Top Region Research Articles

Four decades of full-scale nitrous oxide emission inventory in China.

China is among the top nitrous oxide (N2O)-emitting countries, but existing national inventories do not provide full-scale emissions including both natural and anthropogenic sources. We conducted a four-decade (1980-2020) of comprehensive quantification of Chinese N2O inventory using empirical emission factor method for anthropogenic sources and two up-to-date process-based models for natural sources. Total N2O emissions peaked at 2287.4 (1774.8-2799.9) Gg N2O yr-1 in 2018, and agriculture-developed regions, like the East, Northeast, and Central, were the top N2O-emitting regions. Agricultural N2O emissions have started to decrease after 2016 due to the decline of nitrogen fertilization applications, while, industrial and energetic sources have been dramatically increasing after 2005. N2O emissions from agriculture, industry, energy, and waste represented 49.3%, 26.4%, 17.5%, and 6.7% of the anthropogenic emissions in 2020, respectively, which revealed that it is imperative to prioritize N2O emission mitigation in agriculture, industry, and energy. Natural N2O sources, dominated by forests, have been steadily growing from 317.3 (290.3-344.1) Gg N2O yr-1 in 1980 to 376.2 (335.5-407.2) Gg N2O yr-1 in 2020. Our study produces a Full-scale Annual N2O dataset in China (FAN2020), providing emergent counting to refine the current national N2O inventories.

Consumers’ willingness to pay for local rice: Empirical evidence from Central Java, Indonesia

This study examines Indonesian consumers’ willingness to pay for local rice products as against commercial imports. We aimed to determine the consumer preference factors for local rice through a questionnaire survey and experimental auction in Surakarta and Sleman, two areas in the top rice-producing region of Central Java. The bidding price results of the three rounds of auction to determine the increasing nominal price for the local rice type, after information and tasting sessions, show the participants, as major rice consumers, confirming the highest interest in local rice, while displaying relatively less knowledge of the different rice varieties available in the markets. Most consumers evaluated both cooked and uncooked rice based on swelling and variety. The findings suggest the need to pay greater policy attention to local rice production and varieties, based on the preferences and attributes of the consumers.

Investigation of 300M ultra-high-strength steel deposited by wire-based gas metal arc additive manufacturing

300 M ultra-high-strength steel (UHSS) is widely used to produce landing gear components for aircraft. The conventional manufacturing route for these components involves extensive machining and significant material wastage. Here, the application of wire-based gas metal arc additive manufacturing to produce 300 M UHSS parts was investigated. In particular, the influence of torch shielding atmosphere on the process stability and material performance of 300 M UHSS was investigated. The shielding gases used for comparison are pure Ar, Ar with 2.5% CO2, Ar with 8% CO2, Ar with 20% CO2, and Ar with 2% CO2 and 38% He. It was found that the arc length decreased, the transfer mode changed from spray to droplet mode, and spattering became more severe as the CO2 proportion increased. Additionally, replacing Ar with He led to a broader arc core, and a slightly shorter arc length and maintained a spray transfer, which decreased spatter. The wall surface roughness followed the trend in spatter, becoming worse with the increasing CO2 proportion, and better with He addition. Adding CO2 and He in pure Ar significantly increased the bead and wall width. The microstructure and mechanical properties exhibited a strong location dependence in the as-built state, with fresh martensite and higher strength in the top region, and tempered martensite and better ductility in the reheated bulk. Generally, torch shielding gas composition appeared to have no significant effect on the microstructure evolution. This study provides a reference for the subsequent application of gas metal arc additive manufacturing to aircraft landing gear mass production to achieve a high deposition rate and process stability simultaneously.

Numerical simulation of impact process between spherical ice and a rigid plate based on the ordinary state-based peridynamics

Ice sphere impacts are an important issue in the study of composite materials, polar engineering, and aerospace engineering. The traditional mechanics numerical methods, rooted in classical continuum mechanics, like the Finite Element Method (FEM), grapples with the challenge of spatial derivatives not existing at the crack tip or crack surfaces, rendering it unsuitable for addressing discontinuity-related problems such as fracture and failure. Developed particle method peridynamics shows great ability in handling such discontinuous problems. This paper establishes an ice sphere impact model using the peridynamics method. To verify the accuracy of our model, we compared the simulated results with the tested results of the high-speed impacting ice sphere and obtained that the predicted impact load and crack propagation of ice spheres are consistent well with the experiment results. An isolated damage zone was found to appear at the top region when the surface crack just extends across the hemispherical plane. This phenomenon happens due to that the impact wave propagating along the sphere center axis reaches the top end faster than the surface wave, making spalling damage occurred at the top region, and the encounter between the reflected wave and the surface wave would make the spalling damage more severe.

Predictive value of DNA methylation patterns in AML patients treated with an azacytidine containing induction regimen

BackgroundAcute myeloid leukemia (AML) is a heterogeneous disease with a poor prognosis. Dysregulation of the epigenetic machinery is a significant contributor to disease development. Some AML patients benefit from treatment with hypomethylating agents (HMAs), but no predictive biomarkers for therapy response exist. Here, we investigated whether unbiased genome-wide assessment of pre-treatment DNA-methylation profiles in AML bone marrow blasts can help to identify patients who will achieve a remission after an azacytidine-containing induction regimen.ResultsA total of n = 155 patients with newly diagnosed AML treated in the AMLSG 12-09 trial were randomly assigned to a screening and a refinement and validation cohort. The cohorts were divided according to azacytidine-containing induction regimens and response status. Methylation status was assessed for 664,227 500-bp-regions using methyl-CpG immunoprecipitation-seq, resulting in 1755 differentially methylated regions (DMRs). Top regions were distilled and included genes such as WNT10A and GATA3. 80% of regions identified as a hit were represented on HumanMethlyation 450k Bead Chips. Quantitative methylation analysis confirmed 90% of these regions (36 of 40 DMRs). A classifier was trained using penalized logistic regression and fivefold cross validation containing 17 CpGs. Validation based on mass spectra generated by MALDI-TOF failed (AUC 0.59). However, discriminative ability was maintained by adding neighboring CpGs. A recomposed classifier with 12 CpGs resulted in an AUC of 0.77. When evaluated in the non-azacytidine containing group, the AUC was 0.76.ConclusionsOur analysis evaluated the value of a whole genome methyl-CpG screening assay for the identification of informative methylation changes. We also compared the informative content and discriminatory power of regions and single CpGs for predicting response to therapy. The relevance of the identified DMRs is supported by their association with key regulatory processes of oncogenic transformation and support the idea of relevant DMRs being enriched at distinct loci rather than evenly distribution across the genome.Predictive response to therapy could be established but lacked specificity for treatment with azacytidine. Our results suggest that a predictive epigenotype carries its methylation information at a complex, genome-wide level, that is confined to regions, rather than to single CpGs. With increasing application of combinatorial regimens, response prediction may become even more complicated.

Benincasa hispidas-inspired pore-gradient aerogel with integrated water and thermal management for highly efficient solar vapor generation and water purification

Engineering the pore structure of evaporator to effectively integrate water and thermal management is critical for efficient solar-driven interfacial vapor generation. Here, inspired by the unique structure of Benincasa hispidas, a bioinspired pore-gradient aerogel was fabricated for the first time. Experiments and numerical simulations reveal that the unique anisotropic porous structure of aerogel, which consists of small-pores at top region and large-pores at bottom region, enabling it to maximize the heat gains from the sunlight and localize the generated heat while provide adequate water supply concurrently. Under solar illumination (1 kW m−2), the fabricated aerogel can achieve a high evaporation rate of 2.49 kg m−2h−1, and the calculated energy efficiency is approximately 96.3 %, which is comparable to most of state-of-the-art evaporators. Additionally, with this aerogel employed, effective purification toward various undrinkable water can be achieved. This work derives from nature, providing us a design blueprint to integrate water and thermal management in a bulky material, and it is expected to advance one step further toward the design and practical application of high-performance solar evaporators.

Numerical analysis of the effect of an oscillating metal vapor plume on the keyhole and molten pool behavior during deep penetration laser beam welding

The effect of the oscillating metal vapor plume on the keyhole and molten pool behavior during the laser beam welding of AlMg3 aluminum alloys is investigated by experimental and numerical methods. The real-time height of the metal vapor plume is measured by high-speed camera observation. The obtained experimental results are used to evaluate the additional heating source and laser beam attenuation caused by the scattering and absorption based on the Beer–Lambert theory. Furthermore, the dynamic behavior of the metal vapor plume is incorporated into a 3D transient heat transfer and fluid flow model, coupled with the ray tracing method, for the laser beam welding of the AlMg3 alloy. It is found that additional heating resulting from the scattered and absorbed laser beam energy by the metal vapor plume significantly expands the shape of the molten pool on the top region. Moreover, the oscillating metal vapor plume caused the fluctuation of the high-temperature region in the molten pool. The probability of keyhole collapse at the bottom increases 17% due to the oscillating laser power induced by the laser beam attenuation. The internal interplay between the metal vapor plume, molten pool shape, and keyhole collapse is obtained. The developed model has been validated by experiments, which shows a good agreement.

Effect of process modes on microstructure and mechanical properties of CMT wire arc additive manufactured WE43 magnesium alloy

The traditional WE43 magnesium alloy (WE43-Mg) manufacturing process faces challenges in producing large and complex structures. The cold metal transfer wire arc additive manufacturing (CMT-WAAM) offers a promising solution due to its flexibility, high deposition efficiency and low heat put. However, energy transfer and mass transfer are highly coupled in the CMT additive manufacturing process. Under different working modes, the local thermal processes are quite different for the same transition metals, which can produce different microstructures and mechanical properties. Therefore, it is necessary to study the effect of working modes on microstructure and mechanical properties. This study successfully deposited single-pass multi-layer WE43-Mg components using four CMT processes: CMT, CMT-Pulse, CMT-Advance, and CMT-Pulse + Advance. The microstructure and mechanical properties of these deposited samples were compared. Results revealed equiaxed grains with uniform sizes in the top and middle regions, with fine-grain regions between layers in the four CMT modes. Compare the microstructure characterization results, the higher the line energy, the narrower the width of the remelted fine grain zone. Four CMT modes deposited components exhibited superior mechanical properties compared to as-cast WE43-Mg. The CMT pulse mode shows the best results due to its low porosity. The average yield strength is 149.0 MPa, tensile strength is 222.9 MPa, and elongation is 6.4 %.

CFD-DEM investigation of flow and heat transfer characteristics in a directly irradiated fluidized bed

The directly irradiated fluidized bed reactor has gained widespread attention due to its strong heat and mass transfer performance. However, there is still a lack of in-depth understanding of the gas–solid flow characteristics, heat transfer mechanisms, and flow pattern evolution in the fluidized bed. To address this, the computational fluid dynamics-discrete element method (CFD-DEM) was employed in this study to investigate the correlation between the flow pattern and the heat transfer path. The simulation results show that increasing the superficial gas velocity from the minimum fluidization velocity (umf) to 1.4umf induces a circulation pattern that significantly reduces the overheating phenomenon, resulting in a 40.52% decrease in the maximum particle temperature and a 74.59% decrease in the temperature standard deviation. The particle temperature increases in the top heat-collecting region, followed by thermal conduction and convection transferring the energy to low-temperature particles and fluid in the near-wall and bottom regions. As the superficial gas velocity increases, the proportion and frequency of particles entering the heat-collecting region increase, resulting in a more uniform temperature distribution within the bed. Taking into account factors such as heat transfer characteristics and fluidization energy consumption, a fluidization velocity of 1.6umf is recommended as the optimum operating condition for particles in this work, as it ensures a uniform temperature distribution within the bed and minimizes convective and radiative losses.

Laser directed energy deposition of Ti-1Al-8V-5Fe alloy: From zero to significant tensile plasticity

Titanium alloy Ti-1Al-8V-5Fe (Ti-185) has essentially remained an experimental alloy since its invention because of the formation of iron-stabilized beta-flecks in conventional manufacturing. Laser directed energy deposition (L-DED) has the potential to avoid this issue while realizing in-situ ageing. This work investigates the L-DED fabrication of Ti-185 alloy. We show that the precipitate phases along the build height of the Ti-185 plate sample have a decisive influence on its tensile properties. Due to the formation of the embrittling isothermal omega-phase (ωiso), the top region of the Ti-185 plate sample exhibited zero plasticity, while the middle region, which is free of the omega-phase (ω), demonstrated significant tensile ductility (20 ± 2 %) and strength (1042 ± 13 MPa). The formation of each phase is elucidated using simulated temperature evolution profiles in the plate sample. Furthermore, we show that converting the isothermal omega-phase into the athermal omega-phase (ωath) through beta-annealing and water quenching restores tensile ductility.

Binding Energy Stark-Shift, Polarizability and Dipole Moment Response of Shallow Donor Impurity in GaAs Quantum Dots

In this study, we have examined, under the influence of an electric field applied along the z-direction, the binding energy Stark-shift, the dipole moment and the polarizability of a confined shallow donor impurity in GaAs conical-shaped quantum dots (CSQD). With square infinite confinement system, the calculations are based on the approximation of the effective mass by using the finite difference method. Our results show that increasing the radius of the CSQD structure and the electric field intensity increases the Stark shift binding energy and it has a mixed behavior as a function of the impurity position. Furthermore, the polarizability and the dipole moment vary in a quasi-linear way as a function of the dot radius and they follow a decreasing function as a function of the electric field intensity. These two physical parameters have a double behavior, they decrease with the position of the impurity in the strong confinement regime and they increase in the top regions of the quantum dot. These results provide a lot of information about the behavior of the electronic wave function which give more interesting ideas for the fabrication of optoelectronic devices.

Microstructure gradient formation in electron-beam melting powder-bed fusion of a gamma-prime Ni-based superalloy

Microstructure gradient is formed during the additive manufacturing of Ni-based superalloy Haynes® 282® via electron-beam melting powder-bed fusion (EB-PBF) process. The precipitation of secondary phases occurs owing to EB-PBF in-situ heat treatment as consequence of high temperature powder bed pre-heating and multiple melting and re-heating thermal cycles, which can be summarised as a carbide precipitation heat treatment at 1000–1025 °C/8 h, aging between 875 and 975 °C/30 h, followed by a slow cooling step. Relatively large precipitates formed inter- and intragranularly with M3B2 boride and gamma-prime (γ') have sizes of approximately 5 μm and 110 nm, respectively, at the bottom of the build. The size of the precipitates decreases along the build direction. In the top region, the precipitate sizes of boride and γ' are 1 μm and 50 nm, respectively. MC carbide with a size of <1 μm precipitated throughout the build. A good correlation is observed in terms of the γ' size to hardness with average values of 350 HV at the bottom and 400 HV at the top. The ultimate tensile strength (UTS), yield strength (YS), and elongation (EL.) values at the bottom and top regions are 1080 ± 40 MPa, 805 ± 25 MPa, and 20 ± 5%; and 1105 ± 20 MPa, 825 ± 15 MPa, and 25 ± 5%, respectively. Overall, EB-PBF Haynes® 282® exhibits higher UTS and YS but lower EL than those of the as-received wrought alloy (950 ± MPa, 650 ± 15 MPa, and 40 ± 5%, respectively).

A non-invasive method for measuring time-series of moisture concentrations in mycelial blocks during shiitake mushroom development using magnetic resonance imaging

The moisture concentration in mycelial block is an important factor for increasing the yield of high-quality shiitake mushrooms (Lentinula edodes) with a pileus of 4–5cm or more in mycelial block cultivation. Here, we show a novel way to measure moisture concentration in mycelial blocks using magnetic resonance imaging (MRI). The culture medium was inoculated with Hokken No. 607 and mycelial blocks were incubated and their moisture concentration was measured using MRI. A method was developed to calculate the spatial distribution of moisture concentration inside the mycelial blocks by measuring the total water mass in the mycelial block using mass method and creating a calibration line. During the maturation phase of the mycelial block (46–98 days of incubation), the moisture concentration in the top region of the mycelial block decreased once at 66 days of incubation and then gradually increased. The increase in moisture concentration was due to mycelia decomposing the culture medium and producing water. During the growth period of the fruiting body, the moisture concentration in the periphery of the fruiting body increased and, conversely, the moisture concentration in the whole mycelial block decreased because water in the mycelial block moved into the fruiting body.

Optimum process parameters of IN718 alloy fabricated by plasma arc additive manufacturing using Taguchi-based grey relational analysis

The process parameters of IN718 alloy fabricated by plasma arc additive manufacturing (PAAM) were evaluated by Taguchi-based grey relational analysis, and the microstructure and mechanical properties of the PAAM alloy were analyzed to verify the optimized process parameters. The results show that the influence of each process parameter on the dilution ratio and forming coefficient is consistent. Based on the results of Taguchi-based grey relational analysis, the optimized process parameters for PAAM IN718 alloy are plasma arc current 115 A, scanning rate 1000 mm/min, powder feeding rate 16 g/min, and shielding gas flow 800 L/h. The plasma arc current and powder feeding rate play primary roles in the dilution rate and forming coefficient of PAAM IN718 alloy. With the optimized process parameters, the forming and internal crack of the PAAM IN718 alloy is controlled. The microstructure of PAAM IN718 alloy is dominated by temperature gradient and constitutional supercooling, which is sequentially transformed from cellular crystal in the bottom region to coarse columnar dendrite and equiaxed crystal in the top region. Laves phase exhibits a concentration gradient that gradually increases from top to bottom on the cross-section from the range 11.3–18.6 vol%. Due to the solid solution strengthening of Nb/Mo elements and dispersion strengthening by γ″ phase, the microhardness and tensile strength of PAAM alloy after full heat treatment reach about 500 HV and 1284 MPa, respectively. These are satisfactory mechanical properties compared to other additive manufactured IN718 alloys, and PAAM is suitable to prepare IN718 alloy to obtain favorable microstructure and mechanical properties.

Managing the inevitable microstructural and property heterogeneity in powder bed fusion Ti-6Al-4V parts via heat treatment

This study investigates the effects of the commonly-observed microstructure heterogeneity from the metal electron beam powder bed fusion (PBF-EB) processes and how it evolves following the associated heat treatment (HT), on the tensile behaviour of Ti-6Al-4V alloy. A strain gradient crystal plasticity finite element (CPFE) method is employed using physically-based dislocation mechanics to capture the microstructure-sensitive size effect. Microstructural characterization is performed using electron backscatter diffraction (EBSD) of the as-built and post-HT specimens, with measurements of grain morphology, phase, and texture extracted from the bottom and top regions of specimens, used to construct the CPFE models. The dual-phase CPFE model represents α (hcp) and β (bcc) basket-weave morphology, typical in Ti-6Al-4V, with accurate PBF-induced texture definitions defined directly from the measured EBSD data. Key microstructural features exhibiting a gradient include lath width and phase fraction. The effects of as-built microstructural gradient in a single component include an increase of lath width by 43 %, and the beta phase fraction, from bottom to top. The CPFE models successfully predict the effect of HT and microstructural gradient on tensile response, specifically yield stress and initial hardening rate. The role of dislocation density and the associated influence of lath width on yield stress are empirically correlated for the structure-property design of PBF-EB metals. This study also demonstrates the homogenising effect of the heat treatment; effectively eradicating the microstructural gradient observed in as-built specimens.

Achieving High Strength and Creep Resistance in Inconel 740H Superalloy through Wire-Arc Additive Manufacturing and Thermodynamic-Guided Heat Treatment.

Inconel 740H superalloy is commonly used in advanced ultra-supercritical power plants since it possesses excellent strength and creep resistance. This study investigates the microstructure and mechanical properties of Inconel 740H superalloy fabricated using wire-arc additive manufacturing. The as-printed microstructure consisted of columnar γ grains with the Laves phase and (Nb, Ti)C carbides as secondary phases. The anisotropy in grain structure increased from the bottom to the top regions, while the hardness was highest in the middle portion of the build. To guide the post-heat treatment design, thermodynamic and kinetic simulations were employed to predict the temperature and time. Complete recrystallization with the Laves phase dissolution occurred throughout the build after homogenization at 1200 °C for 2 h. The peak hardness was achieved after aging at 760 °C for 12 h with the M23C6 carbides decorating the grain boundaries and γ' precipitates in the grain interior. The yield strength (655 MPa) and ductility (29.5%) in the post-heat treated condition exceeded the design targets (620 MPa, 20%). Stress rupture tests at 750 °C showed that the high-temperature performance was at par with the wrought counterparts. The fracture mode after rupture was identified to be intergranular with the presence of grain boundary cavities along with grain boundary sliding.

Bubble behavior in a vacuum fluidized bed

Bubble behavior in a vacuum fluidized bed was investigated in this work. Experimental results showed that bubble diameter and rise velocity increased with declining the pressure, whereas bubble density decreased. The evolution of bubble density with bed height could be divided into three stages on the basis of the corresponding net-coalescence rates. The decrease in bubble density in the bottom region accelerated as the pressure decreased, whereas the increase in bubble density in the top region was gentle. Increasing the vacuum degree enlarged the variation in bubble size, resulting in the decline of operating stability in the fluidized bed. A new correlation that considered the effect of operating pressure on bubble behaviors exhibited accurate prediction in the vacuum fluidized bed. Bubble velocity was proportional to bubble diameter for small bubbles, and bed structure obviously affected the rise velocity of large bubbles. The distribution of the bubble aspect ratio was positively skewed and many bubbles had a tendency to become slender as the operating pressure decreased.

A novel directed energy deposition-arc method of deposition layer without focused thermal energy heating: droplet transfer, morphology and microstructure

Additive manufacturing (AM) of metal usually forms columnar grains along the building direction due to the focused thermal energy directly heating the deposition layer to easily obtain an obvious temperature gradient. The columnar grains are not conducive to AM-sample application, which results in the property anisotropy of the AM-sample. In this work, a novel directed energy deposition-arc (DED-Arc) method for depositing layers without direct heating by focused thermal energy is proposed. The arc burns between the tungsten electrode and a water-cooled electrode, were only used to melt the wire during DED-Arc process. Using stainless steel wire as a model alloy, by studying droplet transfer, morphology of the deposition layer and microstructure evolution, the feasibility of the method was fully verified. Two kinds of droplet transfer modes were observed, and the difference between them was whether the droplet contacted the molten pool before falling off. The focused thermal energy is only used to melt the wire, and the droplet transfer cycle is mainly affected by gravity, greatly decreasing the heat accumulation compared with existing methods. The heat-affected zone (HAZ) was obviously inhibited. The grain morphology of the deposition layer mainly consists of equiaxed crystals (∼300 μm) without an obvious preferred orientation. The deposition layer without direct heating by focused thermal energy could reduce the heat accumulation, resulting in a decrease in the temperature gradient and the morphology of equiaxed grains. The microstructure of a cylindrical sample was produced and has the same characteristics as with the deposition layer. The average microhardness of 172.63 HV, 167.95 HV and 169.26 HV are obtained in the top, middle and bottom regions, respectively. In addition, the tensile strengths are 500 MPa and 490 MPa, respectively.

On the flow unsteadiness and operational characteristics of a novel supersonic fluidic oscillator

A novel supersonic jet oscillating method is investigated both experimentally and numerically. A rectangular primary supersonic jet is issued into a confined chamber with sudden enlargement. Secondary control jets are issued from the top and bottom backward-facing step regions formed due to sudden enlargement. The primary jet is oscillated in the transverse direction by blowing the secondary jets in the streamwise direction in a pulsating manner with a phase shift. The out-of-phase secondary jet blowing causes the primary jet to periodically adhere to the upper and lower part of the confined chamber, causing flapping of the primary jet and acting as a supersonic fluidic oscillator. The supersonic jet oscillation characteristics are experimentally investigated using shadowgraph type flow visualization technique and steady and unsteady pressure measurements. Quantitative analysis of the shadowgraph images using the construction of y – t and y – f plots reveals the presence of periodic jet oscillation with a discrete dominant frequency similar to the secondary jet excitation frequency. The existence of linearity between the excitation frequency and the flapping jet frequency on the low-frequency (0.66–6.6 Hz) side is first proven experimentally. Later, the high-frequency (16.67–5000 Hz) operation extent of the supersonic fluidic oscillator is further demonstrated using unsteady computational studies owing to the existing experimental facility's limitations. A reduced-order analytical framework has also been proposed to investigate the limiting oscillation frequency. It is found that the limiting frequency predicted from the proposed analytical model shows fairly good agreement with the computationally predicted results (5 kHz).

Microstructural characterization of super duplex stainless steel fabricated using WAAM technique

In the present work, Robotic CMT based multilayered wall of super duplex stainless steel (SDSS) comprising 75 layers was fabricated using wire arc additive manufacturing (WAAM) technique. Microstructural studies were performed on different regions of the WAAM wall. Various morphologies of austenite namely, Widmanstätten austenite (WA), intragranular austenite (IGA), grain boundary austenite (GBA), and secondary austenite (SA) were observed in almost all the layers of the SDSS wall. Widmanstätten austenite (WA) was predominant in the top region of the wall while intragranular austenite (IGA) was leading in the transition region along with secondary austenite (SA). Secondary austenite was found in the bottom region of wall. Such transformation of different phases with different morphologies resulted into microhardness variation across different regions of the wall. The bottom region was 11.8% harder and the middle region was 5.85% harder than the top region of the wall. Based upon these results such as a close variation of microhardness across different regions, accompanied by sound quality and thermal stability of the WAAM wall, the welding procedure as reported in this work, can be recommended for industrial applications involving fabricating SDSS structures.