The design at the center of the study is a narrow slanted groove, a hybrid between the two conventional options that dominate thick-plate work. Traditional V-shaped or bevel grooves are forgiving but voracious: their wide openings demand large volumes of filler wire and heavy heat input, which drives up cost and accumulates thermal energy in the joint. Narrow-gap I-grooves sit at the opposite extreme, consuming minimal filler metal, but in horizontal welding they are notoriously prone to defects such as lack of penetration and solidification cracking. The slanted groove threads the needle. Its cross-sectional area falls between the two conventional geometries, cutting filler consumption well below bevel levels, while its inclined walls reshape the weld bead to suppress the cracking mechanism that plagues I-grooves.

The cracking problem is rooted in bead geometry. When the height-to-width ratio of a weld bead exceeds roughly one, the last-to-solidify liquid at the weld centerline becomes starved, unable to feed the shrinkage strains concentrating there. Columnar grains grow along the centerline, shrinkage stresses build, and hot cracks can tear through the semi-solid metal. Lowering that ratio below one improves liquid feeding and suppresses cracking. The slanted groove achieves exactly this by tilting the groove walls at 35 and 37 degrees, so the wire sits nearly parallel to the groove surface rather than the horizontal plane. That orientation places the welding position between conventional horizontal and flat welding, boosting penetration on the upper sidewall, which gravity and arc forces normally shortchange in horizontal work.

To test the concept, the researchers welded two 36-millimeter-thick plates of SN490B structural steel, each measuring 133.26 by 250 millimeters, using CO2-shielded arc welding with YGW18 wire in thirteen passes, with no preheating or post-weld treatment. Two transverse webs and a backing strip, all of the same steel, mimicked the restraint of a real structure. A thermocouple recorded the temperature history near the weld line throughout the process, and after welding the team measured angular distortion across four transverse sections using a flat reference plate and magnetic blocks. The average total transverse bending angle came out at 0.68 degrees, comfortably inside the one-degree acceptance limit for angular distortion in welded construction.

Mapping the residual stresses demanded heavier instrumentation. The team used the contour method, in which the specimen is sliced down the middle with wire electro-discharge machining, releasing the stress perpendicular to the cut and causing the surface to deform. A Keyence VR-5200 structured-light system scanned that deformed surface with ten-micrometer precision, and the measured displacements were fed into a finite element model to reconstruct the internal stress field. Because the contour method alone captures only one stress component, the researchers combined it with X-ray diffraction on electropolished measurement lines, an approach known as the extended contour method, to recover the full three-dimensional residual stress state on the cut surface.

The measurements told a consistent story. Longitudinal residual stress, running along the weld line, was high and tensile throughout the weld layers and the adjacent heat-affected zone, peaking at roughly 650 megapascals in the molten zone on the surface path, a consequence of constrained longitudinal shrinkage and heat accumulation inside the narrow groove. Moving away from the weld, the stress fell and turned compressive, and through the thickness it was highest near the top surface, where the final passes were deposited, declining toward the bottom. Transverse stresses were lower overall but still showed pronounced tensile peaks in the weld zone, with oscillations along the thickness path that trace the sequential thermal cycles of the thirteen individual passes.

On the computational side, the team built a three-dimensional thermo-elastic-plastic finite element model in JWRIAN, an in-house welding simulation code developed at Osaka University. The model contained about 61,000 nodes and 56,000 hexagonal solid elements, finely meshed in the weld zone and coarsening outward. An uncoupled thermal-mechanical scheme first computed the temperature history using a prolate-spheroid heat source with temperature-dependent material properties, then applied that history as a thermal load in an elastic-plastic large-deflection analysis. The simulated weld pool geometry matched the macro-etched cross-sections, and the calculated temperature at the monitored point tracked the measured curve closely across all thirteen passes.

One refinement proved decisive for stress prediction. Vickers hardness testing showed the molten zone to be harder than the base metal, while the heat-affected zone differed only slightly. The team translated those hardness ratios directly into yield-strength variations, raising the molten zone’s yield stress by roughly twenty percent across the temperature range while leaving the heat-affected zone essentially unchanged. Incorporating this hardness-based yield strength significantly improved the agreement between predicted and measured residual stresses in both the longitudinal and transverse directions, a practical demonstration that microstructural data can sharpen welding simulations without exotic material testing.

The simulated distortion also matched experiment, with a predicted average angular distortion of 0.53 degrees against the measured 0.68 degrees. Intriguingly, both revealed that the distortion is not symmetric about the weld line: the acute-angle side of the slanted joint rotated more than the obtuse side, because the inclined geometry converts symmetric shrinkage into asymmetric angular rotation, unlike conventional grooves. The finite element results further showed peak tensile longitudinal stress near the final passes of about 700 megapascals, compressive stresses of roughly minus 70 to minus 90 megapascals at mid-thickness to satisfy equilibrium, and Von Mises equivalent stress approaching the material’s yield strength of 458 megapascals near the last few passes.

Taken together, the results argue that the narrow slanted groove delivers a rare combination in thick-plate welding: sound welds free of the defects that plague I-grooves, filler consumption far below bevel-groove levels, distortion within standard acceptance limits, and residual stresses that are now quantitatively predictable. For industries joining thick steel in the horizontal position, from shipyards to offshore construction, the study offers both a practical groove design and a validated simulation workflow, complete with a hardness-informed material model, that could move straight from the laboratory into fabrication planning.

Subject of Research: Residual stress and deformation in horizontal multi-pass welding of thick steel plates with a narrow slanted groove

Article Title: Horizontal welding deformation and residual stress of narrow slanted groove for thick plates

Article References: Nour, M., Rashed, S., Ma, N., Agano, Y., Okumura, T., & Shibahara, M. (2026). Horizontal welding deformation and residual stress of narrow slanted groove for thick plates. Advanced Materials Joining, 1(1), Article 16. https://doi.org/10.1007/s44500-026-00020-1

Image Credits: AI Generated

DOI: 10.1007/s44500-026-00020-1

Keywords: welding, thick steel plates, narrow slanted groove, residual stress, angular distortion, contour method, X-ray diffraction, finite element analysis, multi-pass welding, solidification cracking, SN490B steel, hardness

The launch editorial, written by Yu Zhou of the School of Materials Science and Engineering at the Harbin Institute of Technology in China and Peter Mayr of the Chair of Materials Engineering of Additive Manufacturing at the Technical University of Munich in Germany, argues that joining technology and additive manufacturing are the fundamental enablers of some of humanity’s most ambitious engineering feats. The authors point to the multi-material airframes of next-generation airplanes, where lightweight alloys, titanium, and carbon-fiber composites must be bonded together without compromising strength or fatigue life. They highlight the micro-scale ultrasonic bonding required for the high-density battery packs powering the electric vehicle revolution, where thousands of delicate electrical interconnects must survive years of thermal cycling and vibration. In the medical device industry, specialized laser joining enables the fabrication of biocompatible titanium implants with the precision that surgical applications demand.

Perhaps the most striking example cited in the editorial comes from fusion energy, where dissimilar metal joints, such as connecting tungsten to copper, are crucial for plasma-facing components. Tungsten offers the highest melting point of any metal and can withstand the brutal particle bombardment inside a fusion reactor, while copper provides the thermal conductivity needed to carry heat away to power generation systems. Joining these two materials, whose melting points and thermal expansion behaviors differ dramatically, is one of the defining challenges of fusion engineering, and solving it will require exactly the kind of interdisciplinary joining science that the new journal intends to champion.

According to the editorial, the field is currently witnessing an era in which the development of advanced materials, including high-strength steels, high-entropy alloys, and metal or ceramic matrix composites, must be matched by equally advanced joining processes to unlock their full potential. High-entropy alloys, composed of multiple principal elements in near-equal proportions, offer extraordinary combinations of strength and toughness but defy conventional welding wisdom, because their complex chemistry produces unpredictable behavior in the molten pool during fusion welding. Ceramic matrix composites promise to revolutionize gas turbines and hypersonic vehicles, yet ceramics cannot be welded in the traditional sense at all, demanding entirely new approaches such as brazing with engineered interlayers or transient liquid phase bonding. The synergy between material innovation and joining science, the authors write, such as the use of nanoscale interlayers to mitigate thermal stresses or solid-state bonding to preserve the unique microstructure of additively manufactured parts, represents the new frontier of manufacturing.

The distinction between fusion and solid-state approaches is central to this frontier. Conventional fusion welding melts the materials at the joint, creating a cast microstructure that can be weaker and more defect-prone than the parent material. Solid-state welding techniques, including friction stir welding, diffusion bonding, and ultrasonic joining, never melt the material, instead using heat, pressure, and plastic deformation to create bonds while preserving the carefully engineered microstructures of modern alloys and printed parts. This matters enormously for additively manufactured components, whose as-built microstructures are often precisely what gives them their superior properties; melting them back down at the joint would erase those gains. Nanoscale interlayers, meanwhile, offer a route to manage the residual stresses that accumulate when materials with different thermal expansion coefficients are joined, a problem that grows more severe as engineers combine ever more dissimilar materials in a single structure.

The new journal, launched in 2026 with Zhou and Mayr as its founding editorial voices, is international, open access, and peer reviewed. Its scope encompasses all aspects of welding, joining, and additive manufacturing processes across a wide range of materials, including metals, ceramics, composites, and emerging material systems. The key topics listed in its instructions to authors read like a map of the field’s future: fusion welding, solid-state welding, brazing, soldering, hybrid welding and joining, and surfacing techniques; additive manufacturing of metals, ceramics, composites, and other advanced materials; AI-driven materials and process design; electronic packaging and interconnect technologies; micro- and nano-joining techniques and assembly; metallurgical and materials interactions associated with joining; welding physics; intelligent welding; welding modelling and simulation; structural integrity and performance of welded and additively manufactured components and structures in service; welding and joining in extreme environments such as space, underwater, and radiation settings; and the joining of advanced materials including ceramics, composites, and entropy-driven materials.

Several of these topics signal where the field is heading. AI-driven materials and process design promises to compress development cycles that once took decades, using machine learning to predict weld microstructures, optimize process parameters, and screen candidate filler materials before a single experiment is run. Intelligent welding, in which sensors and adaptive control systems monitor and correct the process in real time, is already transforming industrial practice by catching defects as they form rather than after the fact. Welding in extreme environments, from the vacuum of space, where astronauts must repair structures without the benefit of atmosphere, to the deep sea, where pressure and water complicate every thermal process, to the radiation fields of nuclear and fusion facilities, where robots must do the work humans cannot, pushes joining science into territory where failure is not an option. Electronic packaging and micro-joining, meanwhile, sit at the heart of the semiconductor and battery industries, where joints measured in micrometers determine the reliability of devices that billions of people depend on daily.

Accepted article types at Advanced Materials Joining include Research Articles, Reviews, Perspectives, Research Highlights, and Comments, giving the community multiple channels for sharing both comprehensive studies and rapid observations. The editorial board emphasizes that the journal aims to foster interdisciplinary collaboration and innovation, serving researchers, engineers, and professionals engaged in materials science, manufacturing, mechanical engineering, and related fields. The board members state that they are proud of the journal’s inauguration, which they say illustrates its potential in disseminating cutting-edge research that bridges the development of advanced materials with innovative joining techniques, and they express deep enthusiasm for the journal’s future while upholding the scientific integrity associated with the Springer Nature brand.

The open-access model is presented as essential to the journal’s mission. In a field characterized by rapid technological advancements serving urgent global challenges, the traditional barriers to scientific information can stifle progress, the editorial argues. By ensuring that critical breakthroughs are immediately and freely available to a global audience, the journal seeks to foster a truly collaborative environment in which academic researchers and industry professionals can share significant discoveries and practical insights without delay, thereby amplifying the real-world impact of their work. The timing is significant: as the demand for high-performance, sustainable, and intelligent structures pushes traditional joining methods to their limits, the gap between what materials can do and what joints can withstand has become a genuine bottleneck for the energy transition, electrified transport, and next-generation aerospace.

The editorial closes with an invitation to researchers, practitioners, and students from all corners of the world to contribute their best work to what the editors call a new home for the joining community, declaring that together the community has the opportunity to shape the future of advanced materials joining. For a discipline that has quietly underpinned every major industrial revolution, from the riveted hulls of the steam age to the friction-stir-welded rockets of the commercial space era, the arrival of a dedicated, open, and forward-looking publication venue marks a moment of consolidation and ambition. The first volume’s inaugural article makes the case that the next century of engineering will be decided not only by the materials we invent, but by our ability to join them together reliably, efficiently, and intelligently.

Subject of Research: The launch of the open-access journal Advanced Materials Joining covering welding, joining, and additive manufacturing science for advanced materials.

Article Title: Shaping the future of joining: introducing Advanced Materials Joining

Article References: Zhou, Y., & Mayr, P. (2026). Shaping the future of joining: introducing Advanced Materials Joining. Advanced Materials Joining, 1(1), Article 1. https://doi.org/10.1007/s44500-026-00008-x

Image Credits: AI Generated

DOI: 10.1007/s44500-026-00008-x

Keywords: Advanced Materials Joining, welding, joining technology, additive manufacturing, solid-state welding, high-entropy alloys, dissimilar materials, fusion energy, micro-joining, open access journal, Springer Nature, structural integrity

The origins of the field reach back to the 1960s, when International Nickel Company first dispersed thorium oxide into nickel to create the TD-Ni alloy, an innovation that moved dispersion strengthening from theory into practice. By the early 1970s, the company had adopted mechanical alloying to distribute yttria particles uniformly through the alloy, igniting the rapid development of the ODS family. Traditional superalloys derive their strength from precipitation and solution strengthening, allowing long service at roughly 760 to 1100 degrees Celsius, but above that range the critical nickel aluminide strengthening phase coarsens and dissolves. ODS superalloys sidestep this ceiling entirely. Their oxide particles, with melting points as high as 2410 degrees Celsius for yttria and 2050 degrees Celsius for alumina, remain stable deep into the temperature regime where nothing else survives, making the alloys prime candidates for turbine components, nuclear reactor internals, and other extreme environments.

The strengthening chemistry is elegantly precise. Yttria particles interact with the nickel matrix through remarkably small lattice mismatches, with interplanar spacings differing by only fractions of a nanometer, allowing a cohesive interaction between particle and matrix. Studies comparing yttria and alumina dispersoids in nickel-chromium substrates found the two particles contribute to strength in distinct proportions: yttria relies mainly on Hall-Petch grain refinement and Zener pinning, while alumina contributes predominantly through Hall-Petch strengthening. Dispersion strengthening itself operates through the Orowan mechanism, in which dislocations must bypass immobile particles, leaving loops behind and consuming energy. The strengthening increment scales with the square root of particle volume fraction and inversely with particle radius, which is precisely why the fate of those particles during welding matters so enormously. When particles grow or vanish, the strength advantage evaporates.

The review identifies three interlocking challenges that have limited the engineering deployment of ODS welded joints. The first is the evolution of the oxide particles themselves under welding thermal cycles. Research on friction stir welding of the alloy MA956 documented significant particle agglomeration, with average oxide particle diameters growing from 10.6 nanometers in the base metal to 18.4 and 19.7 nanometers at medium and high heat inputs respectively. Raising tool rotation speed and slowing travel speed intensified the effect, because greater heat input promotes both particle decomposition and increased churning. In fusion welding the problem becomes acute: at molten pool temperatures yttria can decompose into dissolved yttrium and oxygen, which then react with aluminum or titanium in the matrix to form impurity phases, or segregate to grain boundaries and fusion lines, destroying both the Orowan strengthening and the Zener pinning that keep grains fine.

Remarkably, the particles prove unstable even under conditions that are not primarily thermal. In one striking study, friction stir welded MA956 was irradiated with 5 MeV iron ions at doses of 50 to 200 displacements per atom at temperatures between 400 and 500 degrees Celsius. Irradiation barely affected the base metal, but in the weld zones the particle diameter distributions broadened and the peaks shifted to larger sizes, with Ostwald coarsening dominating at 500 degrees Celsius. This means welded ODS components can degrade in service through radiation-enhanced diffusion alone, a sobering finding for reactor designers who count on these alloys to withstand decades of neutron bombardment. The particles, it turns out, are on the move under almost any energetic environment a welded joint will encounter.

The second major challenge is porosity, and here the review reveals a cruel irony. The same Zener pinning that stabilizes fine grains also immobilizes grain boundaries, which normally serve as escape routes for dissolved gases. Trapped gas accumulates into ellipsoidal pores that cluster along the pore walls alongside agglomerated oxide particles. Experiments with pulsed laser welding of ODS Eurofer steel showed large pores and incomplete penetration at short pulse durations, and residual micro-voids even when full penetration was achieved. Comparisons between argon arc welding and electron beam welding of MGH956 found the vacuum-based electron beam process produced fewer pores, since no shielding gas became trapped and the vacuum environment aided gas removal, yet porosity persisted even under vacuum. Molten pool fluid dynamics adds another layer of complexity: in gas tungsten arc welding, Marangoni convection ferries gas to the fusion line, producing chain-like pore distributions, while in laser welding recoil pressure acts directly against gas escape, and the elevated melt viscosity caused by particle pinning makes matters worse.

Third, the review catalogs the degradation of long-term service behavior rooted in residual stress. Because ODS superalloys possess extremely high yield strength, welding residual stresses frequently reach or exceed the yield point of the base material, and the alloys’ particle-pinned dislocation structures resist the relaxation mechanisms that ordinary alloys exploit. Neutron diffraction measurements of friction stir welded MA956 found longitudinal stresses far exceeding transverse stresses, with residual stress in the thermomechanically affected zone reaching as much as 80 percent of the base material strength, and 40 to 50 percent of yield strength at the stir zone center. The consequences are measurable in service: high-temperature fatigue tests of diffusion-bonded joints between ODS alloy MA758 and conventional superalloys showed roughly a 20 percent fatigue strength reduction at 950 degrees Celsius, while creep testing of friction stir welded MA754 revealed significantly reduced creep resistance, though a post-weld heat treatment that coarsened the grain structure partially restored it.

Against these challenges, the review weighs three families of remedies, each with genuine but incomplete power. Process parameter optimization delivers the most mature results in friction stir welding, where defect-free joints in MA754 were achieved at a tool rotation rate of 1000 rpm and a traverse speed of 50.8 millimeters per minute, and where a pseudo-heat index of 100 to 150 was identified as the threshold for fully fused, defect-free welds in MA956. Laser welding of PM1000 achieved optimal quality at heat inputs of 24 to 36 joules per millimeter, and selective laser melting of FeCrAl-ODS alloy reached porosities as low as 0.5 percent with carefully tuned laser power, scanning speed, and hatch spacing. Composition design offers a complementary route: adding filler powders rich in oxide-forming elements to laser welds regenerated fine, uniformly distributed oxide particles in the weld metal, simultaneously raising tensile strength and hardness. Post-weld heat treatment can transform brittle quenched martensite into tempered martensite and restore impact toughness, but it faces a fundamental contradiction, because the temperatures that relieve residual stress also threaten the oxide particles that give the alloy its purpose.

The review closes with a forward-looking agenda that reads like a wish list for the next decade of materials engineering. Novel welding wires could synthesize oxide particles in situ during joining, replenishing what the thermal cycle destroys. In-situ characterization techniques, including transmission electron microscopy coupled with microcalorimetry and synchrotron X-ray imaging, could finally let researchers watch particle coarsening and pore evolution in real time rather than inferring them from post-mortem micrographs. Full life cycle performance databases under combined high temperature, irradiation, and pressure would enable predictive lifetime models for welded components. And artificial intelligence, trained on the fragmented and often incomparable studies that already exist, could rapidly navigate the vast process parameter space to find windows that simultaneously preserve oxide particles, suppress porosity, and control residual stress. For the nuclear reactors, hypersonic vehicles, and next-generation turbines that depend on these remarkable alloys, cracking the welding problem may prove as consequential as inventing the alloys themselves.

Subject of Research: Weldability, oxide particle stability, and welding process optimization of oxide dispersion-strengthened superalloys

Article Title: Weldability and welding technology of oxide dispersion-strengthened (ODS) superalloys: a review

Article References: Weldability and welding technology of oxide dispersion-strengthened (ODS) superalloys: a review. (n.d.). https://doi.org/10.1007/s44500-026-00003-2

Image Credits: AI Generated

DOI: 10.1007/s44500-026-00003-2

Keywords: ODS superalloys, welding, oxide dispersion strengthening, friction stir welding, laser welding, yttria nanoparticles, Zener pinning, porosity defects, residual stress, nuclear materials, aerospace alloys, post-weld heat treatment