Metal Printing Research Articles

Distance-controlled direct ink writing of titanium alloy with enhanced shape diversity and controllable porosity

Porous titanium alloys have been extensively used for diverse engineering applications. However, current additive manufacturing (AM) strategies face significant challenges (e.g., low fabrication efficiency and limited shape diversity) in producing porous titanium alloys. This work aims to develop a distance-controlled direct ink writing (DC-DIW) approach for constructing macroscale 3D architectures from titanium alloy powders. This approach integrates a constant interlayer distance control with traditional DIW, breaking through the angle limit in current porous metal printing from 60° to 30°. Additionally, subsequent heat treatment is applied to control microstructures. To demonstrate the capabilities of this approach, three representative structures, including a bifurcated tube, an orbital implant, and a knee implant, are successfully printed and treated, achieving suitable mechanical properties and high shape fidelity. This work provides a viable and efficient AM strategy for fabricating porous titanium alloys with enhanced shape diversity and controllable porosity suitable for various engineering applications.

Clinical Outcomes of Novel CAD/CAM-Designed Functional Space Maintainers Produced via Additive and Subtractive Methods: A randomized controlled trial.

Since passive fixed space maintainers do not restore the lost tooth or provide chewing function, this study seeks to assess the effectiveness of an innovative approach for maintaining space following the premature extraction of first primary molars, utilizing functional space maintainers designed with CAD/CAM. This randomized controlled trial included 28 patients into two groups, 15 in 3D Print and 13 in Milling. The inclusion criteria required extraction or loss of the first primary molar due to complications of caries, with a prolonged period until eruption of the successor. Space maintainers were fabricated using 3D printing metal (Co 69%, Cr 25%, W 9.5%, Mo 3.5%, Si 1%, Scheftner, Germany) and milling composite (breCAM.HIPC, Bredent, Germany). This study evaluated the efficiency of space maintainers through clinical check-ups at one, three, and six months, maximum occlusal bite force, and masticatory performance assessments. A positive clinical trend was noted over time, with the "type of space maintainer" factor (Milling vs. 3D Print) influencing the degree of clinical assessment (p < 0.001). There were no significant differences in maximum occlusal bite force between sides for both types of space maintainers (p = 0.270 for 3D Print and p = 0.765 for Milling). Significant improvements were observed in masticatory performance after the placement of both types of space maintainers. A six-month follow-up showed that 3D-printed metal outperformed milled composite ones, with no significant differences in bite force or masticatory performance, indicating that CAD/CAM technology could set new standards in producing functional space maintainers. This study underscores the potential of these technologies to set new standards in pediatric dentistry, particularly for maintaining space following premature tooth loss, while ensuring improved functional outcomes for young patients.

Parameter Design in Production by Means of Robust Fuzzed PMOO in Case of Desirable Target

A proper parameter design in the production process is critical to guarantee the quality of products and their improvement. The rationality of the previous traditional approaches for robust assessment including the Taguchi method and dual response method is questionable. In this article, the combination of probabilistic multi-objective optimization (PMOO) with membership approach in fuzzy theory is developed to conduct parameter design of production in case of desirable target with robustness deeply, which is furthermore applied to two examples of both parametric design of gas metal arc (GMA) welding process and printing machine's ability. In the new approach, the mean value of "complement" of membership value of a set of test data belonging to its desired target of an objective response is taken as one sub-objective response, which is an unbeneficial type of index in the assessment to contribute the first part of the partial preferable probability of the objective. In contrast, the dispersion of a set of test data in terms of membership with respect to the desired target value is taken as the other sub-objective response to contribute the second part of the partial preferable probability of the objective simultaneously, which is an unbeneficial index. Thus, the fuzzed PMOO approach is regulated comprehensively. Besides, the consequences of application examples reflect the reasonability of the approach as an auxiliary measure for PMOO consistently to perform optimal robust design.

Progress in the Development of Additive Manufacturing Techniques for Infrastructure Engineering

: It is a moral duty to act in a way that considers the welfare of both people and the planet. When constructing, two factors should be considered: the sustainability of the developmentrelated workforce and the state of the world after construction. Many experts have achieved notable reforms in the civil infrastructure systems (CIS) sector in the past. However, additive manufacturing (AM) does not seem to be properly understood by the CIS business. This survey examines how all the fundamental components used by AM in CIS, such as metals, cement, and polymers, are utilized. The goal of this study is to foster AM innovation, particularly in the CIS, and to provide an overview of AM development from 2011 to 2022. Additionally, the various AM techniques used to construct the aforementioned structures are presented. The audit research suggests that AM might be beneficial in the CIS industry due to the fact that residences, additions, and seats were constructed using this technique. Photos of the constructed structures are also included to enhance the reader's understanding. It is generally assumed that implementing AM tactics in the CIS industry may reduce material consumption, expedite the development process, and enhance employee safety. Due to the limited amount of available research, further investigation into polymer printing and metal printing is recommended.

Additive metal printing on multi materials using an atmospheric pressure plasma jet on a 5-Axis platform

Additive metal printing on multi materials using an atmospheric pressure plasma jet on a 5-Axis platform

Расчет температурных полей на основе конечно-элементной модели процесса аддитивного синтеза изделия

The work is devoted to the creation of a hybrid finite element model of the process of additive synthesis of a product by the Wire Arc Additive Manufacturing/3D Metal Print method, supplemented by a block of wave strain hardening of the synthesized product. The main result obtained is the proposed original approach to the mathematical modeling of fundamentally new processes of synthesis and hardening of a wide range of products manufactured from various materials in the form of wire, which can be extended to the entire class of additive synthesis processes with periodic or post-processing. The main feature of the approach is the hybridization of calculation models, while, unlike known solutions, significant attention is paid to the processes of exchange and transmission of information between the models of synthesis and hardening processes. A distinctive feature of the hybrid model is the need for a periodic exchange of information on the geometric and temperature parameters of the synthesized areas at a specific point in time. The novelty of the hybrid model is in the application of coordinated approaches to solving thermal and mechanical problems in a three-dimensional formulation in the ANSYS environment, taking into account the natural dynamic heat flows that form in the synthesized product and the installation table modeled by the finite element method. Calculation of continuously changing dynamic temperature fields in the synthesized product with additional optimization and visualization capabilities is an important structural part of the model. The studies performed allowed us to identify a significant range of the ratio of the product and table volumes 30 ≤ Vс/Vи ≤ 100 and patterns in the formation of temperature fields when changing the table parameters.

Advancements and Challenges in Wire Arc Additive Manufacturing – A Review

Wire arc additive manufacturing (WAAM) is a groundbreaking advancement in 3D metal printing, enabling efficient and cost-effective production of large, complex components using gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW). Suitable for metals like stainless steel, aluminium, and titanium alloys, WAAM involves layer-by-layer deposition of molten metal using an electric arc to melt wire feedstock. Despite its benefits, WAAM faces challenges with thermal cycles and microstructural inconsistencies, affecting component strength and ductility. Recent studies focus on microstructural analysis and mechanical properties, revealing varied microstructures due to distinct heat cycles. Research indicates consistent hardness across WAAM-fabricated components, with variations based on microstructural constituents. Optimizing the WAAM process involves understanding these characteristics and refining welding parameters. Advances in WAAM technology promise significant improvements in manufacturing efficiency, cost-effectiveness, and component quality across various industries.

3D Metal printed compact high‐Q bandpass filter using folded groove gap waveguide resonator with modified nails

AbstractThis paper first presented a novel kind of modified curved nails for building the gap waveguide. By controlling the curved degrees, the realized gap waveguide can achieve a wider electromagnetic band gap range. Subsequently, a groove gap waveguide resonator based on this was proposed that can offer the advantages of miniaturization and high unloaded quality (Qu) values, which is a good candidate for designing low‐loss filters. To further reduce the footprints while maintaining the high Qu, the concept of the folded waveguide was deployed here to construct the so‐called folded groove gap waveguide resonator for the first time. Then, a 4‐pole filter based on the folded groove gap waveguide resonator was designed to validate the possibilities. The designed filter showed comparable performance as its counterparts of half‐mode gap waveguide resonator but with smaller. For rapid prototyping, 3D metal printing was adopted to fabricate the filter concerning its periodical nail structures. The printing quality is acceptable, and the tested results agreed well with the simulated ones.

Study on mechanical properties of deposited metallic objects for different build strategies using semi-automatic welding setup

Gas metal arc welding-based metal printing is an effective tool to fabricate complex prototypes and tangibles products having enormous advantages such as low cost and minimum lead time for widespread engineering applications in the developed industry. Gas metal arc welding-based metal-deposition was implemented to build three dimensional specimens with varying cross-sections through different paths strategies, that is, spiral-in (circular and square) and raster (square, diagonal and circular). The given trajectory was followed by providing programmed inputs to the controller of the setup to deposit metal layer over the layer for producing a positive slope on the lower half and a negative slope on the upper half section of the deposited object. The fabricated setup can be used to produce sloped objects having 20° inclination. The mechanical properties such as tensile strength, bending strength and microhardness of the deposited 3D parts were investigated to observe the effect of different depositing strategies. Amongst the various deposition strategies adopted to build parts, the raster diagonal (square) and raster linear (circular) showed the maximum value of tensile and bending strength. The microstructural characterization of the deposited parts was also carried out using scanning electron microscopy (SEM).

Kinetic liquid metal synthesis of flexible 2D conductive oxides for multimodal wearable sensing

Transparent conducting oxides (TCOs) are crucial for high-performance displays, solar cells, and wearable sensors. However, their high process temperatures and brittle nature have hindered their use in flexible electronics. In this paper, we overturn these limitations by harnessing Cabrera-Mott oxidation to fabricate large-area, two-dimensional (2D) transparent electrodes via liquid metal printing. Our robotic, vacuum-free process deposits ultrathin (2–10 nm) indium tin oxide (ITO) with exceptional flexibility, transparency (>95%) and conductivity (>1300 S/cm) by utilizing hypoeutectic In-Sn alloys to print at <140 °C. Detailed characterization reveals the efficacy of Sn-doping and high crystallinity with large, platelike grains. The ultrathin nature enhances bending strain tolerance and scratch resistance, exceeding durability of PEDOT and offering low contact impedance to skin comparable to Ag/AgCl. We implement 2D ITO in synchronous, multimodal electrocardiography (ECG) and pulse plethysmography (PPG) measurements. This order-of-magnitude improvement to printed TCOs could enable wearable biometrics and display-integrated sensors.

Investigating the Suitability of Printing Metal Current Collectors Directly Onto the GDMs of PEMFCs

Flexible electrochemical energy sources with unconventional cell materials and topologies are becoming more and more popular because they present novel design possibilities that are currently being investigated. Adopting electronics manufacturing techniques to manufacture flexible electrochemical devices can provide advantages such as conformability, high power density, high specific power, and lower costs. This study examines the feasibility of printing metal current collectors (CCs) directly onto Gas Diffusion Medium (GDM) typically used in Proton Exchange Membrane Fuel Cells (PEMFCs). In this work, we print the metal CCs directly onto the GDM using different techniques such as screen printing and ink jet printing. We also investigate the effect of varying the metal CCs geometry (square shape vs. hexagonal), opening ratio (30%, 40% and 50%) and metal thicknesses (10 µm to 50 µm thick) on the overall single cell performance and cell ohmic resistances. Techniques used to understand cell performance include I-V polarization curves, electrochemical impedance spectroscopy (EIS), and thermal imaging. The performance of the cells tested with the embedded GDM/Metal CCs is compared to the performance of a standard cell.

Ultrathin Gallium Oxide As a Gate Dielectric and Passivation Layer for Two-Dimensional Devices with Conductive Filament Contacts

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are generally regarded as the channel material for post-silicon nanoelectronics owing to their distinctive crystal structure consisting of atomically thin dangling-bond-free layers, tunable bandgap and high carrier mobility. However, 2D devices based on TMDs typically suffer from performance degradation due to unwanted atmospheric reactions or adsorbates and require surface passivation to ensure that device performance is maintained. Recently, ultrathin metal oxides obtained through liquid metal printing or squeezing technique have emerged as a new class of 2D material with nanometer-scale thickness and large-area uniformity. Among them, ultrathin amorphous gallium oxide (GaOX) has garnered significant attention for its ease of fabrication owing to the low melting point of gallium (29.76 °C), large bandgap, and unique insulating and passivating properties. The ultrathin GaOX has been utilized for large-area passivation of 2D materials and as a dielectric for wide bandgap semiconductor devices. However, the integration of the ultrathin GaOX with 2D devices based on TMDs has rarely been investigated. In this study, we fabricated 2D devices based on multilayer n-type tungsten disulfide (WS2), wholly enveloped by the ultrathin GaOX. The ultrathin GaOX served as a dielectric passivation layer in the gate and channel region, whereas conductive filaments (CFs) were created in the ultrathin GaOX in the contact region through electroforming to form electrical contacts to the passivated WS2.The WS2 multilayers for the channel were mechanically exfoliated from its bulk crystal and were aligned to and dry-transferred onto pre-patterned Ti/Pt bottom electrodes on Si/SiO2 substrates. Liquid gallium droplets were placed on prepared polydimethylsiloxane (PDMS)/polypropylene carbonate (PPC) films and were firmly compressed using a PDMS film supported on a glass slide to produce ultrathin GaOX monolayers. The fabricated ultrathin GaOX monolayers were dry-transferred onto the prepared WS2 channels by utilizing the PPC film as a sacrificial layer. The ultrathin GaOX monolayers were slowly lowered to fully contact the prepared substrates, after which the substrates were heated to 90 °C to soften and release the PPC films from the PDMS films. The PPC films held down the ultrathin GaOX monolayers on the substrates during the detachment of the PDMS films and were removed later by immersion in acetone. This process was repeated twice to form the ultrathin GaOX bilayers on the WS2 channels. Ti/Au drain and source top electrodes were formed above the Ti/Pt bottom electrodes before Ni/Au top-gate electrodes were formed to finalize the WS2/GaOX field-effect transistors (FETs). CF contacts to the drain and source region of the passivated WS2 channels were created via electroforming, where positive and negative bias voltages were applied to the top electrodes with the corresponding bottom electrodes grounded.The ultrathin GaOX monolayer (~4.7 nm) and bilayer (~10.1 nm) fabricated in this work were determined to be highly uniform with root-mean-square roughness of 0.45–0.57 nm using atomic force microscopy. The ultrathin GaOX bilayer was evaluated via X-ray photoelectron spectroscopy to have an oxygen-deficient chemical composition with a sub-stoichiometric Ga:O ratio of 42:58 (Ga2O2.8). From the capacitance–voltage and current–voltage analyses of Pt/GaOX/graphene metal–insulator–metal devices, dielectric constant of 3.1 and dielectric breakdown voltage of +8 V were extracted for the ultrathin GaOX bilayer, respectively. The electroforming process of the ultrathin GaOX bilayer in the contact region of the WS2/GaOX FETs was irreversible, only showing decrease in the resistance during consecutive sweeps regardless of the polarity of the applied bias voltages. After the CF formation in ultrathin GaOX bilayers in the contact region, the electrical properties of WS2/GaOX FETs were investigated. The devices exhibited excellent top-gated performance with low subthreshold swing of 68.0–84.6 mV/dec and minimal hysteresis of 0.10–0.12 V. Furthermore, the CF contacts and the devices exhibited great electrical stability even after 50 days. Also, dual-gate logic operations of AND gate and OR gate were demonstrated using both the top and back gates of the WS2/GaOX FETs. This study demonstrates the implementation of the ultrathin GaOX as a gate dielectric, a passivation layer, and a CF contact layer in a single 2D device structure. The WS2/GaOX FETs exhibited outstanding electrical characteristics and stability, indicating the successful implementation and the versatility of the ultrathin GaOX. These results indicate the potential of the ultrathin GaOX as a key component in future 2D electronics.

Tailoring Heat and Mass Transfer for Next Generation of PEM Fuel Cells

The distribution of operating parameters inside PEM fuel cells under dynamic operating conditions is non-uniform. Designing operating conditions using constant Pt loading and temperature seems to result in a high number of problems for operation due to non-optimized heat and mass transfer. During operation using humidified reactants, large quantities of liquid water are accumulated inside the cell in porous layers and for this reason, it is very difficult to achieve high current densities without purging the cell which results in large waste of hydrogen fuel. If the reactants are not fully humidified, during operation at constant operating temperature, the ionomer in membrane and catalyst layers is prone to dehydration and starvation. By using a spatially variable temperature profile, i.e. variable temperature flow field, it is possible to achieve a delicate balance between the rate of produced water and water vapor partial pressure in such a manner as to achieve fully humidified conditions along the entire active area of the cell without the necessity for external humidification. This concept was studied using a combination of computational fluid dynamics and experimental research and it was shown that the application of a variable temperature flow field can be achieved using liquid coolant with a sufficiently low flow rate which is gradually heated up during the flow through the cell by utilizing the heat generated by the cell for establishing and maintaining the desired temperature profile. This concept was further improved by using a variable temperature profile in conjunction with a graded catalyst design. An experimental and numerical study was conducted to determine the optimal combination of variable temperature and graded Pt loading in the cathode catalyst which will show the highest performance. By comparing the optimal design with variable temperature and graded catalyst vs. isothermal operation with uniform catalyst loading, it was found that the performance can be dramatically increased. The operating current density at 0.6 V for the optimal case was 260% higher while Pt utilization was 19% lower when compared to the baseline isothermal constant catalyst loading case with notably enhanced current density distribution. To further enhance the performance we have designed and optimized novel flow fields with secondary channels for water removal near the cathode outlet using 3D metal printing and the results have shown that it is possible to achieve higher current densities with this simple flow field modification. Our investigation of the novel flow fields also included biomimetic design where we based our flow field on the design of shark skin, which was manufactured using a high-end milling machine with vibration compensation. This novel design utilizes inertial effects in the diffusion layers due to high flow velocities which is a novelty for PEM fuel cells since the flow velocities are commonly in a laminar regime. Utilization of these different new concepts has shown that it is possible to significantly enhance the performance of PEM fuel cells with combined numerical and experimental efforts and elucidates the direction of the research toward the development of tailored anisotropic heat and mass transfer for the next generation of fuel cells with improved performance and durability.Funding: This work has been supported by the Croatian Science Foundation under the project IP.2020-02-6249. Figure 1

Cold spray additive manufacturing metal knitting: Process parameters effect on aluminum components geometry

As cold spray (CS) has evolved into a 3D printing method, known as CS additive manufacturing (CSAM), new challenges have emerged: geometry accuracy, materials properties, and operation costs. This research is at the forefront of addressing these challenges, particularly focusing on the innovative approach of the new CSAM metal knitting (MK) strategy parameters. This approach influences the morphology of thin, straight walls and the deposit microstructure, hardness, strength, and abrasion wear. It was evaluated that a heat treatment (HT) of the CSAM MK deposits increased the tensile strength up to 300 % and reached a hardness close to 50 HV0.3. Regarding the costs, this work deposits an inexpensive irregular pure Al powder instead of the expensive gas atomized spherical ones seen for many AM processing. This work presents how the CSAM MK can be optimized for a high deposit geometry accuracy and control, as well as how a simple HT can overtake the CSAM MK cons of high porosity and lower cohesion of particles. Besides that, using a low-cost feedstock powder is one more attractive for the CSAM use for 3D printing of metals.

Clinical Acceptance of Digitally Produced Zirconia and Metal Post and Cores, Based on the Impression Method.

The existing literature predominantly examines post and core assessments post-cementation, neglecting the critical pre-cementation phase. Research on the clinical acceptance of dental posts received from dental laboratories before cementation is notably lacking. This study investigates the percentage of zirconia and metal dental posts that are deemed suitable for cementation by clinicians, among the total received from the dental laboratory. Additionally, it aims to examine whether this percentage varies based on the type of impression made by the clinician: digital impression versus conventional impression. This article introduces the application of computer-aided design-computer-aided manufacturing (CAD-CAM) technology for manufacturing customized zirconia and Cobalt-Chromium (Co-Cr) post and cores. Intraoral scanning is employed to capture the canal anatomy. In contrast to the traditional casting process, a three-dimensional (3D) metal printer machine is utilized to 3D print the metal post and core from Co-Cr, resulting in enhanced toughness and superior adaptability to the canal. Two null hypotheses were formulated, investigating the clinical acceptance of zirconia and metal posts obtained through traditional versus digital impressions. Among 577 post and cores, 95% of metal posts from both impression methods received clinical approval. However, for zirconia posts, a significantly higher acceptance rate (95% versus 88%) was observed for those from traditional impressions. The Chi-squared test yielded a p-value < 0.05, underscoring the clinical superiority of conventionally obtained zirconia posts and supporting the null hypothesis for metal posts. A significantly higher acceptance rate is apparent among zirconia post and cores manufactured through conventional impressions, in contrast to zirconia post and cores produced via digital impressions. No statistically significant difference was identified between metal post and cores obtained through digital impressions and those acquired through conventional impressions.

Learning Based Toolpath Planner on Diverse Graphs for 3D Printing

This paper presents a learning based planner for computing optimized 3D printing toolpaths on prescribed graphs, the challenges of which include the varying graph structures on different models and the large scale of nodes &amp; edges on a graph. We adopt an on-the-fly strategy to tackle these challenges, formulating the planner as a Deep Q-Network (DQN) based optimizer to decide the next 'best' node to visit. We construct the state spaces by the Local Search Graph (LSG) centered at different nodes on a graph, which is encoded by a carefully designed algorithm so that LSGs in similar configurations can be identified to re-use the earlier learned DQN priors for accelerating the computation of toolpath planning. Our method can cover different 3D printing applications by defining their corresponding reward functions. Toolpath planning problems in wire-frame printing, continuous fiber printing, and metallic printing are selected to demonstrate its generality. The performance of our planner has been verified by testing the resultant toolpaths in physical experiments. By using our planner, wire-frame models with up to 4.2k struts can be successfully printed, up to 93.3% of sharp turns on continuous fiber toolpaths can be avoided, and the thermal distortion in metallic printing can be reduced by 24.9%.

Self-adjusting voxelated electrochemical three-dimensional printing of metallic microstructures

Abstract Microscale metallic structures enhanced by additive manufacturing technology have attracted extensive attention especially in microelectronics and electromechanical devices. Meniscus-confined electrodeposition (MCED) advances microscale 3D metal printing, enabling simpler fabrication of superior metallic microstructures in air without complex equipment or post-processing. However, accurately predicting growth rates with current MCED techniques remain challenging, which is essential for precise structure fabrication and preventing nozzle clogging. In this work, we present a novel approach to electrochemical 3D printing that utilizes a self-adjusting, voxelated method for fabricating metallic microstructures. Diverging from conventional voxelated printing which focuses on monitoring voxel thickness for structure control, this technique adopts a holistic strategy. It ensures each voxel’s position is in alignment with the final structure by synchronizing the micropipette’s trajectory during deposition with the intended design, thus facilitating self-regulation of voxel position and reducing errors associated with environmental fluctuations in deposition parameters. The method’s ability to print micropillars with various tilt angles, high density, and helical arrays demonstrates its refined control over the deposition process. Transmission electron microscopy analysis reveals that the deposited structures, which are fabricated through layer-by-layer (voxel) printing, contain nanotwins that are widely known to enhance the material’s mechanical and electrical properties. Correspondingly, in situ scanning electron microscopy (SEM) microcompression tests confirm this enhancement, showing these structures exhibit a compressive yield strength exceeding 1 GPa. The indentation tests provided an average hardness of 3.71 GPa, which is the highest value reported in previous work using MCED. The resistivity measured by the four-point probe method was (1.95 ± 0.01) × 10−7 Ω·m, nearly 11 times that of bulk copper. These findings demonstrate the considerable advantage of this technique in fabricating complex metallic microstructures with enhanced mechanical properties, making it suitable for advanced applications in microsensors, microelectronics, and micro-electromechanical systems.

Sejarah Perkembangan Penulisan Al-Qur’an dan Tafsir di Indonesia

After the Conference of Ulama Al-Qur'an in 1984 and the Decree of the Minister of Religion number 25, it was agreed that the copying of the Al-Qur'an standardized using Ratsm Usmani. The initial emergence of Indonesian standard Mushaf Al-Qur'an cannot be separated from the existence of "Lajnah Pentashih Mushaf Al-Qur'an" which in the 1970's was under the Indonesian Ministry of Religion. However, if look at previous history, the copying of Al-Qur'an was carried out by various levels of society, including Ulama, Santri, or profesional copyists with interest for teaching purposes. So, before Lajnah was established, several regions had classic mushaf with their own characteristics. This research is intended to describe the development of Al Qur'an writting and its interpretation in Indonesia. The aim of this research is to describe the development of Al Qur'an writing. The approach used in this research is a library research approach, which utilizes library sources such as books, scientific journals, ar,ticles and reports. The results of this research show that the development of Al-Qur'an writing in Indonesia is generally divided into two major categories. Some were copied by rasm Usmani and the others with a combination of rasm imlai. This is shows that the traces of the Ottoman Empire in copying the Al Qur'an in the Nusantara were at least known, even though there were no written works that could explain it. As time progressed, the tradition of Al-Quran writing in mushaf (handwritten) form began to innovate with the emergence of various offers in the matter of copying mushaf, including lithography (stone printing), hypography (metal printing)

Surface Quality as a Factor Affecting the Functionality of Products Manufactured with Metal and 3D Printing Technologies.

Surface engineering is one of the most extensive industries. Virtually all areas of the economy benefit from the achievements of surface engineering. Surface quality affects the quality of finished products as well as the quality of manufactured parts. It affects both functional qualities and esthetics. Surface quality affects the image and reputation of a brand. This is particularly true for cars and household appliances. Surface modification of products is also aimed at improving their functional and protective properties. This applies to surfaces for producing hydrophobic surfaces, anti-wear protection of friction pairs, corrosion protection, and others. Metal technologies and 3D printing benefit from surface technologies that improve their functionality and facilitate the operation of products. Surface engineering offers a range of different coating and layering methods from varnishing and painting to sophisticated nanometric coatings. This paper presents an overview of selected surface engineering issues pertaining to metal products, with a particular focus on surface modification of products manufactured by 3D printing technology. It evaluates the impact of the surface quality of products on their functional and performance qualities.

Hypoeutectic Liquid Metal Printing of 2D Indium Gallium Oxide Transistors.

2D native surface oxides formed on low melting temperature metals such as indium and gallium offer unique opportunities for fabricating high-performance flexible electronics and optoelectronics based on a new class of liquid metal printing (LMP). An inherent property of these Cabrera-Mott 2D oxides is their suboxide nature (e.g., In2O3-x), which leads high mobility LMP semiconductors to exhibit high electron concentrations (ne >1019cm-3) limiting electrostatic control. Binary alloying of the molten precursor can produce doped, ternary metal oxides such as In-X-O with enhanced electronic performance and greater bias-stress stability, though this approach demands a deeper understanding of the native oxides of alloys. This work presents an approach for hypoeutectic rapid LMP of crystalline InGaOx (IGO) at ultralow process temperatures (180°C) beyond the state of the art to fabricate transistors with 10X steeper subthreshold slope and high mobility (≈18cm2Vs-1). Detailed characterization of IGO crystallinity, composition, and morphology, as well as measurements of its electronic density of states (DOS), show the impact of Ga-doping and reveal the limits of doping induced amorphization from hypoeutectic precursors. The ultralow process temperatures and compatibility with high-k Al2O3 dielectrics shown here indicate potential for 2D IGO to drive low-power flexible transparent electronics.