In the present study, osseointegration and bone healing in the two different kinds of interference screws, namely the additive manufactured Ti6Al4V with chemical surface modification (AMD) screw and the commercial control screw, were investigated using X-ray imaging techniques of transmission X-ray microscopy (TXM), projection X ray Microscope (PXM), and X-ray fluorescence (XRF) mapping. TXM provided ultramicrostructural tomography with sharp grayscale contrast at a spatial resolution of 60 nm, enabling clear visualization of individual bone components. PXM captures large-scale three-dimensional (3D) internal morphological structure with mu m-scale resolution and mm-scale field of view, bridging submicroscale and microscale observations. XRF mapping reveals elemental distributions at the bone-screw interface with a spatial resolution of 100 nm, correlating structural features with their chemical composition. These non-destructive techniques demonstrated enhanced bone growth and rich surface osseointegration in the porous AMD screw compared to the control screw, consistent with traditional histology. XRF maps confirmed Ca-rich and P-rich mineral deposition within the AMD screw, in contrast to Fe-rich callus formation at the control screw interface. This study establishes that multiscale X-ray imaging is not only a promising alternative but also a critical tool for comprehensively evaluating the ultramicrostructural mechanisms of bone integration in next-generation additive manufactured orthopedic implants.

Abstract Tribocorrosion-driven wear and stress shielding remain critical challenges limiting the service life of Ti-6Al-4V implants. To address this, nanosilica coatings with PMMA-derived porosity were deposited onto selectively laser-melted Ti-6Al-4V substrates. Composed of 90% silica nanoparticles and 10% PMMA, the coatings increased hardness by 73% and reduced elastic modulus by 26%, collectively improving load transfer and minimising stress shielding. Tribocorrosion testing further demonstrated a 90% reduction in wear alongside significant suppression of toxic aluminium ion release. This enhanced performance is attributed to the formation of a protective Ca-P rich tribofilm on the coated surfaces. Advanced characterisation techniques such as FESEM with EDS mappings, XRD, and XPS were employed to elucidate the underlying mechanisms for the observed reduction in wear and corrosion.

To accomplish the intense desire of high-strength materials for enhanced energy-efficiency, recent research applies a combined strategy of additive-manufacturing and precipitation-strengthening in high entropy alloys. In a context, Al0.2Co1.5CrFeNi1.5Ti0.3 nanoprecipitation-strengthened system was developed, demonstrating very convincing strength and toughness. Moreover, additive-manufacturing facilitated additional strength by well-decorated cell-boundaries with blocky L21 precipitates and homogeneously distributed L12 precipitates. However, fatigue research of this alloy remained unexplored despite being the main precursor for structural applications. In this study low-cycle fatigue behavior of this alloy in both as-built and precipitation-strengthened (aged) conditions has been explored, combined with in-situ neutron diffraction investigation. Findings revealed a substantial cyclic-stress profile and a notable fatigue-life below +/- 0.50% strain-amplitude, exceeding 105 cycles at +/- 0.30% strain-amplitude. These demonstrate the potential to carry higher payloads with marked engineering-reliability. Residual-stress estimation revealed strain-compatibility between the matrix and L12 precipitate, indicating a crack-initiation immune interface. A comparative examination of dislocation character revealed shifting towards pure edge-character in aged alloy indicates precipitates promoted planar-slip during deformation.

Liquid hydrogen storage materials are exposed to extreme environments characterized by temperature below 20 K and hydrogen-rich conditions. Additionally, a comprehensive investigation of the mechanical behavior and hydrogen embrittlement of welded materials is essential for their reliable application as structural components in liquid hydrogen systems. Generally, hydrogen embrittlement often occurs at room temperature in metals, while it tends to diminish as the temperature decreases due to the lower hydrogen diffusivity at cryogenic temperatures. However, one overlooked aspect is that discontinuous serrated deformation, triggered by dislocation avalanches, can induce localized heating even at ultra-cryogenic temperatures. This localized thermal rise may reactivate hydrogen diffusion and promote its accumulation, thereby enhancing the susceptibility to hydrogen embrittlement. A key finding of this study is that a transgranular fracture occurs in both the base metal and heat-affected zone under hydrogen embrittlement conditions at 15 K, primarily due to martensitic phase transformation and hydrogen accumulation at the planar slip band. However, in welded metal with a heterogeneous microstructure, crack propagation tends to occur preferentially along ferrite regions, which are particularly vulnerable to hydrogen embrittlement and cryogenic-induced brittleness. This study aims to reshape the conventional understanding of hydrogen embrittlement at cryogenic environments and provide guidance for enhancing the mechanical reliability of metallic alloys in liquid hydrogen environments.

The current study investigates the role of In on the compressive yield strength of a Sn-0.7 wt. σ_ss) . For an intermediate In alloying concentration of 3 at. (σ_Or ) mechanism owing to the presence of secondary-phase Cu6Sn5 is observed along with solid solution strengthening. For higher In content of 5 at.

Cold rotary-swaging was applied to the metastable β-phase Ti-12Mo-6Zr-2Fe (TMZF) alloy to achieve material with high strength parameters without compromising its low elastic modulus. The process also introduced significant location-dependent property gradient, resulting in difference in the hardness of the outer region by 28.7% compared to the interior region. The increased hardness values at the surface result from a combined contribution of dominant dislocation accumulation, enhanced crystallographic texture, and pronounced subgrain boundaries. The enhanced plastic deformation at the surface together with residual strain accumulation in the interior leads to a beneficial gradient core-shell structure, where the harder shell constrains the softer core. The interplay between the unique characteristics of the TMZF alloy and the deformation mechanisms during cold rotary-swaging demonstrates a practical pathway to tailor desirable spatially distributed mechanical properties for superior fatigue resistance in other advanced alloy systems. Specifically, this work provides quantitative microstructure distribution subjected to rotary swaging.

In the present study, the synergistic effects of scandium (Sc) and zirconium (Zr) additions, as well as the influence of secondary processing (rolling and aging), on the microstructure and hardness of squeeze-cast Al-7Si-0.8Mg alloy were investigated. It was observed that the addition of 0.3 wt.

This work uses powder metallurgy technique to fabricate six-layered aluminum–alumina functionally graded material with 0–50

This study compares the microstructural and mechanical properties of Mg-10Y alloy synthesized via two different processing routes: vacuum die (VD) casting and disintegrated melt deposition (DMD) process. The analysis through scanning electron microscopy (SEM) and 3D X-ray microscopy (XRM) revealed that the alloy processed through DMD exhibited a higher fraction of eutectic Mg24Y5 phase as compared to the alloy processed through VD casting. Although the individual Mg24Y5 phase in both the alloys exhibited a partially divorced eutectic morphology, the divorced degree (D-d) for DMD processed alloy was similar to 60% higher than the D-d of alloy synthesized through VD casting due to the higher cooling rate in the former. Both hardness and yield strength (YS) of the DMD processed alloy was found to be higher than VD processed alloy, which has been predominantly attributed to the significantly smaller grain size in the former (similar to reduction by 83.5%). In addition, ultimate compressive strength (UCS) and UCS/YS were also found to be higher for the DMD processed alloy. The addition of 10 wt% Y was found to significantly improve the ignition temperature as compared to other as-cast Mg alloys and the strength was further improved by using DMD method, giving advantage over VD casting.

The hot deformation behavior of Al0.3Co1.5CrFeNi1.5Ti0.2 high-entropy alloy was studied at temperatures and strain rates varying from 923 to 1373 K and 10(-3) to 1 s(- 1), respectively. A constitutive equation was formulated to characterize material flow within these conditions and predict its behavior under similar or extended conditions. Stress exponent and deformation activation energy were determined to be 4.44 and similar to 490 kJ/mol, respectively, suggesting that the material undergoes high-temperature deformation primarily controlled by dislocation climb. Moreover, at 923 K, the power law breakdown was observed, with no flow softening occurring up to a true strain of 0.5. The processing map identified optimal deformation conditions, achieving highest efficiency (similar to 34 %), at strain rates of 0.03 - 1 s(- 1), and temperatures > 1300 K. Instability domain (strain rate range: 0.01 - 1 s(-1), temperatures: 923-1165 K), was characterized by presence of voids and cracks. Further, transmission electron microscopy study highlighted the dynamic development of L1(2), B2 and sigma phases at different temperatures and identified their correlation with instability domains in the processing map. The predominant deformation mechanisms were identified as dislocation climb and discontinuous dynamic recrystallization (DDRX). Electron back scattered diffraction microstructural investigations confirmed the occurrence of DDRX.

The present failure investigation pertains to the failure of U-bend of the reheater section of an 800 MW supercritical coal fired power plant. The cracks were found on the intrados side and the neutral axis of the U-bend tube at approximately 64° from the center of the bend. The intrados side crack was circumferentially aligned, whereas the neutral axis crack was longitudinally aligned. Microstructural investigation revealed intergranular failure in both types of cracking. SEM–EBSD investigation revealed an extensive amount of strain accumulation near the grain boundaries and triple boundaries, for both the cases. As the nature of stresses was complicated, the Schmid Factor maps were able to help in determining the possible direction of stress wherein the activation of {111}⟨ 101⟩ slip system was considered. Additionally, the presence of metallic filaments, intergranular nature of cracking and premature failure highlights strong evidence of stress relaxation cracking.

This study evaluates the tribological performance of copper (Cu) and silica (SiO2) nanoparticles used individually and in combination as hybrid additives in PAO-4 oil. The 0.5 wt % Cu + 0.5 wt % SiO2 formulation demonstrated superior dispersion stability, favorable rheological properties, and excellent tribological behavior. At room temperature, the hybrid nanolubricant reduced friction and wear by similar to 52% and similar to 45%, respectively, while, at 100 degrees C, reductions improved to similar to 68% and similar to 88%. TOF-SIMS, cross-sectional TEM-EDS, and APT analyses of worn surfaces revealed the formation of hybrid tribofilms, with thicknesses of 300 +/- 31nm at room temperature and 168 +/- 61 nm at 100 degrees C. The enhanced performance is attributed to the synergistic interaction between the additives and temperature-dependent variations in tribofilm composition and formation.

The present study investigates the effect of Mg addition on the aging and tensile behaviour of squeeze cast Al-7Si-(x)Mg alloys (x = 0-0.8 wt. %). The results show that increasing Mg content leads to a significant enhancement in the peak hardness of the alloys, with the maximum hardness of 149 HV observed for the Al-7Si-0.8Mg alloy after aging for 10 h. Additionally, the study reveals that Mg addition delays the aging kinetics, likely due to the interplay between the optimized number density and size of the precipitates, which require longer aging times to reach their optimal size for maximum strengthening. The tensile strength of the alloys increases with higher Mg content, with the peak-aged Al-7Si-0.8Mg alloy achieving a tensile strength of 337 MPa. The increase in hardness and strength with increasing Mg addition is attributed to the higher number of Mg2Si precipitates formed during aging which hinder dislocation movement. The yield strength of all alloys was predicted using the standard strengthening formula, showing that precipitation strengthening contributes the maximum to the overall yield strength for all the alloys, followed by solid solution strengthening. The present study also reveals the presence of both the beta" and the beta precipitates in the peak-aged samples, suggesting a combined strengthening effect from both precipitates.

The stress relaxation test is a transient mechanical examination tool widely employed to investigate material deformation kinetics. This study reports the time-dependent plastic deformation response of additively manufactured (AM) SS316L under different heat treatment conditions. The thermal activation and deformation kinetics of the AM SS316L alloy were analyzed along with microstructural investigations. The stress-time response during relaxation was analyzed using a recently proposed constitutive model, and the dependence of activation volume, strain rate sensitivity and the exhaustion of mobile dislocation density were estimated for different heat treatment conditions. The results demonstrate a significant correlation between the exhaustion of mobile dislocations and cellular structure. Furthermore, potential mechanisms to provide a comprehensive understanding that governs the transient deformation response in AM SS316L alloy are discussed.

The room temperature (RT) and high-temperature (373-573 K) hardness of individual phases of Ti45Ni50Fe5 multiphase intermetallic are evaluated using nanoindentation. The B2 matrix exhibits anomalous behavior whose hardness decreases from RT to 373 K followed by an increase up to 573 K. In contrast, the hardness of the DO24 phase continuously reduces up to 473 K. Molecular dynamics simulation of single crystal compression of B2 matrix shows the presence of 12 < 111 >$\frac{1}{2} \overset{\cdot}{1} 11$ screw partial dislocations at all temperatures whose density increases up to 473 K followed by a decrease at 573 K. It is anticipated that individual screw super partial cross-slips from {110} to {211} plane at the higher temperature, with their core becoming nonplanar. The nonplanar core of these screw partials acts as a dragging point for the motion of dislocation leading to hardness anomaly vis-& agrave;-vis yield strength anomaly. The DO24 phase does not exhibit any anomalous behavior in hardness in the studied temperature range due to the presence of super partial dislocations bounded by super intrinsic stacking faults instead of antiphase boundaries.

This study deals with the development of Ti-Ni-Fe based multi-phase intermetallic having high strength with enhanced ductility and elucidation of their deformation characteristics. The intermetallic exhibited a compressive strain and strength of- 11 % and- 2.1 +/- 0.112 GPa at room temperature (RT), respectively. MD simulation at RT showed a higher dislocation density in the DO24 phase, where most of the dislocations were found to be superpartials 31 (1010) and31 (1100) separated by super intrinsic stacking faults (SISF), which was further corroborated with TEM analysis. It was found that despite its low volume fraction, DO24 phase governed the plastic deformation. Further, hot compression of Ti45Ni50Fe5 exhibited yield strength anomaly (YSA), where yield strength decreased from room temperature to 373 K followed by an increase at 473 K and 573 K. MD simulation of hot compression showed lower dislocation density (-300-551x10- 6 & Aring;- 2 ) for B2 matrix at all temperatures, indicating strength is predominantly governed by it. The dislocation density of B2 matrix was found to increase with temperature up to 373 K followed by a decrease at 473 K and 573 K. This difference in dislocation density has been attributed to the cross-slip of 12 (111) screw partials from {110} plane to {211} plane, resulting in the formation of dislocation lock that led to YSA behavior.

Advanced high strength steels (AHSS) present a promising strength-to-weight ratio for sheet metal forming applications; however, their poor stretch-flangeability, particularly concerning edge cracking, poses a significant challenge. In recent years, interrupted loading through servo press has emerged as a promising approach to enhance formability. While the past literature has unveiled the mechanism of time-dependent plastic deformation and its contribution to interrupted loading, the role of interface friction and its transient effect on stretch-flangeability is not understood. This study investigates non-conventional forming techniques involving interrupted loading during deformation. Two distinct punch motion modes, namely attach-hold (AH) and attach-detach (AD), are systematically examined to evaluate stretch-flangeability. The findings reveal that implementing interrupted loading modes (AH, AD) effectively delays failure, consequently improving stretch-flangeability. Comprehensive failure analysis and subsequent metallurgical characterization elucidate the mechanisms underpinning the enhanced stretch-flangeability. The microstructural mechanisms contributing to improved stretch-flangeability are thoroughly discussed.

Several rare-earth (e.g. Y, Gd, Nd, Ce) additions have been investigated till date in magnesium alloys. However, limited efforts have been made to examine the influence of Erbium (Er) in Mg alloys. This study is designed to unravel the role of Er addition on wear and friction characteristics of Mg-Er alloys. As-cast Mg-Er (0.5-12 wt%) alloys were prepared and tested under dry sliding conditions with varying normal loads (5 N to 100 N) and sliding speeds (0.01 m/s to 0.1 m/s). The results indicated that the addition of Er to Mg significantly improved the overall wear properties of the alloys. At higher Er content, a substantial decrease in severe wear rate region (75 %), while a - 40 % reduction in friction coefficient were observed. The formation of a protective tribo-oxide layer at the contact zone due to the increase in temperature from friction, combined with the strengthening effect of the Er-rich precipitates, contributed to enhanced wear resistance with Er addition. The surface energy of the Mg-12Er alloy was less than that of other Mg-Er alloys (- 50 % reduction), causing reduced adhesion and abrasion wear and thus reducing the overall wear rate. Furthermore, it was observed that higher applied normal loads led to increased wear rates and friction coefficients, whereas with increasing sliding speed, the wear rate was reduced. Major wear mechanisms observed were abrasive, adhesive, plastic deformation, oxidation, and fatigue wear along with delamination.

In this work, the role of Er addition on texture, recrystallization and mechanical properties has been systematically studied in a binary Mg-Er alloy. As-cast Mg-1Er and Mg-5Er (wt. %) alloys were hot-rolled and annealed at 400 degrees C for different durations from 3 min to 60 min. The evolution of microstructure and texture were studied using electron back-scattered diffraction (EBSD), high resolution transmission electron microscopy (HRTEM) and X-Ray diffraction. Recrystallization kinetics were analyzed using combined hardness measurements and JohnsonMehl-Avrami-Kolmogorov (JMAK) model. Additionally, tensile testing was conducted on hot-rolled and recrystallized samples. Er addition significantly influenced the propensity of twinning. It was observed that the addition of Er increased the proportion of contraction twins (CT) and double twins (DT) but lowered the extension twin (ET). Similarly, both as-rolled and recrystallized textures were influenced by Er addition. Increasing Er content reduced basal texture intensity. Quantitative assessment of recrystallization fraction suggested that Er addition lowers the recrystallization kinetics in Mg-Er alloys. The mechanical properties were superior in Mg-5Er alloys in both hot-rolled and annealed samples. Among several factors, the influence of Er addition on deformation mechanisms, solid solution strengthening, and solute drag effect seems to play a dominant role in explaining the results.