Decrease In Ultimate Tensile Strength Research Articles

Study of oxidation behavior and tensile properties of candidate superalloys in the air ingress simulation scenario

Air ingress incidents are major safety accidents in very-high-temperature reactors (VHTRs). Air containing a high volume fraction of oxygen may cause severe oxidation of core components at the VHTR, especially for the significantly thin alloy tube wall in the intermediate heat exchanger (IHE). The research objects of this study are Inconel 617 and Incoloy 800H, two candidate alloys for IHE in VHTR. The air ingress accident scenario is simulated with high-temperature air flow at 950 °C. A continuous oxide scale was formed on the surfaces of both the alloys after the experiment. Because the oxide scale of Inconel 617 has a loose structure, whereas that of Incoloy 800H is denser, Inconel 617 exhibited significantly more severe internal oxidation than Incoloy 800H. Further, Inconel 617 showed a significant decrease in ultimate tensile strength and plasticity after aging for 200 h, whereas Incoloy 800H maintained its tensile properties satisfactorily. Through control experiment under vacuum, we preliminarily concluded that serious internal oxidation is the primary reason for the decline in the tensile properties of Inconel 617.

Role of Al element in tailoring the austenite mechanical stability and tensile properties of medium Mn steels

Al is generally employed as a key alloying element to tailor the austenite mechanical stability and mechanical properties in medium Mn TRIP steels. However, the effect of Al on the austenite stability has been limitedly studied, leaving contradictory results without a self-consistent explanation. This study addressed this issue through a systematic study of medium Mn TRIP steels with compositions of 0.2C–8Mn-0/1.5/3Al (wt.%), while providing new insights into the factors influencing austenite stability and mechanical properties. It was found that the variation of the Mn distribution in austenite from non-equilibrium to near-equilibrium state and the weakened strain incompatibility between phases due to sufficient recovery of tempered martensite can be achieved with the addition of Al, which contributed to slowed strain-induced martensite transformation (SIMT) and improved austenite stability in the experimental steels annealed at low temperatures in the two-phases region, resulting in a decrease in ultimate tensile strength (UTS) and an increase in total elongation (TE). Furthermore, fully recovered tempered martensite with the hardness much lower than that of austenite was obtained in the 3Al steel annealed at a high temperature in the two-phase region, which led to a significant reduction in yield strength and thus low UTS. Meanwhile, heterogeneous strain distribution was induced by the remarkable gap in hardness between the two phases, which can be responsible for the relatively high austenite mechanical stability. The varying strain states and variation of Mn distribution in austenite can be achieved for the medium Mn TRIP steels with different Al contents, contributing to a wide range of UTS&TE combination with high strength and elongation product (≥40 GPa·%). And the elucidation of the effect of different strain states also opens a new window to adjust the austenite stability and mechanical properties of medium Mn TRIP steels.

Probing the stochastic fracture behavior of twisted bilayer graphene: Efficient ANN based molecular dynamics simulations for complete probabilistic characterization

The present article outlines a probabilistic investigation of the uniaxial tensile behaviour of twisted bilayer graphene (tBLG) structures. In this regard, the twist angle (θ) and temperature (T) are considered as the control parameters and the ultimate tensile strength (UTS) and failure strain of the tBLG structures are considered as the responses. It is observed that with the increase in twist angle (θ) of tBLG; the fracture responses exhibit a declining trend deterministically. The tBLG twisted with the magic angle (θ = 1.08o) results in around 7% decrease in UTS and nearly 24% decrease in failure strain, when compared with normal BLG (θ = 0̊). The Monte Carlo simulation (MCS) based random sampling is performed for the considered control parameters, wherein θ is varied from 0o to 30o, and temperature is varied from 100 K to 900 K. Within such bounds of the input parameters, the training (64 samples) and validation (8 samples) sample spaces are constructed. In the next step, molecular dynamics (MD) simulation of uniaxial tensile deformation of the modelled tBLG structures is carried out for each instance of the sample space. The dataset is subsequently used to form and validate the artificial neural network (ANN). The computationally efficient machine learning (ML) model is further utilized to perform the detailed investigation of fracture behaviour of the tBLG structures in the probabilistic framework. Such analysis captures all the possible instances of variation in the input parameters and leads to deep insights in the material behaviour, which would have otherwise remained unnoticed due to the prohibitive nature of conducting a large number of MD simulations. The novelty of the present study lies in the probabilistic interpretation of the tensile behaviour of tBLG structures subjected to variation in twist angle (θ) and temperature (T). The preparation of nano-scale samples with the exact design specifications such as twist angle is often extremely difficult, which leads to inevitable stochastic system disorders. The current article essentially proposes a probabilistic avenue of quantifying the effect of such disorders on the failure properties of tBLG.

Effects of the tempering temperature on microstructure and mechanical properties of X70 dual phase steel

This study uses direct quenching (DQ) heat treatment at an intercritical annealing temperature (IAT) of 800 °C to form a martensite-ferrite dual phase microstructure of X70 steel. The effects of tempering temperatures ranging from 200 to 500 °C on tensile properties in a dual-phase X70 steel are investigated. Carbon diffusion and redistribution in the microstructure are influenced by tempering. It was discovered that the amount of carbides increases with the tempered temperature, resulting in depleted carbon in martensite. Conversely, increasing the tempered temperature causes a decrease in ultimate tensile strength and yield strength while increasing elongation.

Microstructural evolution in CoCrFeNi and CoCrCuFeNi alloys processed by autogenous fusion welding

In this work, CoCrFeNi and CoCrCuFeNi multi-principal element alloys were welded using an autogenous gas tungsten arc welding process. Tensile testing, microhardness, X-ray diffraction, scanning electron microscopy, electron back scattered diffraction techniques were used to study the mechanical properties, crystal structure and microstructures of the base metals (BMs) and welds. It was found that CoCrFeNi alloy was easily weldable while CoCrCuFeNi alloy produced transverse cracks. Only 13.5% decrease in ultimate tensile strength as compared to its BM was observed in CoCrFeNi alloy. Whereas poor tensile properties were observed in CoCrCuFeNi alloy due to Cu segregation and micro-cracks. Fractography analysis of the BM and weld specimen shows ductile failure in both the alloys.

Achieving enhanced high-temperature mechanical properties in Mg-Nd-Sm-Zn-Ca-Zr alloy by Ag addition

Mg alloys have been attracting particular interests in industrial manufacture. Nevertheless, the poor high-temperature mechanical properties of Mg alloys limit their further practical applications. Thus, as-cast Mg-2.5Nd-1.0Sm-0.4Zn-0.1Ca-0.5Zr-xAg (x = 0, 0.5, 1.0, 1.5, 2.0 wt%) alloys were designed and fabricated to overcome this shortcoming in this study. The influences of Ag addition on the microstructures and mechanical properties of Mg alloys were analyzed in detail. The results indicated that the microstructures of the alloy were composed of equiaxed α-Mg grains and β phase. The content of the β phase increased from 5.56% to 8.91% upon increasing the content of Ag from 0 wt% to 2.0 wt%, indicating that Ag can promote the formation of the β phase significantly. Moreover, the first-principles calculations supported that the formation enthalpy for the β phase was reduced with the doping of Ag resulting in increased stability of the β phase. Ag also enhanced the bulk modulus and ductility of the β phase. Meanwhile, the Young's modulus and elastic anisotropy of the β phase was diminished by Ag addition. The addition of Ag increased the strength and decreased the elongation of the as-cast alloys. The as-cast alloy with 2.0 wt% Ag addition achieved comprehensive mechanical properties. Furthermore, the as-cast alloy with 2.0 wt% Ag addition showed the least decrease in ultimate tensile strength with increasing temperature compared to the other alloys. The ultimate tensile strength of the as-cast alloy with 2.0 wt% Ag addition decreased from 196.0 MPa to 188.8 MPa as the temperature changed from 25 °C to 275 °C. The increase in strength and heat resistance of the alloys is mainly attributed to the increased β phase content and stability. Overall, this work developed a new heat resistant Mg-Nd-Sm-Zn-Ca-Zr-Ag alloy with excellent high-temperature mechanical properties. This suggests that it helps to improve the high-temperature mechanical properties and reliability of new aero engines and promote applications of lightweight engines.

Effect of partial recrystallization on microstructure and tensile properties of NiFeCoCrMn high-entropy alloy

To obtain a balance between strength and ductility in NiFeCoCrMn high-entropy alloy, the degree of dislocation strengthening was tuned via partial recrystallization during traditional thermomechanical processing (cold rolling and recrystallization). The tensile properties in each state were then examined. Significant improvements in uniform elongation and work hardening rate, with decrease in yield strength and ultimate tensile strength, are associated with increase in the recrystallized fraction, i.e., reductions in the degree of strain hardening. In particular, recrystallized fractions of 37% and 74% are obtained by annealing at 650 °C for 10 min and 15 min, respectively, which results in yield strengths of 1003 MPa and 742 MPa and uniform elongations of 4% and 24%, respectively. The strengthening is due to the unrecrystallized grains with a high density of dislocations, whereas the ductility benefits from the presence of recrystallized strain-free grains.

Precipitation behavior and tensile properties of A356.2 alloy with different high temperature pre-precipitation temperatures

In order to understand the effect of high temperature pre-precipitation (HTPP) temperature on the precipitation behavior and tensile properties of A356.2 alloy treated by Al-6Sr-7La master alloy, SEM, TEM and tensile tests were applied to investigate the evolution of fracture morphology and precipitates of the alloys under different HTPP temperatures. The results showed that ultimate tensile strength (UTS) and yield strength (YS) of the alloys decrease and elongation (El) increases with HTPP temperature decreasing. When HTPP temperature decreased from 510 °C to 470 °C coarsen coherent β″ phase appear in α-Al matrix, continue to decrease HTPP temperature to 450 °C the main precipitate transformed into semi-coherent β′ phase, leading to the change in mechanical properties. In addition, coarsening and transformation of the precipitate were attributed to the reduction of Si concentration which decreases with HTPP temperature decreasing. Moreover, Si nanoparticles precipitated in α-Al matrix, leading to the decrease of UTS and YS to certain extent due to reducing Si concentration during aging process.

Comparison of Mechanical and Corrosion Properties for 17-4 PH Stainless Steel Fabricated by Metal Injection Moulding Using Varied Powder Sizes

17-4 PH stainless steel is commonly used in sev eral engineering applications because of the combined good mechanical properties and high corrosion resistance. Metal injection moulding (MIM) was used to fabricate 17-4 PH stainless steel specimen with three mean powder sizes (D50), which are 2.82, 4.04 and 12.65 μm. The rheology of three feedstocks were investigated using melt flow index (MFI) and viscosity analysis. Feedstocks were injected at 170 °C. Injected tensile specimens were sintered at 1325 °C for 2 h in argon atmosphere. Surface roughness (Ra) measurement, relative density measurement, tensile test and hardness test (HRC) were carried out. Corrosion properties were determined by cyclic polarisation tests. The results indicated that the relative density of sintered samples is higher than 98% (7.68-7.74 g/cm3). α-Fe (bcc-martensite), δ-Ferrite (delta ferrite) and also SiO2 were observed in all sintered samples, which were detected by scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS). As the mean powder size of injected specimens increases, the elongation and hardness increase, whereas the ultimate tensile strength (UTS) and surface roughness decrease. Moreover, the specimens using the smallest powder (2.82 μm) have shown better corrosion resistance than the specimens using the larger powders as the higher potentials in term of E-pit (the potential of pitting) and E-rep (the potential of repassivation) and the lower potential in term of E-cor (the potential of corrosion).

The Effect of Ti–B and Sr on the mechanical behaviour of the Zinc–Aluminum-based ZA-12 alloy produced by gravity casting

Abstract In this study, the effect of Ti –B (0.05 – 0.7 wt.% Ti, 0.01 – 0.13 wt.% B) and Sr additions (0.05 – 0.7 wt.%) on the hardness, ultimate tensile strength (UTS), strain and fatigue properties of the gravity cast Zn – Al-based ZA-12 alloy was investigated. While the Ti –B additions had no significant effect on the hardness of the alloys, the Sr additions lowered the hardness by a small amount. UTS and fatigue resistance of the ZA-12 alloy increased with 0.05 wt.% Ti, but the addition of 0.05 wt.% Sr to the standard alloy did not change these properties significantly. In excess of 0.05 wt.% Ti and Sr, the UTS and fatigue resistance of the alloys decreased and reached a lower value than that of the standard alloy. The failure strain only increased for the ZA-12 alloy containing 0.05 wt.% Ti, then decreased with further increase in Ti content. The failure strain values of the alloys decreased with addition of Sr. Metallographic examination indicated that the addition of Ti –B strongly modified the microstructure of the standard ZA-12 alloy, but Sr did not. Ti and Sr have also formed complexshaped intermetallic compounds, which were identified as Al5Ti2Zn and Zn5Al3Sr by X-ray diffraction and EDS analyses. It can be suggested that these particles cause a decrease in UTS, fatigue resistance, and strain to failure of the ZA-12 alloy.

Correlation between quasistatic und fatigue properties of additively manufactured AlSi10Mg using Laser Powder Bed Fusion

In order to find a resource efficient approach for the fatigue lifetime prediction of laser powder bed fusion (L-PBF) processed AlSi10Mg material, results of tensile and fatigue tests were compared. The specimens were manufactured with three different L-PBF machines and studied in different heat treatment conditions (as-built, annealed, T6 heat treated). The investigations showed that the high attainable tensile strength properties after the manufacturing process are not beneficial in the high cycle fatigue (HCF) regime. In contrast, the applied heat treatments, which lead typically to a decrease of ultimate tensile strength, improved dramatically the fatigue behavior. Additionally, a clear correlation between the elongation at fracture and HCF resistance has been found for individual heat treatment conditions. This empiric relationship provides an estimation of the fatigue resistance in the presence of material defects and can be implemented in part and process approvals.

MECHANICAL PROPERTIES OF UNALLOYED TITANIUM VT1-0 PROCESSED USING SELECTIVE LASER MELTING AND SEVERE PLASTIC DEFORMATION

Unalloyed titanium VT10 with a record value of the ultimate tensile strength of 1350 MPa obtained using technologies of selective laser melting and rotary swaging. This value exceeds by 3 times the tensile strength of commercially pure titanium produced using conventional technologies and also exceeds the strength values of Ti6Al4V (grade 5) high strength titanium alloy. The reasons of the increase in the strength characteristics of titanium VT10 are the finedispersed marten site obtained due to high crystallization rates in the process of selective laser melting, and its additional refinement during the rotary swaging process. To study the thermal stability of the mechanical properties of titanium VT10 processed using various technologies, research of the effect of annealing temperature in the range of 100–800 °C on the ultimate tensile strength and elongation to failure were carried out. Results have shown that the dependence of the ultimate tensile strength on the annealing temperature for VT10 titanium samples after selective laser melting and rotary swaging has a threestage behavior. The ultimate tensile strength decrease by 25–35% after heat treatment at 800 °C. The values of elongation to failure for VT10 titanium samples processed by selective laser melting and rotary swaging monotonically increase from 8–12 to 18–23% when the annealing temperature grows up to 800 °C. The possibilities of methods of selective laser melting, rotary swaging and heat treatment to control the mechanical characteristics of titanium VT10, which is a promising material for the manufacture of osteointegrable medical implants, are demonstrated. The combined application of the abovementioned methods makes it possible to produce VT10 titanium with a given combination of strength and plastic characteristics in a wide range of values.

Effect of heat treatment on microstructure, hardness and tensile properties of high-speed selective laser melted Ti6Al4V

This study presents the investigation of the influence of heat treatment on microstructure, hardness and tensile properties of high-speed selective laser melted Ti6Al4V components. Heat treatment was performed to obtain an improved microstructure with enhanced hardness and tensile properties. It was found that the acicular martensitic α′ structure on the as-built sample lead to high hardness, yield strength and ultimate tensile strengths of 389±10 HV0.3, 949 ± 10 MPa and 1045 ± 3 MPa, respectively,with a low ductility of 5%. Heat treatment transformed the martensitic α′ structure into lamella α + β phases, with heat treatment at 1000 °C resultingin the most improved hardness and ductility from 389 ± 10 HV0.3and 5% to 325 ± 20 HV0.3and 13%, and a decrease in yield and ultimate tensile strength from 949 ± 10 MPa and 1045 ± 13MPa to 835 ± 11 MPa and 911 ± 5 MPa, respectively.

Microstructure and mechanical properties of Ti-6.5Al-2Zr-Mo-V alloy processed by Laser Powder Bed Fusion and subsequent heat treatments

In this work, near-α Ti-6.5Al-2Zr-Mo-V alloys were successfully fabricated through Laser Powder Bed Fusion (LPBF) and subjected to post-heat treatments. A comparative study on the microstructure and mechanical properties of different samples was performed to reveal the effects of LPBF process parameters and post-heat treatments. The optimal LPBF process window for fabricating relative density > 99.9% samples is located in the volumetric energy density (VED) range of 125–167 J/mm3. The extremely rapid cooling rate in LPBF induced a full martensite α′ structure. Substructures characterized by low angle grain boundaries (LAGBs), tangled high angle grain boundaries (HAGBs), and several inter-variants were found in the as-built samples. In the optimal VED range, no significant microstructural difference among the samples was found. This resulted in a stable level of mechanical properties for the optimal as-built samples: 1172–1227 MPa in ultimate tensile strength (UTS), 7.9–8.8% in elongation, ~ 425 Hv in microhardness. After sub-β heat treatments, the LPBF-induced substructures of LAGBs and HAGBs were gradually eliminated, resulting in a decrease in UTS but an increase in elongation. An increase of ~ 57° boundaries was found in the HT700 and HT800 samples, suggesting a boundary transformation during the recrystallization. The transformation is beneficial to the mechanical property. It contributed to a small drop of UTS (~20 MPa) for the HT700 and HT800 samples and significantly improved ductility compared with the as-built samples. The HT900 sample underwent complete recrystallization with an α-lath dominated structure. Thereby it exhibits a better ductility but a lower UTS compared with the HT700 and HT800 samples. After the super-β heat treatments, a large amount of martensite reappeared. Due to the large size of prior β grains, the ductility was significantly decreased. The results of this study can be used to guide the adjustment of the microstructure of LPBF-processed Ti-6.5Al-2Zr-Mo-V alloy through post-heat treatments to obtain a good combination of tensile properties.

Additive Manufacturing and Characterization of Metal Particulate Reinforced Polylactic Acid (PLA) Polymer Composites.

Affordable commercial desktop 3-D printers and filaments have introduced additive manufacturing to all disciplines of science and engineering. With rapid innovations in 3-D printing technology and new filament materials, material vendors are offering specialty multifunctional metal-reinforced polymers with unique properties. Studies are necessary to understand the effects of filament composition, metal reinforcements, and print parameters on microstructure and mechanical behavior. In this study, densities, metal vol%, metal cross-sectional area %, and microstructure of various metal-reinforced Polylactic Acid (PLA) filaments were characterized by multiple methods. Comparisons are made between polymer microstructures before and after printing, and the effect of printing on the metal-polymer interface adhesion has been demonstrated. Tensile response and fracture toughness as a function of metal vol% and print height was determined. Tensile and fracture toughness tests show that PLA filaments containing approximately 36 vol% of bronze or copper particles significantly reduce mechanical properties. The mechanical response of PLA with 12 and 18 vol% of magnetic iron and stainless steel particles, respectively, is similar to that of pure PLA with a slight decrease in ultimate tensile strength and fracture toughness. These results show the potential for tailoring the concentration of metal reinforcements to provide multi-functionality without sacrificing mechanical properties.

Work Hardening of Heat-Treated AlSi10Mg Alloy Manufactured by Selective Laser Melting: Effects of Layer Thickness and Hatch Spacing.

The present study analyzed the microstructure and the mechanical properties of AlSi10Mg SLMed bars (10 × 10 × 300 mm) and billets (10 × 100 × 300 mm) before and after the direct aging at 200 °C for 4 h and the T6 heat treatment. The discussed results are compared to those obtained by the AlSi10Mg samples manufactured with the same geometry but using different process parameters (layer thickness higher than 40 μm and a hatch spacing lower than 100 μm) and also through the Quality Index (QI). These work conditions allow the obtaining of a microstructural variation and different tensile properties in as-built top samples. In both batches, the cycle time was 45 h and together with the preheated build platform at 150 °C, induced an increase of UTS (Ultimate Tensile Strength) and yield strength on the bottom rather than the top samples due to the aging phenomena. Upon completion of the direct aging heat treatment, the effects induced by the platform were cancelled, keeping a full cellular microstructure that characterized the as-built SLMed (Selective Laser Melted) samples. Moreover, the Considère criterion and the work hardening analysis showed that the failure occurs after the necking formation in some of the T6 heat-treated samples. In this last case, the Si eutectic network globularized into Si particles, causing a decrease of UTS (from around 400 MPa to 290 MPa) in favour of an increase of ductility up to 15% and reaching a QI in the range 400 ÷ 450 MPa. These values place these samples between the high-quality aluminium cast alloy and T6 heat-treated ones.

Effect of Pre-Strain on Microstructure and Tensile Properties of Ti-6Al-4V at Elevated Temperature

Research on pre-deformation influences on material properties in multistep hot forming is of important scientific interest. In this paper, hot tensile tests at 850 °C and a strain rate of 0.001 s−1 were performed to study the microstructural evolution and mechanical properties of Ti-6Al-4V with pre-strains at 0.05, 0.1 and 0.15. The tensile test results showed that the specimen with 0.05 pre-strain exhibited higher flow stress and larger elongation. Additionally, increasing the pre-strain resulted in a decrease in ultimate tensile strength (UTS) and elongation (EL). The EBSD results showed that the main deformation mechanism of Ti-6Al-4V was high-angle grain boundary sliding. Pre-strain promoted dynamic recrystallization (DRX) by increasing the deformation substructure. The refinement of grains and the eradication of dislocations enhanced the deformability, resulting in an increase in flow stress.

Effect of temperature on the mechanical properties of Al–Si–Cu–Mg–Ni–Ce alloy

High-temperature performance is a key factor to concern for the application of cast Al–Si alloys. The evolution of microstructures and mechanical properties of a multiphase Al–Si–Cu–Mg–Ni–Ce alloy during tension in a temperature range from 25 °C (ambient temperature) to 425 °C was investigated. The results show that the main strengthening precipitates of the alloy are θ′ and Q phases. They are stable at 25–250 °C, while dissolve rapidly above 250 °C during tension. The damage initiates and propagates in the form of cracking of brittle phases. The fracture mechanism transforms from quasi-cleavage to coexistence of quasi-cleavage and dimple as temperature increases. The Ce-bearing phase Al20Ti2Ce promotes the damage occurrence below 350 °C while hinders crack propagation at 425 °C. The ultimate tensile strength (UTS) and yield strength (YS) decrease as the tensile temperature increases. The decreasing rate of UTS can be divided into three stages which is associated with the decreasing rate of strengthening precipitates. An empirical constitutive equation is proposed to describe the relationship between UTS and tensile temperature. It provides a good estimation for both cast and wrought Al alloys and the predicted strengths are in good agreement with the experimental results.

Stressed-oxidation behavior of 2D CVI SiC/BN/SiC at elevated temperature in air

The stressed-oxidation behaviors of 2D woven SiCf/BN/SiC composites were investigated at 950 °C and 1100 °C in air. The different proportions (60%–90%) of the ultimate tensile strength (UTS) at corresponding temperatures were chosen as constant stress. The stressed-oxidation experiments were taken to failure or interrupted (240h). The UTS decreases by 20.75% at 950 °C and 30.71% at 1100 °C. The composites did not fail during stressed oxidation when subjected to constant stress corresponding to the initial linear and the beginning of nonlinear segments of the tensile curve, above which the composites failed with a maximum failure life of about 10h. Fiber degradation due to the thermal exposure and the fiber cracks caused by the oxidation of BN interface coating and SiC fiber could be responsible for the strength degradation and failure of the composites during stressed oxidation.

Size effects on microstructure and mechanical properties of additively manufactured copper–chromium–niobium alloy

This study quantifies size effects on microstructure and mechanical properties of Laser Powder Bed Fusion (L-PBF) Copper–Chromium–Niobium Alloys, specifically GRCop-42 (Copper-4at% Chromium-2at% Niobium Alloy). Thin-wall structures made of copper-based alloys are desirable for applications requiring a combination of high thermal conductivity and strength. Additive manufacturing offers the ability to produce copper alloy thin-wall structures without the need for complex tooling. However, consideration must be given to the effect of wall thickness on solidification rate and process as it can affect material and part characteristics including the microstructure, porosity, and surface roughness. This investigation aims to determine which of these characteristics are most influenced by variations in wall thickness and how they affect the mechanical properties. Additionally, we investigate how these characteristics and their influence on mechanical properties are changed by heat treatment. The results show that surface roughness, grain size, and texture do not appear to be greatly influenced by the build thickness, while porosity appeared to be highly dependent on thickness. By increasing wall thickness from 0.7 mm to 2.0 mm, porosity decreases by 74.7% in the as-built condition and 99.7% in the hot isostatic press (HIP) condition. The variability in porosity has a notable effect on the mechanical properties of the thin-wall structures: yield strength and ultimate tensile strength decrease by more than 20% for both as-built and HIP samples as thickness decreases from 2.0 mm to 0.7 mm. This decrease in strength appears to be attributable to the increased porosity in thin-wall samples, as scanning electron microscopy (SEM) images show crack networks linking internal voids along the fracture surface.