Complex Microstructural Changes Research Articles

Post-localized blast experimental investigation of mechanical properties and microstructural evolutions in austenitic stainless steel 316L

Mechanical loading causes material deformation, resulting in changes in mechanical properties due to microstructural alterations such as the multiplication of dislocations and evolution of grain morphology. Blast loading, a condition where materials deform at high strain rates, results in significant plastic deformation. This rapid deformation induces intense mechanical stresses, causing complex microstructural changes that influence the mechanical behavior and performance of the materials. Consequently, designing structures to withstand blast loading requires understanding the relationship between microstructure and property evolution. As the primary objective of this study, post-localized blast experiments have been conducted to elucidate the variability in microstructural response of Austenitic stainless steel (ASS) 316 L, characterized by its face-centered cubic crystal structure. Localized blast loads were applied to square test plates, 2 mm thick, with a circular exposed area of 106 mm in diameter. Quantitative mechanical property data from key zones within the deformed dome were determined through using a novel micro-tensile testing approach and nanoindentation tests. Electron backscatter diffraction (EBSD) in scanning electron microscopy (SEM) technique was employed to characterize the microstructural changes in the selected samples. The results revealed that blast loading induced complex mechanical and microstructural changes in ASS 316 L, including enhanced material strength, reduced ductility, and significant alterations in grain orientation and misorientation distributions. The materials underwent significant strain hardening due to the increased stress and deformation, resulting in a more resistant to plastic deformation and the greatest internal strain accumulations. Texture analysis underscored the influence of deformation geometry, with Goss and Copper emerging as predominant texture components.

Effect of friction-stir processing and subsequent aging treatment on microstructure and service properties of Cu-Cr-Zr alloy

The effect of friction-stir processing (FSP) and the subsequent aging treatment on the microstructure, electrical conductivity, and mechanical properties of a Cu-0.3%Cr-0.5%Zr alloy was studied. FSP promoted complex microstructural changes, including significant grain refinement and dissolution of secondary particles within the stir zone and particle coarsening within the heat-affected zone. The particle phenomena resulted in the essential material softening and degradation of electrical conductivity. The subsequent aging treatment provided particle reprecipitation within the stir zone and thus essentially recovered material properties in this area. In the heat-affected zone, however, the recovery effect was less pronounced, thus leading to the characteristic W-shaped profiles of microhardness and electrical conductivity. This result was attributed to the insufficient degree of supersaturation of the solid solution in this microstructural region, which, in turn, promoted the relatively slow precipitation kinetics.

Whole cervix imaging of collagen, muscle, and cellularity in term and preterm pregnancy

Cervical softening and dilation are critical for the successful term delivery of a fetus, with premature changes associated with preterm birth. Traditional clinical measures like transvaginal ultrasound and Bishop scores fall short in predicting preterm births and elucidating the cervix’s complex microstructural changes. Here, we introduce a magnetic resonance diffusion basis spectrum imaging (DBSI) technique for non-invasive, comprehensive imaging of cervical cellularity, collagen, and muscle fibers. This method is validated through ex vivo DBSI and histological analyses of specimens from total hysterectomies. Subsequently, retrospective in vivo DBSI analysis at 32 weeks of gestation in ten term deliveries and seven preterm deliveries with inflammation-related conditions shows distinct microstructural differences between the groups, alongside significant correlations with delivery timing. These results highlight DBSI’s potential to improve understanding of premature cervical remodeling and aid in the evaluation of therapeutic interventions for at-risk pregnancies. Future studies will further assess DBSI’s clinical applicability.

Laser-based resonant ultrasound spectroscopy for monitoring secondary phases in metastable Ti-alloys: From growth kinetics to high-throughput characterization

Metastable beta-Ti alloys undergo complex microstructural changes when annealed for extended times (hours, days, weeks) at temperatures below beta-transus. Contact-less RUS turns out to be a perfect tool for monitoring these processes, as well as for analyzing the properties of the alloys after the heat treatment. In the talk, we will illustrate this ability with three examples of recent advancements in this field. In particular, we will show that RUS is capable of analyzing (i) growth kinetics [1], from fast non-equilibrium phenomena to extremely slow processes; (ii) cubic symmetry conservation in single crystals with particles of various secondary phases [2]; and (iii) phase composition-elasticity relationships in series of oligocrystalline samples [3]. [1] Nejezchlebová et al. Elastic constants of β- Ti15Mo (2019) J Alloys Compounds, 792, pp. 960–967. [2] Olejňák et al. An ultrasound-based evaluation of cubic symmetry preservation and homogeneity in elastic behavior of β+ω and β+α Ti-alloys (2023) Materials and Design, 236, art. no. 112474. [3] Preisler et al., High-throughput characterization of elastic moduli of Ti-Nb-Zr-O biomedical alloys fabricated by field-assisted sintering technique (2023) J Alloys Compounds, 932, art. no. 167656.

Intelligent Online Sensing of Defects Evolution in Metallic Materials during Plastic Deformation

Metallic plastic deformation involves complex microstructural changes and defect evolution, posing challenges in predicting and controlling the quality and performance of formed parts. Therefore, a pressing demand exists for a proficient online defect‐sensing system to monitor defects evolution continuously within components during plastic deformation in real time. This article proposes an intelligent online sensing approach for detecting defects in metallic plastic forming based on acoustic emission (AE) and machine learning. A comparative analysis is conducted on AE amplitude signals, stress–strain curves, and defect evolution during the tensile process of TA15 titanium alloy specimens under different stress states. It is found that the defect formation process can be divided into four stages based on the AE amplitude signals. A convolutional neural network model for intelligent defect sensing is established. It leverages transfer learning and is grounded in the relationship between AE signals and the evolution of internal defects. The prediction accuracy using different pretrained models is investigated and compared. It is discerned that utilizing GoogleNet as the pretrained model offers the swiftest training pace with a prediction accuracy of 97.57%. This approach enables intelligent online sensing of internal defect evolution in metal plastic deformation processes.

Pore Evolution in Cell Walls of Food Tissue during Microwave-Assisted Drying: An In-Depth Investigation.

Microwave (MW) heating is a unique approach that, unlike conduction- and convection-based heating, can provide volumetric heating. Complex microstructural changes in food materials occur because of simultaneous heat and mass transfer during drying, significantly affecting food structure and quality. Food properties, drying methods, and other drying parameters all have an impact on the microstructure of food samples, which in turn affects drying kinetics and food quality. However, no study has been undertaken to investigate the development of nano-micro-pores (NM-pores) on the cell walls and their relationship with the moisture migration mechanism. This study presents a novel investigation of the microstructural changes in food during microwave drying, with a focus on the formation of nano-micro-pores (NM-pores) on cell walls and their impact on moisture transport kinetics. The utilized hot air was maintained at a temperature of 70 °C, whereas microwave (MW) power levels of 100 W, 200 W, 300 W, and 400 W were used in microwave drying. The findings of the study indicate that the development of NM-pores occurs only during intermittent microwave drying (IMCD), while the cell wall of the food samples tends to burn or collapse in continuous microwave drying (CMD) due to the high heat generated. Additionally, no NM-pores were observed in the cell wall during convective drying. During IMCD with microwave power ranging from 100 W to 400 W, a range of pore sizes from 0.1 μm to 8.5 μm were observed. Due to the formation of NM-pores and collapses, MW drying takes around 10-20 times less time than convective drying to remove the same quantity of moisture. The effective moisture diffusivity values were found to be the highest in CMD at 4.70 × 10-07 m2/s and the lowest in CD at 2.43 × 10-09 m2/s. IMCD showed a moderate diffusivity of 2.45 × 10-08 m2/s. This study investigates the formation of NM-pores on cell walls during microwave drying and their impact on moisture transport kinetics and establishes correlations between microstructure modifications and moisture migration pathways.

Diffusion MRI approaches for investigating microstructural complexity in a rat model of traumatic brain injury

Our study explores the potential of conventional and advanced diffusion MRI techniques including diffusion tensor imaging (DTI), and single-shell 3-tissue constrained spherical deconvolution (SS3T-CSD) to investigate complex microstructural changes following severe traumatic brain injury in rats at a chronic phase. Rat brains after sham-operation or lateral fluid percussion (LFP) injury were scanned ex vivo in a 9.4 T scanner. Our region-of-interest-based approach of tensor-, and SS3T-CSD derived fixel-, 3-tissue signal fraction maps were sensitive to changes in both white matter (WM) and grey matter (GM) areas. Tensor-based measures, such as fractional anisotropy (FA) and radial diffusivity (RD), detected more changes in WM and GM areas as compared to fixel-based measures including apparent fiber density (AFD), peak FOD amplitude and primary fiber bundle density, while 3-tissue signal fraction maps revealed distinct changes in WM, GM, and phosphate-buffered saline (PBS) fractions highlighting the complex tissue microstructural alterations post-trauma. Track-weighted imaging demonstrated changes in track morphology including reduced curvature and average pathlength distal from the primary lesion in severe TBI rats. In histological analysis, changes in the diffusion MRI measures could be associated to decreased myelin density, loss of myelinated axons, and increased cellularity, revealing progressive microstructural alterations in these brain areas five months after injury. Overall, this study highlights the use of combined conventional and advanced diffusion MRI measures to obtain more precise insights into the complex tissue microstructural alterations in chronic phase of severe brain injury.

Quantitative Magnetization EXchange MRI Measurement of Liver Fibrosis Model in Rodents.

Quantitative MRI can elucidate the complex microstructural changes in liver disease. The Magnetization EXchange (MEX) method estimates macromolecular fraction, such as collagen, and can potentially aid in this task. MEX sequence, and its derived quantitative macromolecular fraction, should correlate with collagen deposition in rodents liver fibrosis model. Prospective. Sixteen adults Sprague-Dawley rats and 13 adults C57BL/6 strain mice given carbon tetrachloride (CCl4 ) twice weekly for 6 or 8 weeks. A 7 T scanner. MEX sequence (selective suppression and magnetization exchange), spin-echo and gradient-echo scans. Macromolecular fraction (F) and T1 were extracted for each voxel and for livers' regions of interest, additional to calculating the percentage of F > 0.1 pixels in F maps (high-F). Histology included staining with hematoxylin and eosin, picrosirius red and Masson trichrome, and inflammation scoring. Quantitative collagen percentage calculated using automatic spectral-segmentation of the staining. Comparing CCl4 -treated groups and controls using Welch's t-test and paired t-test between different time points. Pearson's correlation used between ROI MEX parameters or high-F fraction, and quantitative histology. F or T1 , and inflammation scores were tested with one-sided t-test. P < 0.05 was deemed significant. Rats: F values were significantly different after 6 weeks of treatment (0.10 ± 0.02) compared to controls (0.080 ± 0.003). After 8 weeks, F significantly increased (0.11 ± 0.02) in treated animals, while controls are not significant (0.0814 ± 0.0008, P=0.079). F correlated with quantitative histology (R=0.87), and T1 was significantly different between inflammation scores (1: 1332 ± 224 msec, 2: 2007 ± 464 msec). Mice: F was significantly higher (0.062 ± 0.006) in treatment group compared to controls (0.042 ± 0.006). F and high-F fraction correlated with quantitative histology (R=0.88; R=0.84). T1 was significantly different between inflammation scores (1:1366 ± 99 msec; 2:1648 ± 45 msec). MEX extracted parameters are sensitive to collagen deposition and inflammation and are correlated with histology results of mouse and rat liver fibrosis model. 1 TECHNICAL EFFICACY: Stage 3.

Kirkendall effect induced ultralow thermal conductivity yields enhanced thermoelectric properties in Mg–Zn–Sb alloys

Thermally induced phase change can modify the microstructure of thermoelectric alloys due to the interdiffusion of atomic species, and also to alter the properties of these materials. Herein, the impact of Mg additive on thermoelectric performance and microstructure of Mg-Zn-Sb thin films is studied. The results show complex microstructural changes upon heating of amorphous Mg-Zn-Sb thin films. The crystallization process of the films leads to the formation of Zn-Sb and Mg-Zn-Sb phases at elevated temperatures. Out-diffusion of Zn during crystallization process results in the formation of Kirkendall voids in Mg-Zn-Sb materials, while no such voids are found in pure Zn-Sb films. The maximum figure of merit (ZT) is found to be ∼1.8 at 584 K for optimized Mg24.3(Zn-Sb)75.7 thin films, which is larger than of other similar thermoelectric materials. Transmission electron microscopy reveal distinct microstructures between the pure and Mg-alloyed Zn-Sb materials. Defects and secondary phase in the alloyed films mainly contribute to effective phonon scattering and lead to very low thermal conductivity (∼0.26 W/m·K at 584 K). Overall, this study shows a way for synthesis of high-performance low-cost Mg-Zn-Sb thermoelectric alloy by microstructure optimization and demonstrates that Kirkendall voids is an effective approach for the enhancement of thermoelectric performance of the materials.

The effect of laser pressure welding parameters on GTD-111 superalloy microstructure

The present study introduces a new joining technique called laser pressure welding (LPW) for welding the GTD-111 superalloy used in gas turbine blades. The results showed that LPW causes complex microstructural changes in the weld metal, base metal, and heat-affected zone (HAZ) by absorbing more laser energy in the weld seam. These changes included elongated grains of rolled base metal, recrystallized grains of the HAZ strain-free equiaxed, columnar grains, and equiaxed of the weld metal elliptical pool. The elongated grains of the base metal and parts of the weld metal columnar grains (around the weld seam) that were solid-pressed in the rolling state had lower angle boundaries and stronger textures. It was also found that if the rolling pressure and heat input are applied simultaneously at the maximum state, it has a significant effect on reducing the porosity of the weld metal. This was more important in terms of higher pressure than more heat input.

Influence of secondary-pass laser treatment on retained ferrite and martensite in 44MnSiVS6 microalloyed steel

Overlapping regions of laser surface treatment are necessary features when processing large surface areas or cylindrical specimens. However, complex microstructural changes that appear in the regions with multiple heat treatment can affect their mechanical properties. Therefore, this study focuses on examining thermal cycle characteristics and resulting microstructures, particularly martensite and retained ferrite structures, to better understand the correlation between experienced thermal cycles and resulting microstructures. Laser surface hardening experiments on 44MnSiVS6 microalloyed steels together with thermal diffusion simulations were conducted to relate microstructures after the secondary pass of the laser treatment to the local thermal cycles experienced during the process. The amount of retained ferrite was calculated and compared to the respective thermal cycle characteristics. Regions which experienced thermal cycles below Ac3 temperature showed microstructures similar to those after tempering. The sizes of retained ferrite structures were found to decrease as the total holding time increases regardless of how the holding time is distributed in multiple laser treatments. However, the size of retained ferrite structures were constant in the region where tempering effect occurred. This shows that the amount of retained ferrite can be tailored by modifying the experienced total holding time and a reduction of retained ferrite structure happens only if the secondary thermal cycle is above Ac3 temperature.

Microstructural evolution during multiple scans in laser polishing of Ti6Al4V

Consecutive thermal cycles during laser polishing lead the complex microstructural changes. It is more difficult for modeling microstructural evolution in multiple thermal cycles compared to the single thermal cycle of heat treatment. In the present work, a thermo-microstructural model is established to investigate the temperature history and microstructural evolution during multiple scans in laser polishing of Ti6Al4V (TC4). The temperature history of the present model is validated the temperature data recorded by the thermal camera. The phase transformation involved α phase and β phase, martensitic transformation and decomposition, as well as the reservation of β phase is considered in the microstructural model. The numerical results show that the non-uniform phase distribution is attributed to the reservation of β phase and the multiple thermal cycles.

Spatiotemporal changes in diffusivity and anisotropy in fetal brain tractography.

Population averaged diffusion atlases can be utilized to characterize complex microstructural changes with less bias than data from individual subjects. In this study, a fetal diffusion tensor imaging (DTI) atlas was used to investigate tract‐based changes in anisotropy and diffusivity in vivo from 23 to 38 weeks of gestational age (GA). Healthy pregnant volunteers with typically developing fetuses were imaged at 3 T. Acquisition included structural images processed with a super‐resolution algorithm and DTI images processed with a motion‐tracked slice‐to‐volume registration algorithm. The DTI from individual subjects were used to generate 16 templates, each specific to a week of GA; this was accomplished by means of a tensor‐to‐tensor diffeomorphic deformable registration method integrated with kernel regression in age. Deterministic tractography was performed to outline the forceps major, forceps minor, bilateral corticospinal tracts (CST), bilateral inferior fronto‐occipital fasciculus (IFOF), bilateral inferior longitudinal fasciculus (ILF), and bilateral uncinate fasciculus (UF). The mean fractional anisotropy (FA) and mean diffusivity (MD) was recorded for all tracts. For a subset of tracts (forceps major, CST, and IFOF) we manually divided the tractograms into anatomy conforming segments to evaluate within‐tract changes. We found tract‐specific, nonlinear, age related changes in FA and MD. Early in gestation, these trends appear to be dominated by cytoarchitectonic changes in the transient white matter fetal zones while later in gestation, trends conforming to the progression of myelination were observed. We also observed significant (local) heterogeneity in within‐tract developmental trajectories for the CST, IFOF, and forceps major.

Softening mechanisms in ultrasonic treatment of deformed austenitic stainless steel

The effect of ultrasonic treatment on the microstructural evolution and the related softening process in tensile pre-deformed 316 stainless steel was studied by means of electron backscatter diffraction method, optical microscopy, and microhardness measurement. It was observed that different levels of ultrasonic energy induced complex microstructural changes in the treated samples. A large decrease in twin boundaries was observed, which is an indication of the de-twinning process under ultrasonic treatment. A new mechanism for the de-twinning process under oscillatory stress of ultrasonic vibration was proposed. It was shown that de-twinning under ultrasonic treatment led to dislocation production from twin boundaries. Inverse pole figures investigation revealed strong grain rotation following ultrasonic treatment in tensile pre-deformed samples. Subgrain formation in the ultrasonic treated austenitic stainless steel samples indicated that considerable ultrasonic energy was induced by the ultrasonic vibration, which provided the activation energy needed for dislocation climb and cross-slip. The ultrasonic induced subgrain formation, dislocation annihilation, and de-twinning, which resulted in a decrease of the microhardness in the samples, can be considered as possible mechanisms for the acoustic softening in the austenitic stainless steels.

Outstanding mechanical properties of ultrafine-grained Al7075 alloys by high-pressure torsion

High frictional die and continuous rotation during high-pressure torsion provide not only a large shear strain but also a large amount of frictional heat that facilitates the generation of complex microstructural changes, including grain refinement, dynamic recovery, and solute migration. Since metallic alloys with low melting temperatures are sensitive to heat energy, the mechanical properties and microstructural evolution of high-pressure torsion-processed aluminum 7075 alloys are investigated in this study. The large shear strain resulting from high-pressure torsion induces both grain refinement and dislocation cell formation, leading to strength enhancement and ductility degradation of the alloy. The deformation and frictional heat become a driving force for solute migration, including brittle intermetallic compound dissolution and nano-sized precipitation generation in the matrix. These solute migration activities contribute toward enhancing both the strength and ductility by inducing precipitation hardening and dissolution of the brittle phase simultaneously. Consequently, both the strength and ductility of the high-pressure torsion-processed aluminum 7075 alloy become larger than that of the initial state. This result shows that the microstructural changes of the severe plastic deformation-processed low-melting-temperature metallic alloys induce a significant mechanical property enhancement of nanocrystalline materials.

Mechanical and electrical properties of Cu-Steel bimetallic porous composite with a double-helix entangled structure

Cu-steel bimetallic porous composite structures can be used as lightweight, damping, and electro-conductive elements in critical environments where traditional single materials become ineffective. In the present work, a novel Cu-steel bimetallic porous composite with a double-helix entangled structure was developed. The mechanical properties (static stiffness, loss factor, and tangent modulus) of the as-synthesized composite were characterized by compressive tests, and its electrical sensitivity to compressive force was examined by mechanical–electrical coupling tests. The effect of the copper/steel weight ratio on mechanical and electrical performances was analyzed in detail. It is found that the Cu-steel bimetallic porous composite with a relatively high weight ratio has a larger average loss factor and lower stiffness than that with a low weight ratio. The structural characteristics and complex microstructural changes of the deformed specimen allow the tangent modulus and stiffness to exhibit a non-proportional relationship with the weight ratio over a range of displacement. The resistance-force curves exhibit an obvious nonlinearity and degradation due to the contact between internal bimetallic wires. The resistance-stiffness history reveals that the mitigation of electrical conductivity continued with the enlargement of stiffness and weight ratio.

Investigation of the reduction roasting of saprolite ores in the Caron process: microstructure evolution and phase transformations

ABSTRACT Fundamental studies have been undertaken to determine the microstructural and phase transformations occurring during the reduction roasting of saprolite ores. Laboratory studies have been undertaken to simulate the conditions occurring during the reduction roast step of the Caron Process. Selected serpentine samples have been treated at temperatures between 500°C and 800°C in H2/N2 gas mixtures, and leaching tests on the reduced samples have been undertaken. Phase and microstructural changes have been characterised using X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) techniques. A series of complex physical, microstructure and phase changes has been shown to occur during reduction roasting involving: (i) the dehydration of serpentine, (ii) the formation of a high-silica amorphous phase, (iii) the formation of Ni-Fe nanoparticles, and (iv) the nucleation, growth and recrystallisation of the forsterite (olivine) phase. The principal mechanism of removal of nickel from the reduced ore has been shown to occur through the selective leaching of the Ni-Fe alloy nano-particles from the surfaces in the product oxide.

Micro-structural effects of irradiation temperature and helium content in neutron irradiated B-alloyed Eurofer97-1 steel

The micro-structural effects of different neutron irradiation temperatures and helium contents, for 16 dpa dose, have been investigated by means of small-angle neutron scattering (SANS) in B-alloyed ferritic/martensitic steel Eurofer97-1 (0.12 C, 9 Cr, 0.2 V, 1.08 W wt%, B concentrations up to 1000 ppm); due to B transmutations, fusion relevant He/dpa values are expected to be produced under neutron irradiation. SANS measurements have been carried out on a sample irradiated at 350 °C, with estimated helium content of 5600 appm, and compared to previous SANS results, obtained on two other irradiated samples of this same B-alloyed steel. These new measurements confirm that for such high helium contents the SANS cross-section increases in order of magnitude and the magnetic SANS component is strongly reduced, compared to lower helium content (400 appm). Such effects are attributed to increase in helium bubbles density and to the presence of micro-cavities, produced after dissolution of large B-carbides. The SANS data analysis procedure has been improved, also thanks to the additional information provided by the new measurements, and more accurate helium bubble size distributions have been obtained for all the investigated samples. For 5600 appm helium content, bubble volume fractions are found of 0.025 for the sample irradiated at 350 °C and of 0.041 for the previously investigated sample irradiated at 400 °C, significantly increasing with the irradiation temperature. These values are approximately one order of magnitude larger than the value of 0.003 previously found for the sample with 400 appm helium. The size distributions are compared with electron microscopy observations of these same samples. It appears that the occurrence of complex micro-structural changes in irradiated Eurofer97-1 steel should be taken in due account when considering its application under high He/dpa ratio values.

Non-destructive investigation of cellular level moisture distribution and morphological changes during drying of a plant-based food material

This study investigates the complex microstructural changes and cell-level water transportation in plant-based food materials during drying, using X-ray micro-computed tomography (X-ray μCT). The investigations were performed on apple tissue to uncover the cellular level moisture distribution and the structural changes during convective drying at 50 °C, 60 °C, and 70 °C. Image analysis revealed that significant changes occurred in moisture content, and cell and pore size distribution with drying time and temperature. The moisture content determined using the X-ray μCT images was compared with that determined by the electronic moisture analyser (EMA) and good agreement was found. The results show a strong relationship between drying temperature, pore formation and deformation of the food material. At high drying temperature, the pore formation increased, which led to reduced shrinkage of the food material. The porosity of a sample of dried apple increased by 35% as drying temperature increased from 50 °C to 70 °C. However, a significant amount of cell rupture was observed during drying at the higher temperature. The cellular level moisture distribution profile confirmed that a traceable amount of water was still present in the centre cells of the tissue although the sample was deemed dried from the bulk moisture analysis. The findings of this study substantially enhance our understanding of instantaneous cellular level moisture distribution in a food sample over the time of drying.

Mapping orbitofrontal-limbic maturation in non-human primates: A longitudinal magnetic resonance imaging study

Brain development involves spatiotemporally complex microstructural changes. A number of neuropsychiatric disorders are linked to the neural processes of development and aging. Thus, it is important to understanding the typical developmental patterns of various brain structures, which will help to define critical periods of vulnerability for neural maturation, as well as anatomical mechanisms of brain structure-related neuropathology. In this study, we used magnetic resonance imaging to assess development of the orbitofrontal cortex, cingulate cortex, amygdala, and hippocampus in a non-human primate species, the common marmoset (Callithrix jacchus). We collected a total of 114 T2-weighted and 91 diffusion-weighted scans from 23 animals from infancy to early adulthood. Quantitative and qualitative evaluation of age-related brain growth patterns showed non-linear structural developmental changes in all measured brain regions, consistent with reported human data. Overall, robust volumetric growth was observed from 1 to 3 months of age (from infancy to the early juvenile period). This rapid brain growth was associated with the largest decrease in mean, axial, and radial diffusivities of diffusion tensor imaging in all brain regions, suggesting an increase in the number and size of cells, dendrites, and spines during this period. After this developmental period, the volume of various brain regions steadily increased until adolescence (7–13 months of age, depending on the region). Further, structural connectivity derived from tractography data in various brain regions continuously changed from infancy to adolescence, suggesting that the increase in brain volume was related to continued axonal myelination during adolescence. Thereafter, the volume of the cortical regions decreased considerably, while there was no change in subcortical regions. Familial factors, rather than sex, contributed the development of the front-limbic brain regions. Overall, this study provides further data on the factors and timing important for normal brain development, and suggest that the common marmoset is a useful animal model for human neural development.