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AlSi10Mg alloy is commonly used in laser powder bed fusion due to its printability, relatively high thermal conductivity, low density and good mechanical properties. However, the thermal conductivity of as-built materials as a function of processing (energy density, laser power, laser scanning speed, support structure) and build orientation, are not well explored in the literature. This study aims to elucidate the relationship between processing, microstructure, and thermal conductivity.

The thermal conductivity of laser powder bed fusion (L-PBF) AlSi10Mg samples are investigated by the flash diffusivity and frequency domain thermoreflectance (FDTR) techniques. Thermal conductivities are linked to the microstructure of L-PBF AlSi10Mg, which changes with processing conditions. The through-plane exceeded the in-plane thermal conductivity for all energy densities. A co-located thermal conductivity map by frequency domain thermoreflectance (FDTR) and crystallographic grain orientation map by electron backscattered diffraction (EBSD) was used to investigate the effect of microstructure on thermal conductivity.

The highest through-plane thermal conductivity (136 ± 2 W/m-K) was achieved at 59 J/mm³ and exceeded the values reported previously. The in-plane thermal conductivity peaked at 117 ± 2 W/m-K at 50 J/mm³. The trend of thermal conductivity reducing with energy density at similar porosity was primarily due to the reduced grain size producing more Al-Si interfaces that pose thermal resistance. At these interfaces, thermal energy must convert from electrons in the aluminum to phonons in the silicon. The co-located thermal conductivity and crystallographic grain orientation maps confirmed that larger colonies of columnar grains have higher thermal conductivity compared to smaller columnar grains.

The thermal properties of AlSi10Mg are crucial to heat transfer applications including additively manufactured heatsinks, cold plates, vapor chambers, heat pipes, enclosures and heat exchangers. Additionally, thermal-based nondestructive testing methods require these properties for applications such as defect detection and simulation of L-PBF processes. Industrial standards for L-PBF processes and components can use the data for thermal applications.

To the best of the authors’ knowledge, this paper is the first to make coupled thermal conductivity maps that were matched to microstructure for L-PBF AlSi10Mg aluminum alloy. This was achieved by a unique in-house thermal conductivity mapping setup and relating the data to local SEM EBSD maps. This provides the first conclusive proof that larger grain sizes can achieve higher thermal conductivity for this processing method and material system. This study also shows that control of the solidification can result in higher thermal conductivity. It was also the first to find that the build substrate (with or without support) has a large effect on thermal conductivity.

This study aims to uncover the multiscale relations among geometry, surface finish, microstructure and fatigue properties of curved-surface AlSi10Mg parts fabricated by powder bed fusion (PBF) additive manufacturing.

This paper investigated the high-cycle tensile and bending fatigue behaviors of PBF-built AlSi10Mg parts with curved surfaces. Besides, the surface finish, porosity and microstructure around various curvatures were characterized. Meanwhile, the stress distributions of the fatigue specimens with curved surfaces under the dynamic tensile/bending loading were analyzed via theoretical analysis and ANSYS simulation.

The results showed that the as-built specimens with the smallest curvature exhibited the best surface quality, smallest grain sizes and thinnest grain boundaries. In addition, the tensile fatigue fracture occurred around the largest curvature position of fatigue specimens, which was consistent with the simulated fatigue safety factor results. Moreover, the bending fatigue specimens with the largest curvature presented the shortest fatigue life due to the highest bending and shear stresses along the loading direction.

So far, most studies have focused on the fatigue behavior of as-built AlSi10Mg parts with planar structures only. The investigation on fatigue properties of as-built AlSi10Mg parts with curved surfaces remains unexplored. This study provides new insights into the characterization and quantification of the fatigue performance of PBF-built metal parts with complex geometries, the knowledge of which can promote their adoption in real industries.

The aim of the present study was to investigate the association of the empirical dietary index for insulin resistance (EDIR) and empirical lifestyle index for insulin resistance (ELIR) with the risk of nonalcoholic fatty liver disease (NAFLD) in Iranian adults.

In this case-control study, 120 cases of NAFLD and 240 controls aged ≥20 years were included. NAFLD was detected by a gastroenterologist using an ultrasonography test. The food frequency questionnaire was used to collect nutritional data and determine the score of EDIR in participants. ELIR was determined based on body mass index, physical activity and dietary pattern. The odds ratios (ORs) of NAFLD were reported across tertiles of EDIR and ELIR using a logistic regression test.

The mean±SD age and BMI of subjects were 41.8 ± 7.5 years and 27.4 ± 2.2 kg/m², respectively. In the age and sex-adjusted model, the odds of NAFLD were increased across tertiles of ELIR (OR = 3.00; 95% CI: 1.63–5.55, P_trend = 0.001). Also, based on the fully adjusted model, the odds of NAFLD were increased according to tertiles of ELIR (OR = 2.66; 95% CI: 1.38–5.10, P_trend = 0.006). However, no significant association was found between the higher score of EDIR and odds of NAFLD based on the age and sex-adjusted model (OR = 1.18; 95% CI: 0.68–2.05, P_trend = 0.52) and the multivariable-adjusted model (OR = 0.91; 95% CI: 0.48–1.70, P_trend = 0.87).

To the best of the authors’ knowledge, this was the first study to examine the role of the insulinemic potential of diet and lifestyle in predicting NAFLD risk. Our findings suggested that a lifestyle with a higher score of ELIR was positively associated with NAFLD risk. However, a diet with a higher score of EDIR was not related to the odds of NAFLD.