{"title":"Improvements in manufacturability, bonding strength, and curing efficiency of a silicone adhesive","authors":"","doi":"10.1016/j.jajp.2024.100243","DOIUrl":"10.1016/j.jajp.2024.100243","url":null,"abstract":"<div><p>Two-component room temperature vulcanizing silicone adhesive RTV566 with a lower elastic modulus has been widely used in precision optomechanical products such as remote sensors and aerospace infrared cameras. However, the silicone adhesive is of poor manufacturability due to its extremely high viscosity, and the bonded joint usually exhibits low bonding strength and requires a long curing time. This paper investigates a way to improve both the adhesion strength and curing efficiency of Invar alloy and optical glass with RTV566 through single-lap experiments. It is found that adding small amounts of acetone and water can significantly reduce the viscosity, enhance the bonding strength, and shorten the curing time. The viscosity can be reduced by 63.4 % and the bonding strength can be improved by 136.4 % with the weight ratio of adhesive to acetone being 20:2. Moreover, a little amount of water in the weight ratio of 100:10:0.1 (adhesive: acetone: water) can shorten the curing time from 7 days to 4 days without harms to the bonding strength and elastic modulus. As to the mechanism, the silicone adhesive can be dissolved by acetone and its sulfuration reaction can be enhanced by water, resulting in good manufacturability and high curing efficiency. This work contributes a novel and easy-to-use method to greatly improve the performances of the bonding process of precision optical structures.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000591/pdfft?md5=7609b8d2d67a410ce4dc74ffce696493&pid=1-s2.0-S2666330924000591-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fracture toughness and microstructural analysis of rotary friction welded S355J2 and SS316L steels for critical applications","authors":"","doi":"10.1016/j.jajp.2024.100244","DOIUrl":"10.1016/j.jajp.2024.100244","url":null,"abstract":"<div><p>Dissimilar metal welding is seeing growing adoption across industries to enhance structural functionality and efficiency. Achieving high-quality, defect-free dissimilar weld joints requires a comprehensive understanding of the interrelationships between the welding-induced microstructural changes and the material's performance characteristics, particularly its fracture-related properties. This study investigates the impact of microstructural changes on the fracture toughness of dissimilar welds between structural low-carbon steel (S355J2) and austenitic stainless steel (SS316L) prepared using the Rotary Friction Welding (RFW) technique. Welding preforms were created from respective pipe pup pieces. The evaluation involves microstructural analysis, tensile testing, hardness testing, and fracture toughness testing using compact tension specimens derived from various zones of the weld joints. Results revealed significant microstructural differences across the weld joint. The weld region exhibited stable hardness with a maximum of 208 HV1 in S355J2′s thermo-mechanically affected zone (TMAZ). High tensile strength (Ultimate Tensile Strength 540 MPa, Yield Strength 367 MPa) with failures mainly on the S355J2 side. The fracture toughness (K<sub>Q</sub>) matched parent metal values, with the RFW weld centre line (WCL) showing superior crack tip opening displacement (CTOD) of 0.35 mm. Fractography generally indicates ductile failure.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000608/pdfft?md5=1dc49706d6daaaa8ad10f8ccf1c90f42&pid=1-s2.0-S2666330924000608-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of weld-line position on springback behavior in advanced high-strength steel tailor-welded blanks on hat-shaped bending application","authors":"","doi":"10.1016/j.jajp.2024.100241","DOIUrl":"10.1016/j.jajp.2024.100241","url":null,"abstract":"<div><p>In this study, both experiments and finite-element analysis are performed to elucidate the effect of weld-line position on the springback behavior of advanced high-strength steel tailor-welded blanks (AHSS-TWBs). AHSS-TWBs are fabricated from grade 590Y high-strength steel and 980Y advanced high-strength steel, each with a thickness of 1.2 mm. Gas tungsten arc welding is performed to obtain autogenous butt-weld joints. Three distinct weld-line position patterns are systematically analyzed to investigate the springback phenomenon via hat-shaped draw bending. Experiments on the AHSS-TWBs show that the weld-line position affects springback. The stress distribution changes with the weld-line position, thereby initiating variations in both the components of the bending moment and the corresponding springback angle. Depending on the weld-line position, different springback behaviors and bending moments are resulted on the components.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000578/pdfft?md5=428b51fc4d13681df3ff6261a668485b&pid=1-s2.0-S2666330924000578-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142020743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of foam interlayer thickness and pore size on the microstructure and properties of brazed joints","authors":"","doi":"10.1016/j.jajp.2024.100242","DOIUrl":"10.1016/j.jajp.2024.100242","url":null,"abstract":"<div><p>Ni foam was introduced as an interlayer to improve the performance of the brazed C/C composite-TC4 titanium alloy joint, and high-quality brazed connections of c/c composites and TC4 were realized. Compared to a brazing joint without foam, the introduction of a foam Ni interlayer can achieve a more uniform bonding interface. The effects of the thickness and pore size of the foam Ni interlayer on the microstructure, mechanical properties and residual stresses of the joints were investigated. With increasing thickness and pore diameter, Ag-based solid solutions and Ti–Cu intermetallic compounds first become more dispersed and smaller at the center of the brazed joints, and then aggregate to become larger. The brazed interface microstructure with a 0.4 mm thick foam Ni interlayer with a pore size of 0.5 mm was more uniform, and the shear strength of the joint reached 21.23 MPa, representing an 85.96 % increase compared to the joint without the foam Ni interlayer. The residual stress and its distribution calculated by finite element method (FEM), and the residual stress of the brazed joint decreased from 467 MPa/-289.53 MPa to 457.96 MPa/-234.98 MPa. These results indicated that the Ni foam could act as a buffer layer to reduce the residual thermal stress, and improve the mechanical properties of C/C composite-TC4 titanium alloy joint.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266633092400058X/pdfft?md5=d396e81f9ecdb9fd147835189740a0c4&pid=1-s2.0-S266633092400058X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142011174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of welding current on the mechanical properties of Al 5083 alloy processed using high-current gas metal arc welding","authors":"","doi":"10.1016/j.jajp.2024.100240","DOIUrl":"10.1016/j.jajp.2024.100240","url":null,"abstract":"<div><p>This study investigated the effect of welding current during gas metal arc welding (GMAW) on the microstructure and composition of an Al 5083 alloy. As the welding current increased from 650 to 950 A, several changes were observed in the heat-affected zone (HAZ): grain coarsening and the formation of liquation cracks, and in the weld zone (WZ): increasing average secondary arm spacing and Mg loss. Therefore, the welding currents above 800 A are likely to cause liquation cracks in the HAZ and deterioration of the alloy's mechanical properties. Thus, welding condition with low heat input must be applied to improve the mechanical properties of the welds. This study provides a correlation between the weldability of Al 5083 alloy and welding current, offering a competitive advantage of liquid hydrogen storage containers.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000566/pdfft?md5=cbb7eec009a68bb35d90f8a5e128eea2&pid=1-s2.0-S2666330924000566-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141952557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flux enhancement with titanium or vanadium oxides addition for superior submerged arc welding of HSLA steel plates","authors":"","doi":"10.1016/j.jajp.2024.100238","DOIUrl":"10.1016/j.jajp.2024.100238","url":null,"abstract":"<div><p>A high-strength low-alloy (HSLA) steel plate of 10 mm thickness underwent submerged arc welding with enhanced fluxes containing additional titanium oxide (TiO<sub>2</sub>) or vanadium oxide (V<sub>2</sub>O<sub>5</sub>). The addition of TiO<sub>2</sub> led to the development of a finer acicular ferrite structure but coarsening the carbide and martensite/austenite (M/A) constituents, which marginally improved the hardness, tensile strength, and ductility of weld metal. Conversely, incorporating V<sub>2</sub>O<sub>5</sub> facilitated a substantial vanadium absorption (0.7 wt. %) in the weld metal, giving rise to a distinctive acicular microstructure less reliant on ferrite nucleation at non-metallic inclusions than conventional acicular ferrite. The distinctive microstructure, unique to vanadium steels, combined lath bainite with irregularly shaped granular bainite. The resultant dual-mode bainitic structure, coupled with a more uniform distribution of refined microphase constituents, outperformed the conventional acicular ferrite, delivering more than 20% and 13% improvements in yield and tensile strengths respectively, as evidenced by transverse tensile tests on the weld metals.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000542/pdfft?md5=72b4df01a39d4eb29881c56a83a0f7e1&pid=1-s2.0-S2666330924000542-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141841178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of laminate stacking sequence on the strength properties of aluminum alloy–carbon fiber-reinforced plastic dissimilar single-lap adhesive joints","authors":"","doi":"10.1016/j.jajp.2024.100239","DOIUrl":"10.1016/j.jajp.2024.100239","url":null,"abstract":"<div><p>Here, two single-lap adhesive joints (SLJs) of dissimilar materials were subjected to static and cyclic loading tests. A2017 aluminum alloy was used as an adherend for one, and carbon fiber reinforced plastic (CFRP) was used as the adherend for the other. Four types of orthogonal laminated CFRPs with different laminate stacking sequences were used as adherends to investigate the effect of adherend stiffness on the strength properties of the joints. Furthermore, the results of the finite element analysis of the dissimilar SLJs revealed that when the tensile load was applied to them, the out-of-plane deformation asymmetry increased with increasing difference in stiffness between both adherends. This asymmetry affected the peel and shear stress distributions. Furthermore, the experiments revealed that the static tensile strength of the SLJs increased with increasing stiffness of the CFRP adherend. Additionally, fracture simulation using cohesive-zone modeling (CZM) revealed that the SLJs with higher CFRP stiffness exhibited higher strength, qualitatively agreeing with the experimental results. CZM analysis and adhesion strain measurements during the tests indicated that failure occurred at the A2017 adherend–adhesive interface. In contrast, no differences were observed between the fatigue strengths of the different types of adherends in the short-life region, with a number of cycles to failure (N<sub>f</sub>) being ≤ 2 × 10<sup>5</sup>. However, in the long-life region, beyond N<sub>f</sub> = 2 × 10<sup>5</sup>, the SLJ bearing the unidirectional CFRP adherend exhibited lower fatigue strength than the others. The anodizing process on A2017 was found to improve fatigue strength by a factor of two or more.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000554/pdfft?md5=fc35686a8b4ac80f50530c5b1ef9a771&pid=1-s2.0-S2666330924000554-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mehdi Khalasi Dezfuli , Ali Heidary Moghadam , Mehdi Ghobeiti Hasab , Rouholah Ashiri
{"title":"Disclosing connection links between microstructure and mechanical performance in pulsating current gas tungsten arc welding of Hastelloy B-2 superalloy","authors":"Mehdi Khalasi Dezfuli , Ali Heidary Moghadam , Mehdi Ghobeiti Hasab , Rouholah Ashiri","doi":"10.1016/j.jajp.2024.100237","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100237","url":null,"abstract":"<div><p>In this study, welding a Ni-Mo-based superalloy (Hastelloy B-2) was examined in order to characterize the microstructure and mechanical performance of joints along with assessing the effects of current intensity on the microstructure and mechanical responses of different weld zones. The gas tungsten arc welding (GTAW) process was used to weld the samples using ERNiCrMo-2 filler metal. The pulsed current GTAW process was used to weld the superalloy sheets of thickness of 1 mm with background current (I<sub>b</sub>) of 20 A and 40 A and peak current (I<sub>p</sub>) of 80 A and 60 A. Tensile and Vickers microhardness tests were conducted to evaluate the effect of pulsed current on mechanical properties of the welds along with chemistry and microstructure characterizations. Finally, the fracture surfaces after the tensile test were studied using SEM fractography analysis. The results indicated that increasing I<sub>b</sub> and decreasing I<sub>p</sub> led to low heat input and high cooling rate resulting in a high thermal gradient. This caused microstructure transition from the columnar dendrites to the coaxial ones in the weld zone; molten metal convection in the fusion zone led to fine grains in the weld zone during welding time. Moreover, a significant decrease in the amount of molybdenum carbides at the interdendritic regions of the weld metal was observed under these conditions. The tensile strength of the weld metal was higher than that of the base metal resulting in the fracture of all welds from the base metal. Additionally, the microhardness results indicated a significant increase for the weld metal compared to both heat-affected zone (HAZ) and base metal. The higher mechanical properties of the weld metal is attributed to the increase in background current and decrease in peak current leading to a fine grain microstructure. Fractography following the tensile test showed a completely ductile fracture.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000530/pdfft?md5=b8f5e1a7f4a5a0f82392aba7f95844d3&pid=1-s2.0-S2666330924000530-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141480959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyo-Nam Choi , Jeong-Won Choi , Heon Kang , Hidetoshi Fujii , Seung-Joon Lee
{"title":"Effect of stacking-fault energy on dynamic recrystallization, textural evolution, and strengthening mechanism of Fe−Mn based twinning-induced plasticity (TWIP) steels during friction-stir welding","authors":"Hyo-Nam Choi , Jeong-Won Choi , Heon Kang , Hidetoshi Fujii , Seung-Joon Lee","doi":"10.1016/j.jajp.2024.100236","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100236","url":null,"abstract":"<div><p>This study aims to elucidate the effect of stacking fault energy (SFE) on the microstructural evolution and related hardening mechanisms of Fe−18Mn−0.6C−(0 and 1.5)Al and Fe−30Mn−3Al−3Si (wt.%) twinning−induced plasticity (TWIP) steels during friction stir welding (FSW) using a high−resolution electron backscattered diffractometer. With increasing SFE, the intensities of the Goss, CuT, and Brass components increased via active dynamic recrystallization (DRX) accompanied by twinning. The 30Mn weld, which had the highest SFE, exhibited the highest recrystallization fraction (94.8 %) and an increasing rate of hardness (40.9 %). This is because a higher SFE can enhance dislocation mobility, leading to an active rate of continuous DRX as well as discontinuous DRX. Consequently, the refinement of the recrystallized grains effectively assisted the hardening of the 30Mn weld after FSW. Hence, we concluded that SFE should be considered to improve the properties of TWIP steels after FSW.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000529/pdfft?md5=e6671d015e66fa13f220e57320998bdb&pid=1-s2.0-S2666330924000529-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dario Croccolo , Massimiliano De Agostinis , Stefano Fini , Mattia Mele , Sayed Nassar , Giorgio Olmi , Chiara Scapecchi , Muhammad Yasir Khan , Muhammad Hassaan Bin Tariq
{"title":"Replacing non-renewable lubricants with vegetables oils in threaded joints","authors":"Dario Croccolo , Massimiliano De Agostinis , Stefano Fini , Mattia Mele , Sayed Nassar , Giorgio Olmi , Chiara Scapecchi , Muhammad Yasir Khan , Muhammad Hassaan Bin Tariq","doi":"10.1016/j.jajp.2024.100234","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100234","url":null,"abstract":"<div><p>Lubrication is essential to ensure the proper performance of threaded joints subjected to multiple tightenings. Previous research has investigated the effectiveness of various mineral and synthetic lubricants, but no studies have been conducted on those derived from renewable sources. In this study, the performances of sesame, sunflower, coconut, and castor oil are compared to traditional VG46 oil and MoS<span><math><msub><mrow></mrow><mn>2</mn></msub></math></span> grease. First, the rheological properties of the oils have been characterized. Then, tightening tests have been carried out to measure the coefficients of friction at the underhead and thread. The results demonstrate that vegetable oils outperform mineral VG46, especially in terms of repeatability. In particular, fractionated coconut oil exhibits exceptionally low coefficients of friction, which are not influenced by the tightening speed, unlike all other tested lubricants.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000505/pdfft?md5=0fe4881aa94d22efd195a455d7a99e71&pid=1-s2.0-S2666330924000505-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141479437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}