kidney cells, NRK-52E. Additionally, the hemocompatible NPX showed prominent cell-proliferative, anti-oxidative (1.8 folds increased GSH; 2.8 folds reduced nitrite concentration) and anti-inflammatory activity in metabolic stress induced NRK-52E cells as well. The observation was further confirmed by upregulation of anti-apoptotic protein BCl2 by 3.5 folds, and proliferative markers (β1-integrin and EGFR) by 3.5 and 2.3 folds, respectively, compared to the high glucose treated control group. Pharmacokinetic study of NPX in Wistar rats revealed a 6.34 folds greater half-life than free CPep. In in-vivo efficacy study in STZ-induced diabetic nephropathy animal model, NPX reduced blood glucose levels and IL-6 levels significantly by 1.3 and 2.5 folds, respectively, as compared to the disease control group. The above findings suggested that NPX has tremendous potential to impart sustained release of CPep, resulting in enhanced efficacy to treat diabetes-induced nephropathy and significantly improved renal pathology.

Direct synthesis of highly crumpled nitrogen-rich porous carbon nanosheets with a mesopore-dominant for high performance supercapacitors

Direct synthesis of porous carbon nanosheets without adding any chemical activators or templates remains a great challenge. In this work, we present a novel and simple method to synthesize highly crumpled nitrogen-rich porous carbon nanosheets (HCNPCNS) by one-step procedure based on the direct carbonization of polyethylene and melamine. HCNPCNS consist of interconnected crumpled porous carbon nanosheets with a nanoscale thickness, an ultrahigh nitrogen content (10.3 at.%) and a mesopore-dominant, which thus ensure much more available surface area. As a result, the unique structures of HCNPCNS exhibit a high specific capacitance of 257.2 F g−1 in 6 M KOH and 265 F g−1 in 1 M H2SO4, high rate capability both in 6 M KOH and 1 M H2SO4, and long cycling stability of 96.7 % in 6 M KOH and 100 % in 1 M H2SO4 when act as supercapacitor electrodes. Moreover, the HCNPCNS//HCNPCNS based supercapacitor in ionic liquid can deliver an excellent power density of 175 kW kg−1 and an energy density of 58.8 W h kg−1. This strategy opens up a new avenue towards preparing porous carbon nanosheets without complicated procedure and particular chemical activators or templates for high performance supercapacitors.

Influence of ethylene oxide monomeric units on the bonding of poly(ethylene carbonate) (PEC) onto nickel‑manganese‑cobalt oxides

Polymers are very attractive materials in the field of all solid-state batteries not only because they act as binders, and even electrolytes if properly doped by salts, in electrodes but also because they can bring their unique ease of processing in large scale production by technologies such as extrusion. The issue of their adhesion, or at least wetting, onto materials such as metal oxides, is nevertheless of major importance since it plays a major role in charge transfer through interfaces. The present study shows the importance of the composition of polyethylene carbonate (PEC) that can be used as binder and solid electrolyte basis, on its bonding to NMC of the 622 type (LiNi0.6Mn0.2Co0.2O2) frequently used as insertion material in positive electrodes. Indeed, dynamic mechanical spectroscopy in the vicinity of the glass transition of the polymers reveals a significant bonding for one over three different PEC used in this study. The bonding was also clearly visible on images obtained by scanning electron microscopy and indirectly confirmed by rheological measurements. A deep analysis of the structure of the polymers by 1H NMR shows a significant difference in the content of ethylene oxide units. This difference was thought to be at the origin of the bonding.

Solid-State NMR Revealing the Impact of Polymer Additives on Li-Ion Motions in Plastic-Crystalline Succinonitrile Electrolytes

To enhance the safety of lithium-ion batteries (LIBs), alternatives to liquid electrolytes are widely studied. One of them is the plastic-crystal succinonitrile (SN) which can solvate various Li salts.[1] This system can be further extended by inserting polymers, bringing additional advantages such as higher melting points and the possibility of adjusting thermo-mechanical and electrochemical properties.[2]The plastic-crystalline electrolyte consisting of the Li salt lithium bis(trifluoro-methanesulfonyl)imide (LiTFSI) dissolved in SN was extended by adding various thermoplastic polymers, namely, polyacrylonitrile (PAN), poly(ethylene oxide) (PEO), polyethylene carbonate (PEC), and polyvinylpyrrolidone (PVP). Even small amounts (10 wt %) of added polymer to the SN-base were found to impact the Li-ion mobility. Variable temperature investigations on structure and ion dynamics were performed using static and magic angle spinning (MAS) solid-state NMR and various relaxometry measurements. Influence of the Li-concentration and the polymers’ functional groups on the structure of SN and the resulting Li-ion mobility was elaborated. Activation energies and jump rates of the Li-ions were determined.As a result, the PAN containing system stands out to be a promising candidate for application in future LIBs as it shows high ion mobility, low activation energy, and a high potential for further modifications. Solid-state NMR turned out to be a reliable method and a good alternative to impedance spectroscopy measurements for investigating ion mobility behaviour providing even more information.[3]Literature:[1] S. Long, D. R. MacFarlane, M. Forsyth, Solid State Ionics 2004, 175, 733.[2] N. Voigt, L. van Wüllen, Solid State Ionics 2014, 260, 65.[3] J. Möller, V. van Laack, K. Koschek, P. Bottke, M. Wark, J. Phys. Chem. C 2023, 127, 1464.

Solid-State NMR Revealing the Impact of Polymer Additives on Li-Ion Motions in Plastic-Crystalline Succinonitrile Electrolytes

To enhance the safety of lithium-ion batteries (LIBs), alternatives to liquid electrolytes are widely studied. One of them is the plastic-crystal succinonitrile (SN) which is able to solvate various Li salts. This system can be further extended by inserting polymers, bringing additional advantages such as higher melting points and the possibility of adjusting thermo-mechanical and electrochemical properties. The plastic-crystalline electrolyte consisting of the Li salt lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) dissolved in SN was extended by adding various thermoplastic polymers, namely, polyacrylonitrile (PAN), poly(ethylene oxide) (PEO), polyethylene carbonate (PEC), and polyvinylpyrrolidone (PVP). Even small amounts (10 wt %) of added polymer to the SN-base were found to impact the Li-ion mobility. Variable temperature investigations on structure and ion dynamics were performed using static and magic angle spinning (MAS) solid-state NMR and various relaxometry measurements. Influence of the Li concentration and the polymers’ functional groups on the structure of SN and the resulting Li-ion mobility was elaborated. Activation energies and jump rates of the Li ions were determined. As a result, the PAN-containing system stands out to be a promising candidate for application in future LIBs as it shows high ion mobility, low activation energy, and a high potential for further modifications. Solid-state NMR turned out to be a reliable method and a good alternative to impedance spectroscopy measurements for investigating ion mobility behavior providing even more information.

Polyethylene (PE) reduction method towards V2O3@C-PE as cathode of zinc ion batteries with high stability and capacity

Vanadium-based aqueous zinc ion batteries materials have high theoretical specific capacity and have advantages in energy storage. But poor conductivity, stability and high manufacturing cost are not conducive to its development. In this work, we prepare V 2 O 3 @C-PE by reducing ammonium metavanadate (NH 4 VO 3 ) with low-cost polyethylene (PE). PE creates a large amount of hole structure for the V 2 O 3 @C-PE sample, and the V 2 O 3 agglomeration is inhibited by the combination of reduced V 2 O 3 and PE carbon. In ZnSO 4 electrolyte system, the specific capacity of V 2 O 3 @C-PE electrode reaches 393 mA h g −1 at the current density of 0.1 A g −1 , and the capacity retention and specific capacity are 97.3 % and 223 mA h g −1 after 1600 cycles at 20 A g −1 . In addition, through the study of zinc storage mechanism, the V 2 O 3 @C-PE electrode is oxidized to V 5 O 12 ·6H 2 O when first charged and then stores zinc in this form. Due to the excellent electrochemical performance and low manufacturing cost of V 2 O 3 @C-PE electrode, we consider it potentially competitive in the field of energy storage.

Shear enhancement of mechanical and microstructural properties of synthetic graphite and ultra‐high molecular weight polyethylene carbon composites

AbstractUltra‐high molecular weight polyethylene (UHMWPE) has a variety of industrial and clinical applications due to its superb mechanical properties including ductility, tensile strength, and work‐to‐failure. The versatility of UHMWPE is hindered by the difficulty in processing the polymer into a well consolidated material. This study presents on the effects of shear imparted by equal channel angular pressing (ECAP) on UHMWPE composites containing Nano27 Synthetic Graphite (N27SG). Ductility and work‐to‐failure improvements up to ~60–80% are obtained in sheared N27SG‐UHMWPE composites as compared to non‐sheared N27SG‐UHMWPE controls of the same composition. Microscopy reveals increased fusion at particle boundaries and smaller voids in the sheared materials. Micro‐computed tomography results indicate different distribution of N27SG particulates in ECAP samples as compared to CM indicating enhanced grain boundary interactions. Tradeoffs are not avoided as ECAP samples were lower in conductivity as compared to compression molded (CM) billets of the same weight percent. However, ECAP samples were able to be doped with more N27SG allowing for an ~170% increase in conductivity over CM samples of the same work‐to‐failure. This work shows that ECAP is a viable processing method for obtaining stronger, more ductile conductive composite materials.

Upcycling Waste Polyethylene into Carbon Nanomaterial via a Carbon-Grown-on-Carbon Strategy.

Upcycling waste plastics (e.g., polyethylene (PE)) into value-added carbon products is regarded as a promising approach to address the increasingly serious waste plastic pollution and simultaneously achieve carbon neutrality. However, developing new carbonization technology routes to promote the oxidation of PE at low temperature and construct the stable cross-linking network remains challenging. Here, a facile carbon-grown-on-carbon strategy is proposed using carbon black (CB) to convert waste PE into core/shell carbon nanoparticles (CN) in high yields at low temperature. The yield of CN remarkably increases when the heating temperature decreases or the dosage of CB increases. The obtained CN displays turbostratic structure and closely aggregated granular morphology with a size of ≈80nm. It is found that, prior to the oxidation and carbonization of PE, CB forms a 3D network architecture in the PE matrix. More importantly, CB not only catalyzes the partial oxidation of PE to form PE macromolecular radicals and introduce oxygen-containing groups at low temperature in the early stage, but also favors for the construction of a stable cross-linking network in the latter stage. This work offers a facile sustainable strategy for chemical upcycling of PE into value-added carbon products without post-treatments or usage of metallic catalysts.

Polycarbonate-Based Lithium Salt-Containing Electrolytes: New Insights into Thermal Stability

For investigation of the thermal stability of polycarbonate-based lithium salt-containing electrolytes, polycarbonate–salt mixtures [polyethylene carbonate (PEC) and polypropylene carbonate (PPC) w...

Computational insight into the structural properties and redox chemistry of poly (ethylene carbonate) as electrolytes for Lithium batteries

New electrolytes with high electrochemical stability and ionic conductivity are important in the development of lithium ion batteries. Polyethylene carbonate (PEC) is a very promising candidate. Herein, the DFT modeling approach is performed to investigate the coordination structure of Li+ ion in PEC, and the redox potentials of a set of polymer models to assess the effect of polymer monomer unit composition. [Li(PEC)] [Anion] (BF4−, PF6−, ClO4−, TFSI−) are also considered. It is highlighted that the coordination shell of Li+ ion is most likely fully occupied by four carbonyl oxygen atoms of PEC. Next, the carbonate group can lead to greater oxidation stability than ester, ketone and ether group, the length and configuration of alkyl chain affect the redox potential only slightly. Furthermore, the addition of electron-withdrawing groups (-F and -CF3) can increase the oxidation stability of PEC, while the -CN group substitution shows the opposite effect, due to the ring formation or bond breaking of intramolecular structure. All these findings provide important information for understanding the ion-polymer interactions and synthesizing the promising new electrolyte molecules for high-voltage batteries.

Size-controlled, single-crystal CuO nanosheets and the resulting polyethylene–carbon nanotube nanocomposite as antimicrobial materials

In this study, size-controlled single-crystal copper oxide nanosheets (CuO NSs) were fabricated by a microwave-assisted chemical method. Next, their nanocomposites with high-density polyethylene (HDPE) were fabricated. These nanocomposites were further reinforced with carbon nanotubes (CNTs) of oil fly ash. The produced CuO NSs along with their polymer nanocomposites were evaluated as antimicrobial agents against Escherichia coli, Bacillus subtilis, and yeast Saccharomyces cerevisiae. Significant microbial-growth inhibition was observed. This inhibition correlated with oxygen defects, free Cu2+ ion release, and a change in the lattice constant c. These factors were found to increase with the increased molar ratio of the precursors and might be responsible for formation of additional reactive oxygen species. Moreover, adding 1 wt% of CuO NSs and 0.5 wt% of CNTs enhanced the mechanical properties of HDPE by ~ 20%. These results indicate that it is possible to design polymer nanocomposites that have both antimicrobial and enhanced mechanical properties for various applications, mainly in the healthcare sector.

Получение композиционных материалов на основе полиэтилена методом полимеризации in situ на титан-магниевом катализаторе, закрепленном на поверхности углеродных нанотрубок различного типа

The data on the preparation of composite materials containing polyethylene and multi-walled carbon nanotubes (MWCNTs) of the Taunit brand are presented. To obtain these composites by in situ polymerization, a catalytic system formed by the interaction of an organomagnesium compound and TiCl4 on the surface of nanotubes was used. The catalyst fixed on the MWCNT surface has a high activity in ethylene polymerization and allows to obtain a polymer with different molecular weight. The data on the formation of a polymer on the MWCNT surface and the morphology of composites formed on various Taunit samples are presented.

Experimental and numerical approach to study mechanical and fracture properties of high-density polyethylene carbon nanotubes composite

This work investigates the elasto-plastic and fracture properties of high-density polyethylene (HDPE) carbon nanotubes (CNTs) composite using a multi-scale finite element (MSFE) approach. The composites consist of CNTs, which are randomly embedded within the HDPE matrix throughout the volume. CNT reinforcement is numerically modelled by considering elastic properties while the elasto-plastic constitutive law is used for the matrix (HDPE) composition. Elastic properties of composites are estimated at meso-scale by numerical modelling of a representative volume element (RVE). Hollomon’s (power-hardening law) model has been employed to get the plastic properties of the polymer composite. Equivalent consecutive properties are predicted at meso-scale, further, these properties have been used at macro-scale simulation for fracture analysis. A detailed study of stress intensity factors has been presented for the different volume fraction of CNTs in the composite composition. The presented numerical results are supported by experimental investigations.

Solid-to-liquid transition of polycarbonate solid electrolytes in Li-metal batteries

In this work, we analyzed the thermal stability of polycarbonate: lithium trifluoromethane sulphonylimide (LiTFSI) systems. Polyethylene carbonate (PEC) and polypropylene carbonate (PPC) undergo depolymerization to ethylene carbonate (EC) and propylene carbonate (PC), respectively, in the presence of Li salt under annealing treatment. The decomposition reaction can explain the surprising high ionic conductivity recently reported for solid polymer electrolyte (SPE) polycarbonate-based systems. Because this phenomenon can strongly impact the results of SPE research, it is essential to control the depolymerization of polymers to avoid inaccurate electrochemical performance. In addition, we observed that the standard drying procedure for the preparation of high-salt-concentration polymer (polymer-in-salt) SPEs traps a high amount of residual solvent, e.g., acetonitrile (ACN), due to the strong bond between the solvent and ionic species. This finding represents another factor influencing the remarkably high ionic conductivity.

New Insights into the Behavior of Polycarbonate-Based Lithium Salt Containing Electrolytes Regarding Thermal Long-Term and Electrochemical Stability

For lithium ion batteries solid-state electrolytes like polymers gained more and more attention in the last years, especially due to safety reasons. Polyethylene oxide (PEO) based systems are still state of the art. One of its major drawbacks is the highly crystalline structure, which inhibits fast migration of lithium ions and results in a low transference number and low conductivity [1]. Recently, polycarbonate based polymer electrolytes gained some interest [2,3]. Polycarbonates were assumed to show weaker ion-dipole interactions in contrast to PEO, given rise to higher transference numbers [2]. With suitable additives and high salt concentrations, higher ionic conductivities were reported at moderate temperatures (>60 °C) [3]. Nevertheless, there is still a lack of knowledge concerning long-term performance of the polycarbonate-salt-mixtures as electrolytes in terms of thermal stability in the temperature range of solid-state batteries. Therefore, we prepared lithium salt containing polycarbonate samples using either solution casting with additional removal of the solvent or the hot press method. We examined the behavior of polycarbonate salt mixtures over a period of time at given temperatures. Investigation methods such as differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (NMR) and electrochemical impedance spectroscopy (EIS) were used. The results of the experiments indicate that e. g. the mixture LiTFSI in polyethylene carbonate (PEC) suffers from a salt catalyzed decomposition for longer times whereas polypropylene carbonate (PPC) is stable. Furthermore, candidates with good thermal long-term stability (e. g. PPC/LiTFSI) were analyzed concerning their ionic conductivity and their electrochemical stability window. If necessary, improvements were made to increase the electrochemical stability (e. g. down to lithium stripping / plating) or the conductivity by use of different additives, e.g. plasticizers and SEI additives. Acknowledgements The authors acknowledge funding by Federal Ministry for Economic Affairs and Energy (BMWi) under the project FesKaBat (03ET6092E).

Analysis of Transport Properties of Polycarbonate-Based Polymer Electrolytes Containing Lithium (perfluoroalkylsulfonyl)Imides for Possible Application in Lithium-Ion Batteries

The search for safe electrolytes for the use in lithium metal batteries and high energy density batteries has driven the interest in alternative polymer electrolytes with enhanced performance. The central interest focuses on transport properties as good ionic conductivities and on high electrochemical stability towards lithium metal anodes and cathodes for high voltage batteries. To gain insight in the Li-ion movement in polycarbonates, as dry or gel electrolyte, is necessary for understanding how to improve these systems and achieve better performances. In this context, we present a critical study on polycarbonates as alternative to polyethylene oxide (PEO) in salt-in-polymer electrolytes. [1] Polymer electrolytes based on PEO as well as some related with grafted PEO side chains along polymer backbones such as polyphosphazenes, polysiloxanes and others are known to reach ionic conductivities in the range of 10-3 - 10-4 S·cm-1 in a favourable temperature range and typical Li+ transference numbers around 0.2.[2,3] In contrast to that, polycarbonates were reported to exhibit transference numbers up to about 0.5 as well as higher ionic conductivities and electrochemical stability.[4] In this work, the commercially available polycarbonates polyethylene carbonate (PEC) and polypropylene carbonate (PPC) were prepared as flexible self-standing membranes with dissolved fluorinated lithium salts such as LiTFSI and others. With the use of propylene carbonate (PC) novel gel-polymer electrolytes have been fabricated. The ion conducting polymer membranes were examined regarding their electrochemical and transport characteristics with respect to possible battery applications. We studied ionic conductivity and Li-ion transference number as well as the coordination of lithium with different dissolved lithium salts on carefully purified polycarbonate samples. We obtained ionic conductivities in dry state around 10-6 S·cm-1 at room temperature and up to 10-3 in gelled systems. The novel gel systems based on PEC and PPC perform significantly better than the dry alternatives. Acknowledgements The authors acknowledge the funding within the project BenchBatt (03XP0047A) by the German Ministry of education and research. We are also grateful for the support by the Helmholtz Association within the Helmholtz Institute Münster (HI MS). [1] P. Knauth, Solid State Ionics, 180 (2009) 911-916.[2] M. Grünebaum, M.M. Hiller et al., Prog. Solid State Chem. 42 (2014) 85–105.[3] M. Hiller, M. Joost et al., Electrochim. Acta 114 (2013) 21-29.[4] Y. Tominaga, K. Yamazaki, Chem. Commun. 50 (2014) 4448-4450.

Investigation of Atomic Layer Deposited Al2O3 High Energy Nickel Cobalt Manganese Oxide Cathode Materials

High-Energy Nickel Cobalt Manganese Oxide (HED-NCM) is a state-of-art positive electrode material which achieves a high specific capacity (~250 mAh/g). Overall cycling life is limited by electrode degradation, stemming mainly from oxygen release as well as transition metal dissolution. To mitigate the latter problem, a thin layer of aluminum oxide (Al2O­3­) can be applied to the active material by atomic layer deposition (ALD) to form an artificial cathode-electrolyte interphase (CEI). Testing has shown that the Al2O3 coating improves overall reversible capacity, most notably at high temperature (40oC). However, effect of the Al2O3 on the CEI and SEI formed upon cycling has yet to be understood. The cycling performance and surface chemistry Al2O3 coated HED-NCM materials cycled at room temperature and 40°C were investigated via ATR-FT-IR and XPS spectroscopies, and ICP-MS after the first and 50th cycles. Overall, electrodes made with Al2O3 coated material had lower concentrations of polyethylene carbonate and fluorine species, and Al2O­3­ coating helps in preventing transition metal dissolution.

Observations of a novel strengthening mechanism in HDPE nanocomposites

Previous strengthening mechanisms described in literature for high density polyethylene (HDPE) carbon nanotubes composites are typical of those observed in fibre reinforced polymeric micro composites. Here, we present a new molecular level strengthening mechanism based on HDPE carbon nanotubes composite, which has not been reported before to the best of authors’ knowledge. The HDPE nanocomposite was produced by melt intercalation technique via twin-screw extrusion. Thereafter, the samples were subjected to mechanical tensile tests and scanning electron microscope (SEM) examination. Carbon nanotubes (CNTs) were found to be disentangled from the polymer molecules after yielding and prior to breaking. SEM and optical microscopic observations revealed visible black agglomerate bands at 45° appeared after yielding and prior to the breaking of the ductile HDPE. It was observed that CNTs were pushed out from the intricate mechanical interlocking with the thermoplastic polymeric chains of HDPE during strain hardening.

Friction stir welding of high density polyethylene—Carbon black composite

This investigation elucidates the important role of process temperatures in the friction stir welding of polymers. Measurements of the material temperatures were performed by means of an infrared camera and embedded thermocouples under the weld line. An inverse heat conduction method was also utilized to determine the temperature distribution in the workpiece numerically. The weld quality was determined in terms of the amount of defects present in the stir zone and the tensile strength of the joint. It was found that considerable melting occurred under the rotating shoulder and on the trailing side of the rotating pin. Movement of the molten material by the rotating tool created macro- and micro-voids in the stir zone. Crystallinity and nano-hardness measurements indicated that crystallinity was higher under the tool shoulder due to exposure to high temperatures. Tensile strength of the joint was mainly attributed to fusion welding on the top region and hot forging at the root. Decreasing the welding speed and increasing the penetration depth helped improve the weld quality.