Metal Grain Size Research Articles

Imaging the microstructure of lithium and sodium metal in anode-free solid-state batteries using electron backscatter diffraction.

'Anode-free' or, more fittingly, metal reservoir-free cells could drastically improve current solid-state battery technology by achieving higher energy density, improving safety and simplifying manufacturing. Various strategies have been reported so far to control the morphology of electrodeposited alkali metal films to be homogeneous and dense, but until now, the microstructure of electrodeposited alkali metal is unknown, and a suitable characterization route is yet to be identified. Here we establish a reproducible protocol for characterizing the size and orientation of metal grains in differently processed lithium and sodium samples by a combination of focused ion beam and electron backscatter diffraction. Electrodeposited films at Cu|Li6.5Ta0.5La3Zr1.5O12, steel|Li6PS5Cl and Al|Na3.4Zr2Si2.4P0.6O12 interfaces were characterized. The analyses show large grain sizes (>100 µm) within these films and a preferential orientation of grain boundaries. Furthermore, metal growth and dissolution were investigated using in situ electron backscatter diffraction, showing a dynamic grain coarsening during electrodeposition and pore formation within grains during dissolution. Our methodology and results deepen the research field for the improvement of solid-state battery performance through a characterization of the alkali metal microstructure.

ESTIMATION OF THE AVERAGE GRAIN SIZES IN METAL AND THEIR DISPERSION BY CHANGING THE AMPLITUDES OF BOTTOM ECHOES OF LONGITUDINAL WAVES WITH A DIFFERENT NUMBER OF REFLECTIONS

A model (algorithm) has been developed for estimating the average size of a metal grain and the spread of its magnitude (standard deviation) according to experimental values of attenuation coefficients due to scattering of longitudinal waves on grains determined by the ratio of the amplitudes of bottom echoes (of the first and higher order) at three frequencies using a table of values of the difference between experimental and calculated values of attenuation coefficients. Computer modeling of the pulse amplitude differences of the 1st and 3rd bottom echoes for normal probe models with nominal frequencies of 5.0, 7.5 and 10.0 MHz and two variants of grain parameters used to test the specified algorithm has been carried out. The results obtained make it possible to choose the optimal operating frequency for metal control by a normal probe based on the estimated value of attenuation of longitudinal waves, determined by the average size of metal grains and the value of its magnitude spread.

SiO2-bearing Fluxes Induced Evolution of γ Columnar Grain Size

Understanding the controlling mechanisms of γ columnar grain size in the weld metal of low-carbon, low-alloy steel is critical for optimizing resultant microstructures and the weld metal’s ensuing properties. Here, we investigate the role of welding flux composition upon the γ columnar grain size by submerged arc welding of EH36 shipbuilding steel with designed CaF2-SiO2 fluxes. We found that the addition of SiO2 from 5 to 40 mass-% increases average columnar grain size by a factor of nearly 2.5, which results from the change of the weld pool solidification mode from peritectic to primary δ solidification. Such a change is directly related to element transfer behaviors between the flux and the weld metal. Furthermore, we offer compelling evidence that alterations in γ columnar grain size are not primarily governed by significantly populated inclusions and/or weld metal macro-morphological changes. Our findings may largely serve as a viable strategy toward designing welding consumables to match base metals to ensure the soundness of the weldment.

Effect of grain size of nanocrystalline metals on the loss modulus

The unique distribution of grain boundaries (GBs) and grains in nanocrystalline metals makes it interesting to study the mutually exclusive properties of modulus and damping. This study carried out large-scale calculations about the grain size effects through molecular dynamics and comprehensively analyzed the static modulus and damping properties of nanocrystalline metals using the loss modulus as the merit value. The research reveals that as grain size increases, the dissipation in polycrystalline metals transitions from being dominated by GB sliding in small grains to being jointly dominated by GB sliding and intragranular dislocation in larger grain structures. This transition is similar to the one observed in plastic flow stresses in nanocrystalline materials under finite deformation, i.e., the transition from the inverse Hall-Petch mechanism to the Hall-Petch mechanism. The mechanistic conversion of these two dissipations is demonstrated by quantitative characterization. This study is instructive for the mechanical design and development of nanocrystalline metals.

Multi-scale surface folding in metal cutting

In this work, commercially pure small-grained copper is used to investigate the nature of plastic flow through in situ image analysis supported by extensive electron backscatter diffraction characterization of the chip. Non-laminar sinuous flow, manifested with surface perturbations (bumps) and folds, produces a highly heterogeneous strain field during cutting. A series of mushroom-shaped morphology, termed as large bumps, separated by large folds on the free surface of the chip are captured in high-resolution field emission scanning electron microscopy. Large bumps or folds, captured in the high-speed camera, consist of many medium and small-size bumps. While the size of the small bump is comparable with the grain size of the base metal, a cluster of grains takes part in forming medium-size bumps. The pinning points for the small size bumps are either grain boundary or hard grains. The hard grains also act as pinning points for the medium size bump. The bump boundaries (folds) are characterized by higher strain and greater refinement of grains, whereas, less strain and larger elongated grains are the characteristics of the central region of the bumps. The evolution of different length scale features on the free surface is discussed in terms of the orientation of grain, position of the grains on the surface, and induced strain in the chip. This study suggested that the development of folding at different length scales is capable of providing deeper insight into the formation of a wide variety of chip morphology observed during the cutting of metals.

Laser welding of ultra-high strength steel rocket engine shell

The microstructure and mechanical properties of 30Cr3-30CrMnSiA ultra-high strength steel rocket engine shell welded joint were investigated in detail. The results indicated that the microstructure of the fusion zone was martensite of columnar and equiaxial due to the fast cooling rate of the laser welding. At the as-weld (AW) state, the average grain size of the 30Cr3 base metal was 4.63 μm, which was much smaller than that of the 30CrMnSiA base metal, which averaged 6.85 μm. After the post-weld heat treatment (PWHT), all the microstructures of the base metal, fusion zone and heat affected zone (HAZ) of 30Cr3 were tempered martensite. Meanwhile, at both AW and PWHT state, the tensile specimens of the welded joints of dissimilar materials were all fractured in the 30CrMnSiA base metal side at both 25 °C and 800 °C. After the PWHT, the tensile strength of 30CrMnSiA and 30Cr3 base metal at 25 °C were 1517.4 MPa and 1795.3 MPa, respectively. The welded joints of dissimilar materials by laser welding also showed excellent tensile properties at high temperature (800 °C), because of the small average grain size.

A novel optimizing Pulsed Plasma Gas Variable Polarity Plasma Arc Welding (PPG-VPPAW) method for improving weld quality

To enhance the reliability of aluminum alloy welding quality, a novel Pulsed Plasma Gas Variable Polarity Plasma Arc Welding (PPG-VPPAW) system is proposed. This system enables independent control and rapid adjustment of the plasma gas, allowing for flexible modulation of arc pressure output under constant thermal conditions, thereby reducing porosity and refining grain structure. The research analyzed the impact of parameters of different plasma gas on arc characteristics, welding porosity, and welding microstructure. The results reveal that the periodic changes in pulsed plasma gas induce corresponding variations in arc temperature, arc shape, arc pressure, arc voltage, and the morphology of the weld pool keyhole. The magnitude of the difference between the base value and peak value of pulsed plasma gas determines the extent of arc pressure fluctuations and the behavior of the backside keyhole. The maximum oscillation amplitude of the backside keyhole can reach up to 4.5 mm². Additionally, the oscillation of pulsed plasma gas within the molten pool has been demonstrated to effectively reduce weld porosity and refine grain size. Under this process, the grain size of the weld metal can be reduced by up to approximately 25%. Current work provides an important direction for fabricating highly reliable aluminum alloy weldments.

One-sided friction stir welding of 1565сhM alloy plates

The results of experimental studies of the features of the structure of butt joints of 1565chM alloy plates with a thickness of 25 mm obtained by one-sided friction stir welding are presented. It is established that the structure of the mixing zone (weld metal) is a dynamically and primarily recrystallized region. The grain size in the weld metal varies depending on the distance from the front surface of the weld from 5.16 μm (upper part of the joint) to 2.93 μm (root part of the joint). The separation of intermetallic compounds in the mixing zone for Al—Mg system alloys helps to reduce the average grain size. In the bodies of grains at the level of half the thickness of the plate, there are both chaotically distributed dislocations and dislocation clusters mainly in the form of dislocation walls. In this case, the scalar density of dislocations at this level exceeds the values of the scalar density of dislocations in the upper and root parts of the weld. In the mixing zone of the joints of the 1565chM alloy plates the microstructure at different levels of horizontal sections along the thickness of the plate is very homogeneous, which indicates the mechanism of layer-by-layer transfer, which is macroscopic.

Microstructural features and hot tensile behaviour of tungsten inert gas welded TP321 nuclear tubes at elevated temperatures

Austenitic stainless steel (ASS) tubes, specifically TP321, are widely used in nuclear reactors and heat exchangers due to their excellent strength, toughness, and corrosion at ambient and elevated temperatures. The microstructure observed in the TP321 weldment reveals the existence of equiaxed dendrites, along with delta ferrite and TiC precipitates within the austenitic matrix. Electron backscatter diffraction (EBSD) scans confirm differences in texture, grain size, and grain misorientation distribution in the weld metal (WM), heat-affected zone (HAZ), and base metal (BM) regions of the weldment. The EBSD texture at the WM zone is strong in the 〈0 0 1〉 fiber direction, consistent with the face-centered cubic structure of the TP321. Hot tensile tests were conducted on BM and WM samples at 450 °C, 550 °C, 650 °C, 700 °C, 850 °C, and 900 °C using a Gleeble 3500 simulator. The yield strength (YS), ultimate tensile strength (UTS), and percentage elongation (EL) exhibited a decreasing trend with the rise in test temperature. The strain hardening capacity (Hc) of both BM and WM decreases with increasing test temperatures due to enhanced dislocation movement. The strain hardening exponent, ‘n’ was determined for BM and WM through suitable fitting of stress–strain curves using the Hollomon equation and depicted a decreasing trend with rising test temperatures. The fractured samples are subjected to scanning electron microscope (SEM) analysis to investigate the failure mechanism. Fractography of the fractured samples reveal the presence of micro voids and dimples, supporting the ductile nature of the rupture.

Hybrid influences of interphase and grain-size on material responses of CNT-reinforced metal matrix composites

In this investigation, a theoretical model is developed to consider the coupled influence of interphase and grain-size of metal on the nonlinear response of CNT-reinforced MMCs. A multiscale theoretical framework based on the energy-based effective strain method and the field fluctuation method is established. The second-order stress moment and dislocation density model are also adopted to predict the entire grain-size dependent stress-strain relations. The energy-based effective strain method is proposed to better exhibit the energy stored in the three-phase composites by replaced average-strain. The microstructure variables include volume fraction, moduli of interphase, geometrical size factor, aspect ratio of CNTs, and grain size in metal matrix. The accuracy of the present predictions is verified by some available experimental data. As a result, the proposed model can be used to define the mechanical behavior and make an optimum design of CNT reinforced MMCs as well as advanced engineering composites.

Crystal plasticity-based analysis and modelling of grain size and strain path dependent micro-scaled deformation mechanisms of ultra-thin sheet metals

Multi-stage microforming is increasingly used in manufacturing of the miniaturized parts with complex structures and geometries. Optimization design of this type of manufacturing process, however, is still challenging due to its unknown intrinsic nature of the process. In the multi-stage deformation and microforming, the size effect (SE), the strain path change (SPC), and the intragranularly misoriented grain boundary (IMGB) generated in previous forming stage, are the main factors governing the deformation behaviors of ultra-thin sheets. To gain thorough insights into their influences on deformation and elucidate the associated micro-scaled mechanisms, SS 316L ultra-thin sheets with the thickness of 0.1 mm and different mean grain sizes (d¯) were used for two-stage tensile tests under the conditions with distinct pre-strain εpre and intersection angle θSPC (the angle between the previous loading direction and subsequent one). Mechanical tests reveal that increasing εpre and θSPC reduces the yield stress and hardening rate in SPC tension, but this reduction gets smaller after increasing d¯. This is because more IMGBs with complex pattern are formed in relatively large grains, raising the permanent deformation resistance inside grains in subsequent tension. To model the IMGB-induced hardening, the SPC-induced softening, and the SE-induced concurrent facilitations to the hardening and softening, an enhanced crystal plasticity constitutive relation was established. The physical essence that IMGB obstructs dislocation movement, is used to model the IMGB-induced hardening based on the interactions between the main slip planes and IMGBs. The hardening facilitation caused by increasing grain size is implicitly incorporated in determining the saturated slip resistance. Modelling of the SPC-induced softening is based on the high Schmid factor grain fraction and its influences are governed by pre-strain and the defined SPC parameter. The softening facilitation caused by coarsening grains is modelled in establishing the initial slip resistance in SPC deformation. The proposed simulation procedure and constitutive relationship help with accurately predicting the mechanical response and microstructure evolution in micro-scaled SPC deformation, and also provide a basis for modelling and design of the multi-stage microforming of complex miniaturized parts.

Effect of high intensity pulsed magnetic field (30 T) on microstructure and tribological properties of Ni-based coatings

Pulsed magnetic fields can improve ferromagnetic and paramagnetic materials by improving their stress structure, domain variation, phase structure distribution and grain size of both solid and molten metals. Therefore, we strengthened the Ni-based wear-resistant coating by using the high-intensity (30 T) pulsed magnetic field equipment independently developed by our research group. The results show that the magnetic domains appeared as sheet domains and showed sinusoidal distribution after pulsed magnetic field intensification. The crystal structure is improved, the residual compressive stress is increased and the tribological coefficient is decreased. This study provides a new perspective on the design of high-strength metal base coatings for various applications.

Investigation of mechanical and microstructural properties in joining dissimilar P355GH and stainless 316L steels by TIG welding process

In this study, the joining of high-temperature and pressure-resistant P355GH and austenitic stainless 316L steels by the Tungsten Inert Gas (TIG) welding method was investigated in terms of microstructure, mechanical properties, and weld efficiency. Comprehensive tests were carried out for the weld zone, heat-affected zones (HAZ), and base metals. In metallographic characterization research, optical microscope (OM), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX/EDS), X-ray diffraction (XRD), and EBSD analyses were performed. Average grain size and IPF (Inverse Pole Figure) map were determined from the EBSD analysis of P355GH steel, welded zone, heat-affected zones (HAZ), and 316L steel. Vickers microhardness, bending, Charpy V-Notch impact, and tensile tests were performed to determine the mechanical properties of the welded joint and the base materials. According to the EBSD results, the average grain size of the P355GH base metal was 5.13 ± 1 μm, the average grain size of the 316L base metal was 16.33 ± 5 μm, and the average grain size of the weld center was 10.09 ± 6 μm. As a result of XRD analysis, the delta ferrite phase was determined in the microstructure of the welding region. The highest Vickers microhardness value was determined as 268 ± 15 HV at the weld center. In the tensile test results, the highest tensile strength observed in the transverse weld joint was 593.92 ± 06 MPa and rupture occurred in the 316L region. Bending forces were measured as 34.331 ± 10 kN and 32.966 ± 11 kN for transverse and longitudinal welded samples, respectively. The TIG welding process showed superior properties such as toughness, high plastic deformability, and high weld efficiency of 101.89% in the joining of 316L and P355GH materials.

Effect of Semi-Aging Heat Treatment on Microstructure and Mechanical Properties of an Inertia Friction Welded Joint of FGH96 Powder Metallurgy Superalloy

Inertia friction welded joints often present different microstructures than the base metal, and subsequent heat treatment processes are always needed to maintain superior performance. This study investigates the effect of semi-aging heat treatment after welding on the microstructure, residual stress, micro-hardness, and tensile properties of inertia friction welded FGH96 powder metallurgy superalloy using optical microscopy, scanning electron microscopy, X-ray diffraction, and hardness and tensile tests. The results show that the semi-aging heat treatment after welding does not affect the grain size or grain morphology of the base metal. However, the recrystallization process can be further promoted in the weld nugget zone and transition zone. Meanwhile, the grain size is refined and the residual stress is significantly reduced in the welded joint after the same heat treatment. Under the synergetic strengthening effect of the γ′ phase, semi-aging heat treatment increased the micro-hardness of the weld nugget zone from 470 HV to 530 HV and improved the average tensile strength at room temperature by 118 MPa. These findings provide a reference for the selection of the heat treatment process after inertia friction welding of nickel-based powder metallurgy superalloys.

A comparative study on the mechanical behavior of S355J2 steel repair-welded joints

The mechanical behavior of repair-welded joints was particularly important for the service safety of steel structures. The microstructure and mechanical behavior of S355J2 steel base metal, welded and repair-welded joints were investigated in this paper. The low cycle fatigue tests on S355J2 steel base metal, welded, and repair-welded joints were conducted fully reversed with strain amplitudes varying from ±0.2% to ±1.1%. The results found that the microhardness of repair-welded joints decreased by about 20 HV with the growth in grain size of weld metal and heat-affected zone. Both elongations of welded and repair-welded joints were reduced by about 25.1% compared with the base metal. Considering the cyclic loading behavior, S355J2 steel base metal, welded, and repair-welded joints exhibited continuously softened, while the repair-welded joints exhibited a greater amount of softening than welded joints. Based on the Coffin-Manson equation, the decreased ratio of permissible total strain amplitude of repair-welded joints was significantly higher for medium and high cycle fatigue (> 104) compared to low cycle fatigue (< 104). The low cycle fatigue fracture surface shows that the defects in the repair-welded joints were the fatigue crack initiation position, but the S355J2 steel base metal and welded joints were initiated on the surface of the specimen.

The Strength Material Welding Dissimilar of Method GTAW AISI 1045 With HSS for Application Milling Tool

Dissimilar welding is a permanent joining of two dissimilar materials as the application of this welding is used in milling tools that receive a large load when used. It is certain that there is a change in the microstructure between the HAZ (Heat Affective Zone) regions, and causes a decrease in the strength of the material, because residual stresses, defects, and cracks due to dissimilar welding will become a problem in itself. This study will connect two different materials between AISI 1045 and HSS (High Speed Steel), using the GTAW (Gas Tungsten Arc Welding) welding method. Welding results from tensile strength, hardness and microstructure inspection as well as calculating grain size in the weld metal, HAZ and base metal areas are the focus of the analysis.&#x0D; This dissimilar welding will compare three welding amperes that is, ±110A, ±167A and ±225A. This amperage is used based on the welding results that have been carried out for both materials with the AWS standard for circular welding of solid round materials such as the shape of a milling tool. GTAW welding method is very good and strong, but the hardness of the weld metal is large and will cause brittleness. The difference in hardness between weld metal and HAZ is significant due to the rapid heat input resulting in failure in the area between weld metal and HAZ.&#x0D; Tensile test results for amperage ±110A tensile strength 84.70 kgf/mm2, the hardness is 665.58 HV in the HAZ area of HSS material. Examination of the microstructure in this area has austenite, martensite and carbide phases, it looks less than ±167A of amperage welding, the results of the hardness test are 774.70 HV in the HAZ area of HSS material so that this area will be more brittle. The smaller the grain size, the higher the hardness. Selection of dissimilar welding filler metal produces good joint strength. While the amperage welding of ±225A broke on welded metal with a tensile strength of 43.41 kgf/mm2, the hardness in the HAZ area was made of HSS with a hardness of 772.37 HV. The smallest hardness value is in the base metal area of AISI 1045 material with a hardness of 264.45 HV. The difference in hardness is much different between HSS and AISI 1045, indicating the use of filler metal with poor connection strength for large amperes.

Nano Mechanical Characterization and Physical Modeling of Plastic Deformation Chapter 2: Strengthening Mechanisms by Various Lattice Defects

Mechanical behaviors of metallic materials in a small scale are characterized and physically modeled based on experimental measurements and computational simulation. An effect of in-solution carbon or silicon in Fe on a plasticity initiation was characterizes by nanoindentation pop-in phenomenon. A coherency at a ferrite-cementite interface significantly affects to a plasticity initiation leading to a different macroscopic yielding behavior. A stability of an austenite phase in TRIP steel was evaluated though the analysis of indentation-induced deformation behavior, demonstrating a significant constraint effect on stabilization by an adjacent harder phase. Heterogeneous microstructures with a bimodal grain size in fcc metals show an inhomogeneous mechanical behavior depending on a location of the fine microstructure. An intermittent plasticity in pure iron was analyzed through a statistical model showing a Gaussian function by thermally activated process in the early stage and a power-law one by an avalanche type phenomenon in the subsequent stage. An elementally step in a plastic deformation in a metallic glass was characterized through Molecular Dynamics simulation indicating that the plasticity inhomogeneity depends remarkably on the initially inhomogeneous atomistic structure.

Overcoming strength–ductility trade-off of nanocrystalline metals by engineering grain boundary, texture, and gradient microstructure

The strength–ductility trade-off has been a long-standing dilemma for polycrystalline metals. Though many strategies such as introduction of gradient and twinned microstructure have been proposed to overcome the strength–ductility trade-off of nanocrystalline (NC) metals, a higher strength–ductility synergy is always called for. Here schemes taking advantage of texture engineering with incorporation of grain boundary (GB) strengthening and gradient microstructure design are proposed to achieve a more desirable strength–ductility synergy. Taking into account the size-dependent storage of dislocations in grains, GB sliding, and evolution of the void volume fraction, crystal plasticity finite element simulations incorporating the Gurson-type model are performed to reveal the mechanisms underlying the low ductility and strength–ductility trade-off of NC metals. Low GB strength and nonmonotonic variation of dislocation storage ability with respect to the grain size are revealed as the dominant factors responsible for the low ductility and the strength–ductility trade-off in NC metals. The speculation that there exists a most brittle grain size for NC metals is confirmed. It is also found that the ductility of NC metals is governed by the GB damage and the ability of intragranular dislocation storage at high GB strength. Moreover, it is shown that the failure tensile strain for cube-textured NC copper at a certain grain size could be more than twice the failure tensile strain for untextured one at high GB strength.

Effect of the Initial Grain Size on Laser Beam Weldability for High-Entropy Alloys

This study investigated the effect of the initial grain size on the laser beam weldability of CoCrFeMnNi high-entropy alloys (HEAs). Cold-rolled, annealed, and cast HEAs with different initial grain sizes exhibited clear differences in weldability. The cold-rolled, annealed, and cast HEAs exhibited grain sizes of 1.5, 8.1, and 1.1 mm, respectively. The grain size of the weld metal (WM) in cold-rolled/annealed HEAs was coarser than that of the base metal (BM), whereas the grain size of the WM in the cast HEA was finer than that of the BM. Shrinkage voids were present in the central region of all laser WMs. The cold-rolled and annealed HEA exhibited a tensile strength greater than 600 MPa owing to the grain size of the coarse WM and the presence of shrinkage voids; however, tensile fracture occurred in the central region of the WM. However, because the grain size of the cast HEA BM was finer than that of the WM, the tensile fracture occurred in the BM, and it had the same tensile properties as the BM. Therefore, the laser weldability of the HEA depended on the initial grain size, and the grain refinement of the WM was essential for improving the weldability.

Schmid factor crack propagation and tracking crystallographic texture markers of microstructural condition in direct energy deposition additive manufacturing of Ti-6Al-4V

Metallic additive manufacturing (AM) provides a customizable and tailorable manufacturing process for new engineering designs and technologies. The greatest challenge currently facing metallic AM is maintaining control of microstructural evolution during solidification and any solid state phase transformations during the build process. Ti-6Al-4V has been extensively surveyed in this regard, with the potential solid state and solidification microstructures explored at length. This work evaluates the applicability of previously determined crystallographic markers of microstructural condition observed in electron beam melting powder bed fusion (PBF-EB) builds of Ti-6Al-4V in a directed energy deposition (DED) build process. The aim of this effort is to elucidate whether or not these specific crystallographic textures are useful tools for indicating microstructural conditions in AM variants beyond PBF-EB. Parent β -Ti grain size was determined to be directly related to α -Ti textures in the DED build process, and the solid state microstructural condition could be inferred from the intensity of specific α -Ti orientations. Qualitative trends on the as-solidified β -Ti grain size were also determined to be related to the presence of a fiber texture, and proposed as a marker for as-solidified grain size in any cubic metal melted by AM. Analysis of the DED Ti-6Al-4V build also demonstrated a near complete fracture of the build volume, suspected to originate from accumulated thermal stresses in the solid state. Crack propagation was found to only appreciably occur in regions of slow cooling with large α + β colonies. Schmid factors for the basal and prismatic α -Ti systems explained the observed crack pathway, including slower bifurcation in colonies with lower Schmid factors of both slip systems. Colony morphologies and localized equiaxed β -Ti solidification were also found to originate from build pauses during production and uneven heating of the build edges during deposition. Tailoring of DED Ti-6Al-4V microstructures with the insight gained here is proposed, along with cautionary insight on preventing unplanned build pauses to maintain an informed and controlled thermal environment for microstructural control.