IN THIS STUDY, EARTH BLOCKS (EB) AND COMPRESSED EARTH BLOCKS (CEB) ARE FABRICATED AND INVESTIGATED ALONG WITH THE DEVELOPMENT OF A MATHEMATICAL MODEL OF COMPRESSIVE AND TENSILE LOADS. THE INVESTIGATED SPECIMENS ARE MANUFACTURED FROM A MIXTURE OF SOIL, GROUND RECYCLED CONCRETE (GRC) POWDER AND WATER IN WEIGHT FRACTIONS OF 4:1:1. EBS ARE MOLDED AND CEBS ARE OBTAINED BY QUASI-STATIC COMPRESSION IN WET STATE. MATERIAL SAMPLES EXTRACTED FROM THE BLOCKS ARE TESTED IN DRY STATE FOR COMPRESSIVE STRENGTH AND THREE-POINT FLEXURAL STRENGTH ACCORDING TO ASTM STANDARDS. THE RESULTS INDICATE THAT CEB EXHIBITS 130% HIGHER COMPRESSIVE LOAD CAPACITY AND 63% HIGHER TENSILE STRENGTH COMPARED TO EB. FURTHERMORE, THE PROPOSED AND CALIBRATED MATHEMATICAL MODEL IS ABLE TO ADEQUATELY DESCRIBE THE STRENGTH AND DAMAGE BEHAVIOR OF BOTH MATERIALS. FINALLY, MICROSTRUCTURAL/MICROMECHANICAL INTERRELATIONSHIPS WITH THE MODELED MATERIAL RESPONSE ARE ESTABLISHED BASED ON A CHARACTERIZATION OF POSTMORTEM CEB SAMPLES USING EDS ELEMENTAL ANALYSIS AND SEM MICROGRAPHS TECHNIQUES

THE ANISOTROPIC PLASTICITY CONSTANTS OF THE CPB06 CRITERION FOR TI64, PREVIOUSLY IDENTIFIED WITH EXPERIMENTS PERFORMED IN ALL THREE DIMENSIONS, ARE APPLIED HERE TO EVALUATE THE EFFECT OF THE DIRECT AND INVERSE CALIBRATION STRATEGIES OF THE TENSILE-COMPRESSION ASYMMETRY PARAMETER K ON THE PREDICTIVE BEHAVIOR OF LARGE DEFORMATIONS OF THE HEXAGONAL CLOSE-PACKED (HCP) ALLOY. THE DIRECT CALIBRATION STRATEGY IS BASED ON MODEL FITTING WITH EXPERIMENTAL STRAIN HARDENING DATA UP TO THE ONSET OF PLASTIC INSTABILITY. THE INVERSE CALIBRATION STRATEGY REDUCES PREDICTION ERRORS OF THE LOAD-DISPLACEMENT CURVES OF BOTH THE CYLINDRICAL BAR TENSILE AND THE ELLIPTICAL CYLINDER COMPRESSION TESTS. THE RESULTS PROVIDE INTERESTING INSIGHTS INTO THE IDENTIFICATION OF THE LAWS MODELING LARGE DEFORMATIONS OF HCP MATERIALS.

QUENCH AND PARTITION STEELS FIND WIDE USE IN THE AUTOMOTIVE INDUSTRY BECAUSE OF THEIR HIGH CAPABILITY OF ENERGY ABSORPTION. INDUSTRIAL DEMANDS HAVE PROMPTED THE EXPANSION OF THIS RESEARCH FIELD BECAUSE OF THE INFLUENCE THESE MATERIALS HAVE ON COMPONENTS THAT CAN ABSORB HIGH ENERGY OF IMPACT TO REDUCE PASSENGER DAMAGE, FOR EXAMPLE. THE PARTITION PROCESS'S DIFFICULTIES LIE MAINLY IN CONTROLLING THE THERMODYNAMICS AND THE KINETICS OF THE PHASE TRANSFORMATION. BOTH AFFECT ACHIEVING ADEQUATE AUSTENITE RETENTION AND OPTIMAL MECHANICAL PROPERTIES. MANY RESEARCHERS HAVE ATTEMPTED TO INCREASE THESE MATERIALS' ENERGY ABSORPTION EFFICIENCY BY INCORPORATING MICROALLOYING ELEMENTS THAT CONTROL PHASE TRANSFORMATION DURING THE PARTITIONING PROCESS, TYPICALLY DONE IN THREE STEPS. HOWEVER, NO RESEARCH HAS BEEN CARRIED OUT ON THIS TOPIC USING NB AND SI MICROALLOYING ON LOW-CARBON STEELS IN TWO STAGES. THEREFORE, AN ALLOY WAS DESIGNED AND MODELLED WITH MECHANICAL REINFORCEMENT BY PRECIPITATION AND TRANSFORMATION-INDUCED PLASTICITY (TRIP), DOPING THE STEEL WITH NB AND SI IN A TWO-STAGE QUENCHING AND PARTITIONING PROCESS. THEN, STEEL SAMPLES WERE FABRICATED TO VALIDATE THE MODEL. THERE WERE TWO GROUPS OF SAMPLES WITH DIFFERENT DIMENSIONS TO EVALUATE THE SENSITIVITY OF AUSTENITE RETENTION CONCERNING THE SAMPLE THICKNESS. THE MAIN RESULTS SHOWED THAT 10.75% OF RETAINED AUSTENITE ALLOWS AN ENERGY ABSORPTION OF 30.55 GPA% WITH A TWO-STAGE QUENCHING AND PARTITIONING HEAT TREATMENT. SAMPLE THICKNESS INFLUENCES AUSTENITE RETENTION DUE TO DIFFUSION KINETICS DURING THE PARTITIONING PROCESS. FINALLY, VIRTUAL TESTS QUANTIFIED THE UNIT STRAIN ENERGY ABSORPTION OF THE RETAINED AUSTENITE AT 1.9 MJ AT 25 °C.

THE PRESENT WORK UPDATED EMPIRICAL PARAMETER RANGES WITH A HIGH ADJUSTMENT TO THE EXPERIMENTAL RESULTS AS OBTAINED BY THE MEANS OF THE EXPLORATORY DATA ANALYSIS (EDA) METHOD. A NEW HIGH ENTROPY ALLOY WITH FCC STRUCTURE REINFORCED BY PRECIPITATION OF INTERMETALLIC PHASES FABRICATED BY VACUUM-ARGON INDUCTION MELTING WAS DESIGNED AND MODELED. THE MAIN RESULTS SHOWED THAT THE VALENCE ELECTRON CONCENTRATION (VEC) IS THE PREDOM-INANT EMPIRICAL PHASE PREDICTION PARAMETER IN HIGH ENTROPY ALLOYS AND THAT THE LATTICE PACKING FACTOR IS NECESSARY TO DETERMINE THE PRESENCE OF INTERMETALLIC PHASES EFFECTIVELY. PHASE STABILITY RANGES BASED ON VEC ASSOCIATED WITH THE BASE CRYSTAL STRUCTURES AND THE PRESENCE OF INTERMETALLICS CORROBORATED COMPUTATIONALLY BY CALPHAD AND EXPERIMENTALLY WERE REPORTED. THE INTERDENDRITIC ZONE PROVED TO BE A PREFERENTIAL PRECIPITATION ZONE WITH PRE-CIPITATES OF SIGMA, TIC, AND GAMMA' PHASES. THE GAMMA' PHASE SHOWED A SIZE DIFFERENCE BETWEEN THE DENDRITIC AND INTERDENDRITIC ZONE ASSOCIATED WITH DIFFUSIVE TI MECHANISMS. THE NANOSCALE MECHANICAL RESPONSE DETERMINED THAT DISLOCATION CREEP AND REINFORCEMENT IN THE INTERDENDRITIC ZONE ARE PREDOMINANT CREEP MECHANISMS THAT OBTAINED AN EFFECTIVE ENTANGLEMENT OF THE DISLOCATIONS INCREASING THE STRAIN HARDENING COEFFICIENT. THE MECHANICAL RESPONSE OF THE ALLOY OBTAINED IS SUPERIOR TO THE AVERAGE OF THE ALLOYS WITH FCC STRUCTURE. IT MAINTAINS A HIGH DUCTILITY THAT ALLOWS REACHING AN ENERGY ABSORPTION AND DAMAGE TOLERANCE OF 43.56 GPA% SHOWING SEVERE PLASTIC SLIP LINES BEING IN THE RANGE OF USE FOR AEROSPACE APPLICATIONS AND HYDROGEN TANKS.

THE IMPACT OF THE ADDITION OF 0.5 WT% MULTIWALL CARBON NANOTUBES (MWCNT) ON THE QUASI-STATIC TRANSVERSE COMPRESSIVE RESISTANCE AND DAMAGE EVOLUTION OF UNIDIRECTIONAL GLASS FIBER REINFORCED COMPOSITE (FRC) FABRICATED BY RESIN TRANSFER MOLDING IS INVESTIGATED. THE DEGRADATION OF MACROSCOPIC MECHANICAL PROPERTIES SUCH AS ELASTIC MODULUS AND COMPRESSIVE STRENGTH VS. PLASTIC STRAINS ARE CORRELATED WITH CRACK DENSITY AND MICROCRACK PROPAGATION BEHAVIOR INCLUDING ANALYSIS OF FAILURE PHENOMENA SUCH AS INTERFACE DEBONDING, MATRIX CRACKING AND INTERFACE CRACKING. THE EXPERIMENTAL CAMPAIGN INCLUDES COMPRESSION TESTS WITH MONOTONIC AND CYCLIC LOADS ON CUBIC SPECIMENS IN THE OUT-OF-PLANE (0°) AND TRANSVERSE (90°) DIRECTIONS FOR MASTERBATCH MWCNT-BASED AND CNT-FREE GLASS FRC. IN THE MONOTONIC CASE, THE ELASTIC MODULUS AND MAXIMUM COMPRESSIVE STRENGTH INCREASED FOR THE GLASS FRC WITH 0.5 WT% CNTS, PARTICULARLY IN THE TRANSVERSE (0°) DIRECTION BY 11% AND 13%, RESPECTIVELY. UNDER CYCLIC LOADING, THE ELASTIC MODULUS DEGRADATION STAGNATES AT A LOWER PLASTIC DEFORMATION FOR COMPOSITE WITH 0.5 WT% CNTS. IN ADDITION, CNTS REDUCES BY 20% THE CUMULATIVE PLASTIC DEFORMATION IN THE 0° DIRECTION AND ALMOST 30% IN THE 90° DIRECTION. AT THE MICROSCOPIC SCALE, IMAGE ANALYSIS SHOWED THAT THE CNTS IMPROVED THE PROPERTIES OF THE INTERFACE BY DELAYING DECOHESION FAILURE AND REDUCING BY AROUND 30% AND 40% THE COMPUTED CRACK DENSITY IN THE 0° AND 90° LOADING DIRECTION, RESPECTIVELY. IN ADDITION, IMAGE ANALYSIS IN THE OUT-OF-PLANE DIRECTION (0°) SHOWS THAT FIBER-MATRIX DECOHESION IS PREDOMINANT BEFORE CRACK PROPAGATION AT THE INTERLAMINAR LEVEL AND PRIOR TO FINAL FAILURE. BY CONTRAST, AT 90° LOADINGS, NO DECOHESION IS OBSERVED AND CRACK PROPAGATION IS ALMOST PURELY INTERLAMINAR. FINALLY, THE ADDITION OF 0.5% MWCNTS TO THE GLASS FRC INCREASES THE MECHANICAL RESISTANCE OF THE COMPOSITE MATERIAL IN THE TRANSVERSE DIRECTION DEMONSTRATED BY THE DELAYING OF CRACKS DURING THE FAILURE ANALYSIS OF DIFFERENT CYC

THREE-DIMENSIONAL PRINTING HAS EXPERIENCED STEADY GROWTH ACROSS VARIOUS INDUSTRIES, BUT ITS APPLICATION IN THE PRODUCTION OF BIOMEDICAL DEVICES AND COMPONENTS IS HINDERED BY THE LACK OF MATERIALS WITH SUITABLE MECHANICAL PROPERTIES AND CONTROLLED BIOACTIVITY. MOST POLYMERS HAVE LIMITATIONS IN TERMS OF THEIR STRENGTH AND BIOACTIVITY, NECESSITATING THE INCORPORATION OF SPECIAL FEATURES TO OVERCOME THESE SHORTCOMINGS. AMONG THESE POLYMERS ARE POLYLACTIC ACID (PLA) AND POLYPROPYLENE (PP), WHICH ARE HIGHLY REUSABLE MATERIALS. ZEOLITE, A WIDELY AVAILABLE NATURAL MATERIAL, HAS THE POTENTIAL TO ADDRESS THESE BIOACTIVITY AND STRENGTH LIMITATIONS. THEREFORE, THIS STUDY FOCUSES ON THE DEVELOPMENT OF COMPOSITE MATERIALS, SPECIFICALLY PLA + ZEOLITE AND PP + ZEOLITE, DOPED WITH CU NANOPARTICLES. THE GOAL IS TO OBTAIN COMPOSITE MATERIALS CAPABLE OF EFFECTIVE APPLICATION IN THE BIOMEDICAL FIELD THROUGH 3D MANUFACTURING, PROVIDING AN EFFICIENT, COST-EFFECTIVE, AND NON-TOXIC ALTERNATIVE. THE METHODOLOGY EMPLOYED INVOLVED EXTRUSION MANUFACTURING, FOLLOWED BY THE VALIDATION OF ZEOLITE DISPERSION IN PP AND PLA THROUGH OPTICAL MICROSCOPY AND THE ANALYSIS OF ZEOLITE MORPHOLOGY USING SCANNING ELECTRON MICROSCOPY. THE MECHANICAL RESPONSE OF THE MATERIALS WAS DETERMINED THROUGH NANOINDENTATION TESTS AND TENSILE EXPERIMENTS. THE RESULTS OBTAINED REVEALED AN APPROPRIATE DISPERSION OF ZEOLITE IN BOTH POLYMER MATRICES. NANOINDENTATION TESTS HIGHLIGHTED SIGNIFICANT ANISOTROPY AND AN AUXETIC RESPONSE IN ZEOLITE. HOWEVER, VIRTUAL TESTS DEMONSTRATED A HIGH PRECISION BETWEEN SUBMICROMETRIC AND MACROMETRIC SCALES IN THE COMPOSITE MATERIALS. TENSILE TESTS INDICATED A SUBSTANTIAL INCREASE IN THE STIFFNESS OF THE COMPOSITE UPON ZEOLITE INCORPORATION, WITH A 21.48% INCREASE IN THE CASE OF THE PLA MATRIX COMPARED TO PLA WITHOUT ZEOLITE, AND A 19.12% INCREASE IN THE CASE OF PP COMPARED TO PP WITHOUT ZEOLITE. THESE RESULTS HOLD PROMISE FOR THE FABRICATION OF FILAMENTS INTENDED FOR ADDITIVE MANUFACTURING PROC

THE CORROSION AND MECHANICAL RESPONSE PRODUCED BY QUENCHING IN THE WELDED JOINT OF A NEW NB-DOPED STAINLESS STEEL DESIGNED BY THE CALPHAD METHOD AND PRODUCED BY OPEN-ATMOSPHERE CASTING WITH RECYCLED MATERIALS WERE INVESTIGATED TO CONTRIBUTE TO THE CIRCULAR ECONOMY AND TO ESTABLISH DISRUPTIVE MANUFACTURING CRITERIA BASED ON METALLURGICAL PRINCIPLES. THE STEEL WAS INITIALLY SUBJECTED TO SOLUBILIZATION HEAT TREATMENT AND PARTIAL SOLUBILIZATION TREATMENT AT 1090 °C TO OBTAIN AN APPROPRIATE ?/? BALANCE AND CARBIDE SOLUBILIZATION. IT WAS THEN WELDED BY THE SMAW PROCESS, QUENCHED, AND TEMPERED AT THREE DIFFERENT COOLING RATES. AS A RESULT, A GOOD FIT BETWEEN THE PHASES PREDICTED BY THE CALPHAD METHOD AND THOSE OBSERVED BY X-RAY DIFFRACTION AND SCANNING ELECTRON MICROSCOPY WERE OBTAINED, WITH MINOR DIFFERENCES ATTRIBUTABLE TO THE PRECIPITATION AND DIFFUSION KINETICS REQUIRED FOR DISSOLUTION OR NUCLEATION AND GROWTH OF THE PHASES IN THE SYSTEM. THE FORCED AIR QUENCHING MECHANISM WAS IDENTIFIED AS PROVIDING AN ?/? PHASE EQUILIBRIUM EQUIVALENT TO 62/38 AS THE MOST EFFECTIVE QUENCHING METHOD FOR ACHIEVING THE OPTIMUM MECHANICAL AND CORROSION RESPONSE, EVEN WITH THE POST-WELD ? PHASE AND SHOWING SUPERIOR RESULTS TO THOSE OF THE BASE METAL. THE OUTSTANDING MECHANICAL AND CORROSION RESPONSES RESULTED FROM A PROPER BALANCE OF THE PRIMARY PHASES IN THE DUPLEX STEEL WITH A PRECIPITATION-STRENGTHENING MECHANISM. THE DAMAGE TOLERANCE OBTAINED BY FORCED AIR QUENCHING WAS SUPERIOR TO THAT OBTAINED BY WATER AND AIR QUENCHING, WITH A PSE OF 24.71 GPA% POST-WELDING.

ADDITIVE MANUFACTURING OF COMPOSITE MATERIALS IS A PROMISING TECHNOLOGY. IT COULD SOLVE ONE OF THE MOST CRITICAL DRAWBACKS OF 3D-PRINTED FIBER-REINFORCED THERMOPLASTICS: THEIR LOW OUT-OF-PLANE MECHANICAL PROPERTIES. DUE TO THIS FACTOR, IT IS STILL UNKNOWN HOW MOST DESIGN AND MANUFACTURING PARAMETERS AFFECT THE OUT-OF-PLANE PROPERTIES OF COMPOSITE MATERIALS. AS A SOLUTION, THIS PAPER PROPOSES AN EXPERIMENTAL METHODOLOGY TO CHARACTERIZE OUT-OF-PLANE PRINTED COMPOSITE MATERIALS. FOR THIS PURPOSE, EXISTING STANDARDS FOR TRADITIONALLY FABRICATED COMPOSITES ARE ADAPTED, INVESTIGATED, AND VALIDATED FOR 3D-PRINTED LAMINATES REINFORCED WITH LONG FIBERS USING THE FUSED FILAMENT FABRICATION TECHNIQUE. CONSEQUENTLY, THE METHODOLOGY IS EMPLOYED TO STUDY THE IMPACT OF STACKING SEQUENCE AND HEAT TREATMENT CONDITIONS ON THE COMPOSITES? OUT-OF-PLANE MECHANICAL PROPERTIES. THE MAIN RESULTS SHOWED THAT INCREASING THE THICKNESS BETWEEN STACKING LAYERS INCREASES THE MECHANICAL RESPONSE DUE TO REDUCING THE NUMBER OF FIBER/MATRIX INTERFACES AND, CONSEQUENTLY, THE REDUCTION OF POROSITY. COMPARED TO THE INITIAL SAMPLE, A HEAT TREATMENT AT 175 °C FOR 6 H INCREASED THE INTERFACIAL STRENGTH BY 101.09% AND REDUCED THE POROSITY IN THE FIBER PRODUCED BY THE ADDITIVE MANUFACTURING PROCESS BY 72%

THIS WORK AIMS TO EVALUATE THE CRITICAL BUCKLING LOAD OF PANELS MADE OF CROSS-LAMINATED TIMBER, CONSIDERING FINITE ELEMENT SIMULATIONS AND DIFFERENT ANALYTICAL METHODS OF CALCULATING THE EFFECTIVE BENDING AND SHEAR STIFFNESS. IN ADDITION, THE EFFECT OF OPENINGS, PRE-CRACKS, AND ADHESIVE STRENGTH ON THE CRITICAL BUCKLING LOAD IS ANALYZED. RESULTS INDICATE THAT THE APPROACH WITH THIN EXTERNAL FACES IS BOTH SIMPLER AND MORE EFFECTIVE. WHEN ESTIMATING THE BENDING AND SHEAR STIFFNESS, THE METHODS THAT SHOW THE LEAST DIFFERENCE ARE THE ?-METHOD AND THE SHEAR ANALOGY METHOD, WITH THE FIRST OF THEM BEING MORE CONSERVATIVE. THE CORRECTED TIMOSHENKO METHOD TENDS TO OVERESTIMATE THE CRITICAL LOAD. MOREOVER, USING COHESIVE ZONE MODELS EMBEDDED IN FINITE ELEMENT SIMULATIONS, THE CRITICAL LOAD IS REDUCED BY AN AVERAGE OF 10% DUE TO THE STIFFNESS OF THE ADHESIVE. FURTHERMORE, WHEN PANELS HAVE ADHESIVE-FREE EDGES, THE CRITICAL LOAD CAN BE REDUCED BY MORE THAN 50%.

THE OBJECTIVE OF THIS PAPER IS TO DETERMINE THE IMPACT OF DENSITY FRACTION ON THE MECHANICAL PROPERTIES OF 3D PRINTED THERMOPLASTIC MATERIALS TO MAXIMIZE THE MECHANICAL STRENGTH OF PARTS THROUGH A COMBINATION OF TOPOLOGY OPTIMIZATION AND TAILORED DENSITY FRACTION. THE RESULTS OBTAINED REVEAL A SIGNIFICANT FINDING OF THE APPLICABILITY OF THE STRATEGY FOR IMPROVING ADDITIVE MANUFACTURING PROCESSES, DESIGN AUTOMATION, AND MANUFACTURING OF HIGH-STRENGTH COMPONENTS. THE EFFECT OF INFILL DENSITY AND PRINT ORIENTATION ON THE MECHANICAL PROPERTIES OF PLA-BASED 3D-PRINTED PARTS ARE QUANTIFIED BY ULTIMATE STRENGTH AND YOUNG?S MODULUS IN TWO MATERIAL ORIENTATIONS (IN THE PRINTING DIRECTION AND OUT OF THE PRINTING PLANE), EMPLOYING BOTH EXPERIMENTAL AND SIMULATED UNIAXIAL TENSILE TESTS, A POLYNOMIAL RELATIONSHIP AS A FUNCTION OF DENSITY FRACTION IS DETERMINED. THESE DATA ARE THEN USED IN A SERIES OF SUCCESSIVE TOPOLOGICAL OPTIMIZATIONS OF A PART SUBJECTED TO OPERATIONAL LOADS THAT MAXIMIZE STRENGTH WITH A TARGETED REDUCTION IN THE OVERALL MASS. THE RESULTING OPTIMIZED PART EXHIBITS A DISCRETE DENSITY FRACTION DISTRIBUTION FROM THE OVERLAPPED TOPOLOGIES THAT ALLOWS THE TOTAL MASS OF THE ORIGINAL PART TO BE MAINTAINED WITH A 258% INCREASE IN LOAD-CARRYING CAPACITY BEFORE FAILURE AND A MERE 23% INCREASE IN FABRICATION TIME BY FUSED DEPOSITION MODELING. THESE FINDINGS UNDERSCORE THE PROMISE OF LEVERAGING ADVANCED 3D PRINTING METHODS AND TOPOLOGY OPTIMIZATION TO ENHANCE THE STRENGTH AND EFFICIENCY OF MANUFACTURED COMPONENTS.

3D-PRINTED THERMOPLASTIC PARTS WITH CONTINUOUS FIBER REINFORCEMENT ARE KNOWN TO OFFER MECHANICAL PERFORMANCE THAT IS HIGHLY DEPENDENT ON DESIGN VARIABLES AND PRINTING PARAMETERS. IN THIS WORK, THE ROLE OF THE REINFORCEMENT DISTRIBUTION ON THE MECHANICAL RESPONSE OF GLASS FIBER-REINFORCED THERMOPLASTICS PRINTED USING THE FUSED FILAMENT FABRICATION (FFF) TECHNIQUE IS EVALUATED. LAMINATES WITH ALTERNATING AND CONTINUOUS REINFORCEMENT ARCHITECTURE AS WELL AS DIFFERENT FIBER ORIENTATIONS SUCH AS ISOTROPIC (0°, 90°, AND 45°) AND CONCENTRIC CONFIGURATIONS ARE CHARACTERIZED FROM MONOTONIC TENSILE AND FLEXURAL LOADS. THE RESULTING SUPERIOR MACROMECHANICAL PERFORMANCE IN TERMS OF HIGHER STIFFNESS AND STRENGTH ACHIEVED IN SAMPLES REINFORCED WITH ALTERNATING FIBER PLIES IS CORRELATED WITH THE MICROMECHANICAL FRACTOGRAPHY CHARACTERISTICS AND INTERLAMINAR SHEAR CAPACITY.

THE DEVELOPMENT OF HIGH-ENTROPY ALLOYS HAS BEEN HAMPERED BY THE CHALLENGE OF EFFECTIVELY AND VERIFIABLY PREDICTING PHASES USING PREDICTIVE METHODS FOR FUNCTIONAL DESIGN. THIS STUDY VALIDATES REMARKABLE PHASE PREDICTION CAPABILITY IN COMPLEX MULTICOMPONENT ALLOYS BY MICROSTRUCTURALLY PREDICTING TWO NOVEL HIGH-ENTROPY ALLOYS IN THE FCC + BCC AND FCC + BCC + IM SYSTEMS USING A NOVEL ANALYTICAL METHOD BASED ON VALENCE ELECTRON CONCENTRATION (VEC). THE RESULTS ARE COMPARED WITH MACHINE LEARNING, CALPHAD, AND EXPERIMENTAL DATA. THE KEY FINDINGS HIGHLIGHT THE HIGH PREDICTIVE ACCURACY OF THE ANALYTICAL METHOD AND ITS STRONG CORRELATION WITH MORE INTRICATE PREDICTION METHODS SUCH AS RANDOM FOREST MACHINE LEARNING AND CALPHAD. FURTHERMORE, THE EXPERIMENTAL RESULTS VALIDATE THE PREDICTIONS WITH A RANGE OF TECHNIQUES, INCLUDING SEM-BSE, EDS, ELEMENTAL MAPPING, XRD, MICROHARDNESS, AND NANOHARDNESS MEASUREMENTS. THIS STUDY REVEALS THAT THE ADDITION OF NB ENHANCES THE FORMATION OF THE SIGMA (?) INTERMETALLIC PHASE, RESULTING IN INCREASED ALLOY STRENGTH, AS DEMONSTRATED BY MICROHARDNESS AND NANOHARDNESS MEASUREMENTS. LASTLY, THE OVERLAPPING VEC RANGES IN HIGH-ENTROPY ALLOYS ARE IDENTIFIED AS POTENTIAL INDICATORS OF PHASE TRANSITIONS AT ELEVATED TEMPERATURES.

THIS WORK EVALUATED THE PHASE PREDICTION CAPABILITY OF HIGH ENTROPY ALLOYS USING FOUR SUPERVISED MACHINE LEARNING MODELS K-NEAREST NEIGHBORS (KNN), MULTINOMIAL REGRESSION, EXTREME GRADIENT BOOSTING (XGBOOST), AND RANDOM FOREST. THE STUDY ADDRESSES THE CHALLENGE OF PREDICTING MULTICOMPONENT ALLOYS BY CONSIDERING THE OVERLAPPING OF MULTICATEGORICAL STABILITY PARAMETERS. EIGHT PREDICTION CLASSES (FCC, BCC, FCC+BCC, FCC+IM, BCC+IM, FCC+BCC+IM, IM AND AM) WERE USED. FINALLY, THE PREDICTED RESULTS WERE COMPARED WITH THOSE OF TWO NEW ALLOYS FABRICATED BY INDUCTION MELTING IN A CONTROLLED ATMOSPHERE USING X-RAY DIFFRACTION (XRD). THE RESULTS INDICATE THAT WITH A ROBUST DATABASE, APPROPRIATE DATA TREATMENT, AND TRAINING, SATISFACTORY AND COMPETITIVE PREDICTION INDICATORS CAN BE OBTAINED WITH TRADITIONAL MACHINE LEARNING PREDICTIONS BASED ON FOUR PREDICTION CLASSES: SOLID SOLUTION (SS), SOLID SOLUTION WITH INTERMETALLIC (SS+IM), INTERMETALLIC (IM), AND AMORPHOUS (AM). THE BEST PREDICTIVE MODEL OBTAINED FROM THE FOUR EVALUATED MODELS WAS RANDOM FOREST, WITH AN ACCURACY OF 72.8% AND ROC AUC OF 93.1%.

DEVELOPMENT OF BIOCOMPATIBLE POROUS SUPPORTS IS A PROMISING STRATEGY IN THE FIELD OF TISSUE ENGINEERING FOR THE REPAIR AND REGENERATION OF BONE TISSUES WITH SEVERE DAMAGE. GRAPHENE OXIDE AEROGELS (GOAS) ARE EXCELLENT CANDIDATES FOR THE MANUFACTURE OF THESE SYSTEMS DUE TO THEIR POROSITY, ABILITY TO IMITATE BONE STRUCTURE, AND MECHANICAL RESISTANCE, AND ACCORDING TO THEIR SURFACE CHEMICAL REACTIVITY, THEY CAN FACILITATE OSSEOINTEGRATION, OSTEOGENESIS, OSTEOINDUCTION AND OSTEOCONDUCTION. IN THIS REVIEW, SYNTHESIS OF GOAS FROM THE MOST PRIMARY SOURCE IS DESCRIBED, AND RECENT STUDIES ON THE USE OF THESE FUNCTIONALIZED CARBONACEOUS FOAMS AS SCAFFOLDING FOR BONE TISSUE REGENERATION ARE PRESENTED.

THE PRESENT STUDY IS AN ANALYSIS OF DIFFERENT INVESTIGATIONS OF HIGH ENTROPY ALLOYS IN DIFFERENT FIELDS OF APPLICATION AND THEMES, BUT WHICH CONVERGE IN THE LINE OF MECHANICAL BEHAVIOR AT CRYOGENIC TEMPERATURES AND HIGH TEMPERATURES WITH THE MAIN FOCUS ON THE MICROSTRUCTURE AND ITS CONSTITUTION POTENTIAL THROUGH THERMODYNAMICS. THE REVISED CHAPTERS ARE PRECISELY THE THERMODYNAMIC AND METALLURGICAL FOUNDATIONS THAT GOVERN THE DESIGN OF HIGH ENTROPY ALLOYS, INTRODUCE IN THEIR DIFFERENT APPLICATIONS IN THE FIELDS OF ENERGY, AEROSPACE, METAL SHAPING, AND ADVANCED MANUFACTURING, PREDICTIVE THERMODYNAMICS, MICROSTRUCTURAL ANALYSIS AND THEIR IMPORTANCE IN THE MECHANICAL BEHAVIOR AND FORMATION OF STRENGTHENING MECHANISMS, TO END WITH THE ANALYSIS OF THE WHOLE DOCUMENT IN THE APPLICATION OF THE MECHANICAL RESPONSE OF HIGH ENTROPY ALLOYS IN CONDITION OF HIGH TEMPERATURES AND CRYOGENIC TEMPERATURES IN ADDITION TO DYNAMIC LOADS SUCH AS FATIGUE AND REFLECTING THE IMPORTANCE OF THE MANUFACTURING PROCESS AND THE MICROSTRUCTURE HAS IN THE PERFORMANCE AT WORKING CONDITIONS, LEAVING IN EVIDENCE THE DEPENDENCE OF THE MICROSTRUCTURE AND ITS DEFECTS AS WELL AS ITS PRESENT PHASES ALLOW TO OBTAIN A GOOD BEHAVIOR AT MACROSCOPIC LEVEL. FOR THIS REASON, THE ANALYSIS OF THE EVALUATION OF MECHANICAL BEHAVIOR WAS ALSO LINKED THROUGH MULTISCALE ANALYSIS THROUGH DIFFERENT APPLIED METHODOLOGIES AND HOW THEY ARE COMBINED IN A WAY COUPLED TO THE TIME AND SPACE ACCESS SYSTEM.