Sintering by the TiH2 and Ti powder compaction was performed at 1423∼1623K for 2hours 1.33x10-3Pa. The sinter-ability of higher than that pure titanium powder, leading to near 99% relative density, which competing level with HIP process. In direct sintering compaction, interstitial hydrogen atoms released before through grain boundaries meet oxide phase existing in as film forms. We found thermodynamically there could effectively reduce on surfaces or a considerable driving force about -250...

In selective laser melting (SLM), powder properties like size, distribution, shape, flow, and packing have effects on the process final parts quality, several standards methods are available for representing these characteristics. However, not enough to explain actual state of particles across bed substrate. This work reports a novel method evaluation layer density in SLM process. The results show that characteristics measured by conventional always appropriate determining whether material...

Abstract The process window of selective laser melting (SLM), a set optimum parameters, is crucial for producing defect-free components with excellent mechanical properties. This study aims to predict the SLM stainless steel by varying defocusing distance (f) which changes beam diameter (d) and using power (P) scan speed (V) as parameters. was predicted empirical formulae related energy density equations, instead conventional approach based on simple experimental results. To window, we...

We have performed theoretical analysis of thermal expansion behavior alumina crystals under finite temperature based on first principles phonon state calculations. Liner coefficients a pure α-alumina crystal been evaluated quasi-harmonic approximation including crystalline anisotropy. The Cr doping effect the has also examined and found that can cause noticeable change coefficient. present results demonstrate approach be helpful for reproducing or predicting behaviors dopant effects, which...

SUMMARY The Fourier series is employed to approximate the input/output (I/O) characteristics of a dynamic system and, based on approximation, new learning control algorithm proposed in order find iteratively input for tracking desired trajectory. use approximation I/O renders at least couple useful consequences: frequency can be used controller design and reconstruction states not required. convergence condition provided existence uniqueness discussed. effectiveness illustrated by computer...

The PbTiO3/SrTiO3 superlattice thin films with a low volume fraction of PbTiO3 have not attracted much interest because they are thought to exhibit only paraelectric state. In this study, we focus on film (PTO) and thick SrTiO3 (STO) layers, wherein the hidden ferroelectricity in layer is revealed. Atomic scale imaging analysis electron energy loss spectroscopy reveal existence disordered ferroelectric polarization state without innate tetragonal distortion (6PTO/15STO)5 superlattice....

Authors investigated the potential application of vacuum membrane distillation (VMD) to conventional ocean thermal energy conversion (OTEC). Open, closed, and hybrid cycles OTEC are reviewed, strategies enhance performance open cycle (OC) using VMD discussed. The advantages modular sets include reducing system sizes enhancing power production rates. Our rough estimation indicates that uses only about 10 per cent volume required by OC-OTEC. Tasks actualize promising technology discussed for...

Tungsten carbide (WC) in Ni-based powders is a promising candidate for laser-based additive manufacturing because WC an extremely hard material, whereas Ni tough and weldable. However, particles that are directly exposed to laser beam can be degraded or disintegrated into tungsten carbon as result of excess energy. In contrast, the melt pool relatively stable. this study, direct energy deposition method was used with irregular spherical metal powder. Irregular were found more affected by...

This study investigates the challenges of additively manufactured interlocking structures, emphasizing joinability issues due to thermal deformation. These become pronounced when fabricating high-density structures without fully interconnected layers, a trait common in soft magnetic materials. Here, detailed analysis assessing deformation concerning pin thickness and build orientation representative model is performed. Utilizing stress simulations additive manufacturing process, it shown...

Synthesizing helical nanostructures by the noncovalent bonded supramolecular coassembling method has received much attention because it versatile applications in biological systems. Generating polymer structures using circularly polarized (CP) light as a source been limited due to lack of molecular designs. Herein, we use new organogel sample state get right- and left-helical nanoribbons produced left-CP irradiation. The system consists long-chain amidoamine (C18AA) 10,12-pentacosadiynoic...

Abstract In this paper, the following two important issues of iterative learning control are considered : i) robustness to initial error and ii) convergence in sense sup-norm. The main theme paper is how design an controller order make algorithm be more robust and/or guarantee exponential To end, we restrict our attention PD-type law study its properties about issues. results show that pure term closely related Based on investigated law, a guide-line given for selection gains.

The purpose of this study was to develop the <TEX>$PM_{2.5}$</TEX> source profiles for diesel and gasoline-powered vehicles, which contained mass abundances in terms fraction chemical species. Seven diesel-powered vehicles nine were sampled from a chassis dynamometer exhaust dilution system. species measured water-soluble ions, elements, elemental carbon (EC), organic (OC). From study, large EC (54.5%), OC (26.0%), <TEX>${SO_4}^{2-}$</TEX> (1.5%), <TEX>${NO_3}^-$</TEX> (0.8%), S (0.6%)...

Additive manufactured interlocking structures often face challenges in achieving suitable joinability due to thermal deformation. This issue becomes particularly interesting when fabricating that require high density but not fully connected layers, such as soft-magnetic materials. study focuses on systematical investigation of the deformation a function finger thickness and building direction model structure. In perpendicular build plate, distortions joint part were significantly reduced...

A study on the recovery of nickel from Fe-Ni alloy scrap was conducted using molten magnesium by dissolving only Ni component and then removing Mg vacuum distillation method. The recovering faction higher than 99% achieved at temperatures above 1,073 K 99.5% purity level successfully obtained under degree 10(-5) torr 1,273 K. purity, phase, rate were examined scanning electron microscopy, elemental analyser, X-ray diffraction.

In this study, design for additive manufacturing (DfAM) of release agent injection manifold hot forging has been performed to achieve weight reduction and flow path optimization. The 53.5% was achieved, thereby enabling the application stainless steel 316L, which high strength corrosion resistance. Lightweight manifolds using Al-Mg-10Si SUS316L materials were fabricated by PBF-type metal 3D printer. feasibility test showed that mold life improved 14% solving residual problem. addition,...

HigH-EfficiEncy cooling SyStEm USing AdditivE mAnUfActUringin this study, we propose a structure manufactured using specialized three-dimensional (3D) printing design method.A performance test system with complex geometry that used thermoelectric module was metal 3D printing.A model constructed by applying additive manufacturing simulation and computational fluid analysis techniques, the correlation between each element efficiency examined.in evaluation conducted base measurement system.The...

Using nanoindentation under various strain rates, the mechanical properties of a laser powder bed fusion (PBF) SKD61 at 800 mm/s scan speed were investigated and compared to PBF H13. No obvious pile-up due ratio residual depth (hf) maximum (hmax) being lower than 0.7 no cracking observed on any indenter surfaces. The strain-rate sensitivity (m) was found be 0.034, with hardness increasing from 8.65 GPa 9.93 as rate increased between 0.002 s−1 0.1 s−1. At same speed, m value H13 (m = 0.028)...

Crack formation due to columnar grains in precipitation-hardenable Al alloys such as Al–Zn–Cu–Mg limits the applicability of laser-based additive manufacturing. Recently, cracking has been effectively reduced by introducing equiaxed through inoculant addition alloy powder. However, mechanisms which can prevent have not explained from viewpoint both microstructure and process parameters. Thus, control over behavior during laser powder bed fusion (LPBF) remained limited because a lack...

In this study, the design for additive manufacturing of shoe molds with complex and precise patterns was performed to achieve rapid prototyping. Low alloy steels such as AISI4340 SAE1524 were selected make apply conventional chemical etching process. A lattice-oriented optimization toolpath tested reduce processing time. reduction 60% in time pattern precision 0.3 ㎜ been achieved. Moreover, improve reliability formation, single-layer image analysis computer vision machine learning developed...