Hybrid Cladding Research Articles

Continuous wave GaSb-based interband cascade lasers with hybrid cladding layers operated at room temperature and above

We report the preliminary demonstration of continuous wave (cw) GaSb-based interband cascade lasers (ICLs) with hybrid cladding layers at high temperatures up to 80 °C near a wavelength of 3.72 μm. These ICLs have narrow-ridge widths of 7–11 μm with improved thermal dissipation compared to broad-area devices. They delivered a cw output power of more than 30 mW/facet at 20 °C and had a cw threshold current density of 270 A/cm2 with a voltage efficiency of 78% at 300 K. The obtained voltage efficiency of 78% is the highest ever reported among cw GaSb-based ICLs at room temperature, indicating an advantage of efficient carrier transport in the ICL with the hybrid cladding layers. The dependence of device performance on the narrow-ridge width and cavity length was investigated. The results suggested ways to further improve future devices.

Comparison between InAs-based and GaSb-based interband cascade lasers with hybrid superlattice plasmon-enhanced claddings

We compare InAs-based and GaSb-based interband cascade lasers (ICLs) with the same 12-stage active region designed to emit at a wavelength of 4.6 µm. They employ a hybrid cladding architecture with the same geometry and inner claddings consisting of InAs/AlSb superlattices but different outer claddings: The InAs-based ICL employs plasmon enhanced n-type doped InAs layers while the GaSb-based ICL employs plasmon-enhanced n-type doped InAs0.915Sb0.085 claddings lattice matched to GaSb. Due to the lower refractive index of n + -InAsSb (n = 2.88) compared to n+ -InAs (n = 3.10) and higher refractive index of separate confinement layers, the GaSb-based ICL shows a 3.8% higher optical mode confinement in the active region compared to the InAs-based ICL. However, the InAs-based ICL has 15.3% lower free carrier absorption losses than the GaSb-based ICL, resulting in approximately equal threshold gains. Experimentally operated in pulsed mode and at room temperature, the GaSb-based ICL shows a 15.3% lower threshold current density, but also 12.8% higher threshold voltage resulting in comparable threshold power densities. Also presented is the influence of geometry and doping variation on confinement factors and calculated free carrier absorption losses in the GaSb-based ICL.

Enhancing high-temperature wear resistance of cladded Inconel 718 through hybrid of directed energy deposition with ultrasonic nano-crystal surface modification

We present an innovative method for achieving highly durable and finely controllable internal microstructures within cladded 718 layers utilizing a hybrid cladding approach. This process alternates between two methods: laser directed energy deposition in which four layers of Inconel 718 built up using a laser power of 350 W and a scanning speed of 800 mm/min, and ultrasonic nanocrystal surface modification (UNSM), applied to every fourth deposited surface at elevated temperatures of 300 and 600 °C, with a frequency of 20 kHz and an interval of 0.05 mm, respectively. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) are used to analyze the effect of grain refinement and concentrated dislocation distribution induced by the hybrid cladding. Through the employment of high temperature UNSM treatment between the cladded Inconel 718 layers, profound grain refinement and dislocation enhancement occur, significantly bolstering the wear resistance of the intermediate layer under high temperature conditions. We conducted thorough analyses, employing finite element analysis and experiments, to investigate the diverse temperature conditions of UNSM treatment and their impact on increasing the affected depth of UNSM treatment. Furthermore, we closely examined the changes in microstructure and mechanical properties within the remelted and UNSM-treated zone of the internal layers. Our study confirms that the high temperature hybrid cladding process, operating below 600 °C, resulted in a 27 % reduction in overall material wear-loss compared to conventional cladding methods. Notably, even in high temperature wear tests ranging from 200 to 800 °C, the proposed method significantly mitigated wear amounts in each case, indicating its potential to enhance the mechanical integrity of various components operating under elevated temperature conditions.

Design and analysis of low-loss and low-dispersion hybrid cladding tube antiresonant fiber for the THz regime

Design and analysis of low-loss and low-dispersion hybrid cladding tube antiresonant fiber for the THz regime

Integrating machine learning and parametric design for energy-efficient building cladding systems in arid climates: Sport hall in Kerman

Climate change, driven by fossil fuel dependence, presents a significant challenge for the construction industry, particularly in energy-intensive regions like arid climates. This research investigates the potential of integrating machine learning and parametric optimization to enhance the energy efficiency of spatial structure domes in such environments. Focusing on a sports pavilion in Kerman, Iran, the study examines the crucial role of cladding systems in building energy performance. Employing a rigorous four-phase methodology, the research optimizes dome cladding materials for hot, dry climates using a dual objective function: energy cost and material cost. The process involves a comprehensive literature review, data-driven material selection, advanced energy simulations, and optimization analysis. Parametric modeling tools (Rhino, Grasshopper, Honeybee) facilitate the comparative analysis of various cladding systems. Multivariate Polynomial Regression (MPR) enables predictive modeling of energy consumption and material costs, streamlining the design process for architects. The optimized solution is a hybrid cladding model composed of 10 % polycarbonate and 90 % aluminum. Analysis reveals that the hybrid system offers superior energy optimization compared to pure aluminum (4.58 %) and polycarbonate (5.70 %). While polycarbonate has a lower initial material cost, the hybrid system achieves a balance between material expenditure and long-term energy efficiency. This highlights the importance of considering life-cycle costs when evaluating building envelope materials. This research advances a framework that leverages machine learning and parametric design for building envelope optimization. This framework empowers architects and engineers to create energy-efficient structures within arid environments, promoting a more sustainable built environment.

A novel heterogeneous particle addition method based on laser cladding hybrid wire arc additive manufacturing: improvement performance of stainless steel components

ABSTRACT The direct preparation of large components by laser cladding (LC) is not economical, but if it is used as a means of trace element addition and combined with the high efficiency advantages of wire arc additive manufacturing (WAAM), efficient manufacturing and high degree of freedom design of components can be achieved. In this study, high toughness and high plasticity stainless steel components were successfully prepared by combining WAAM and LC. The microstructure in the hybrid deposited specimens evolved into a single austenite, and the proportion of cubic and {001}<100 > textures increased. The mechanical properties obtained were significantly greater than those recommended for use by ASTM A479. The toughness of the hybrid deposited specimens was significantly improved, with a maximum increase in yield strength of 32%, exceeding 350 MPa. The elongation increased by a maximum of 12.7%, reaching 89.2% in the horizontal direction.

Study on Microstructure and Mechanical Properties of AlCoCrFeNi High-Entropy Alloy Coating Prepared by Electroplating-Electron Beam Hybrid Cladding

Study on Microstructure and Mechanical Properties of AlCoCrFeNi High-Entropy Alloy Coating Prepared by Electroplating-Electron Beam Hybrid Cladding

Microstructure, high-temperature cyclic oxidation, and hot corrosion behaviors of Inconel 718 alloy produced by laser-induction hybrid cladding

The microstructure evolution, cyclic oxidation, and hot corrosion behavior of the unheated-treated (As-built) and solution + double aging (SDA)-treated Inconel 718 alloys fabricated through laser-induction hybrid cladding (LIHC) were investigated. It was found that the as-built Inconel 718 alloy exhibits a columnar dendritic with intergranular Laves phase. After SDA-treated, γ", γ′, δ and carbide phases precipitated, the Laves phase became fine and dispersed. After cyclic oxidation, the Cr2O3 scales were formed on both as-built and SDA-treated LIHC-produced Inconel 718 alloy, which could provide good cyclic oxidation resistance for the Inconel 718 alloy. However, the as-built and SDA-treated LIHC-produced Inconel 718 alloy suffered severe hot corrosion in 95 wt% Na2SO4 + 5 wt% NaCl mixed salt solution and many corrosion products were generated, including Cr2O3, NiCr2O4, NaNbO3, Na2CrO4, NiFe2O4, Fe3O4, and NiO. Nevertheless, the SDA-treated sample showed better cyclic oxidation and hot corrosion resistance than the as-built sample, owing to the more compact Cr2O3 scale.

GaSb-based interband cascade laser with hybrid superlattice plasmon-enhanced claddings

We present an interband cascade laser (ICL) emitting at 5.2 µm consisting of an 8-stage active region and a hybrid cladding composed of outer plasmon-enhanced InAs0.915Sb0.085 and inner InAs/AlSb superlattice claddings. The hybrid cladding architecture shows an increase in mode confinement in the active region by 11.2% according to the simulation. This is a consequence of a significantly lower refractive index of plasmon-enhanced claddings. The threshold current density is 242 A/cm2 in pulsed operation at room temperature. This is the lowest value reported to date for ICLs emitting at wavelengths longer than 5 µm. We also report close to record value threshold power density of 840 W/cm2 for ICLs at such wavelengths.

Porous core fiber with hybrid cladding for ultra-flattened dispersion and low loss propagation of terahertz waves

This work proposes a design of a porous-core photonic crystal fiber (PC-PCF) made of a cyclic olefin copolymer, Zeonex, with a hybrid cladding for low-loss terahertz (THz) wave transmission. A combination of circular and elliptical air holes is employed, resulting in a very low material absorption loss of 0.045 cm-1 at Dcore = 450 µm and f = 1 THz. A flat dispersion of 0.73 ± 0.13 ps/THz/cm is obtained for a broad frequency range of 0.5–1.4 THz. Core diameter and frequency response of other key features such as normalized frequency (V-parameter), confinement loss, effective area, nonlinearity and the percentage of the power flow through different sections of the proposed PC-PCF are also analyzed. Comparing to state-of-the-art, our design is superior in terms of loss, dispersion and power fraction. Our proposed design can be manufactured using the established extrusion process and be used for long distance low-loss Terahertz (THz) communication.

Microstructure, wear and friction behavior of CoCrAlTaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

Microstructure, wear and friction behavior of CoCrAlTaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

Improved device performance of interband cascade lasers with hybrid cladding layers operating in the 3–4 µm wavelength region

In this work, we briefly review the development and status of interband cascade lasers (ICLs) as related to long-standing issues due to the InAs/AlSb superlattice cladding. By focusing on a hybrid cladding approach to alleviate these issues, we demonstrate substantially improved device performance of ICLs compared to earlier reported ICLs of a similar design in the 3–4 µm wavelength region. These improvements include a threshold current density for broad-area devices as low as 134 A/cm2 at 300 K and reduced threshold voltage with a peak voltage efficiency of 80%, which is more than 10% higher than that obtained from previously reported ICLs. Moreover, we have demonstrated continuous wave (cw) operation of a broad-area device up to 278 K, the highest cw operating temperature among epi-side up mounted broad-area type-II ICLs, implying improved thermal dissipation with the hybrid cladding approach. Additionally, by conducting a comparative study of ICLs with different GaSb layer thicknesses in the hole injector, we reveal and discuss an interesting correlation between the carrier transport, threshold voltage, and hole-induced absorption loss, which may help to guide device optimization for operation in a targeted temperature range.

Investigation on the Ni60-WC composite coatings deposited by extreme-high-speed laser-induction hybrid cladding technology: Forming characteristics, microstructure and wear behaviors

In this work, Ni60-WC composite coatings with 35 wt% WC (Ni65-WC35), 50 wt% WC (Ni50-WC50) and 65 wt% WC (Ni35-WC65) were deposited by the extreme-high-speed laser-induction hybrid laser cladding technology (EH-LIHC), and the forming characteristics, microstructure, hardness and wear behaviors were investigated systematically. Results indicated that all the EH-LIHCed Ni60-WC coatings displayed low-roughness surfaces and even-distributed WC particles, where the dilution ratio and WC's heat-loss increased with the rise of induction heating temperature (T) and WC's content. Crack-free single-layer Ni60-WC coatings could be obtained at T ≥ 600 °C, whereas some micro-cracks were inevitably induced during the multi-layer depositions. The WC particles mainly presented the decomposition/ dissolution-diffusion, collapse-dissolution and decomposition/dissolution-precipitation heat damages, corresponding to the W-rich dendritic/wing-like/filamentary structures, dendritic facet structures and blocky facet structures on the metal matrix, respectively. Under both loading forces of F = 50 N and 80 N, the wear rates Ni60-WC composite coatings presented the order of Ni35-WC65 < Ni65-WC35 < Ni50-WC50. Spalling of the matrix, cracking and crushing of the WC particles were detected on all worn surfaces. The Ni35-WC65 coating possessed the highest contents of WC particles and facet carbides, making its damage threshold and wear resistance enhanced significantly. Nonetheless, the wear debris in Ni65-WC35 coating had formed a metal layer covering on the worn surface, helping to alleviate the damage of the beneath WC particles significantly, therefore it possessed lower wear rate than that of Ni50-WC50 coating.

Effect of temperature on the oxidation behavior of Al2O3 reinforced CoCrAlYTa coating by laser-induction hybrid cladding

The 2 wt% Al2O3 reinforced CoCrAlYTa coatings (referred to as 2Al2O3-CoCrAlYTa) were manufactured by laser-induction hybrid cladding. And the oxidation behavior of the coatings was investigated using a thermogravimetric analyzer (TGA) at different oxidation temperatures (950 °C, 1000 °C, 1100 °C, and 1200 °C) in an air atmosphere with a test time of 200 min. The composition and microstructure of the oxide scales formed at different temperatures were characterized and investigated. Additionally, the microstructure evolution of the coating, failure mechanism of the oxide scales, and elemental diffusion at the different temperatures were also discussed. It was found that after oxidation, Al depleted zones appeared in the 2Al2O3-CoCrAlYTa coatings. When oxidation temperature was 950 °C, fine-equiaxed oxide grains were formed on the coating. Moreover, at 950 °C, 1000 °C, and 1100 °C, the oxide scales were intact, and no large voids were found in the oxide scale/coating interface. As the temperature reached 1200 °C, the oxide scale formed on the surface of the coating became thicker and consisted of an outer layer of fine equiaxial crystals and an inner layer of coarse columnar crystals, and large voids developed at the oxide scale/coating interface, causing the oxide scales to delaminate from the coating.

Interfacial structures evolution at hetero interfaces in SiCf/SiC | Nb | SiCf/SiC sandwich cladding structure

The appropriate hetero interfacial structure between metal and ceramics is a challenging topic in materials science. In this paper, a sandwich hybrid cladding structure made of SiCf/SiC composite and refractory metal niobium (Nb) is designed for application in a lead-cooled fast reactor. A diffusion reactive interfacial layer composed of β-SiC | NbC | Nb5Si4C | α-Nb5Si3 | β-Nb2C | Nb between SiCf/SiC composite and Nb is experimentally validated after heat treatment in a simulating reactor environment. Moreover, Kirkendall voids are found at the interface between Nb5Si4C and Nb5Si3 sublayers when the annealing temperature is higher than 1500 °C. Lastly, the formation mechanisms of interfacial structures are revealed based on thermodynamics and kinetics, meanwhile the diffusion coefficients k at 1500 °C and activation energy are calculated to be 2.81 × 10−14 m2/s and 270 kJ/mol, respectively. This work provides a practical strategy for developing hybrid composites of metal/ceramic matrix composites.

Analytical Formulas for Micro-Bending and Surface Scattering Loss Estimation in Tube Lattice Fibers

Simple analytical formulas for micro-bending and surface scattering loss in Hollow-Core Tube Lattice Fibers are here proposed and numerically validated. They can also be applied to other Hollow-Core fibers with similar core-cladding interfaces such as Hybrid cladding Kagome-Tubular, Nested Tubes, and Kagome fibers. Scaling laws for both loss mechanisms are also given and discussed.

Comparison on the Ni60 Coatings Deposited by Extreme-High-Speed and Conventional Laser-Induction Hybrid Cladding Technologies: Forming Features, Microstructure and Wear Behaviors

Comparison on the Ni60 Coatings Deposited by Extreme-High-Speed and Conventional Laser-Induction Hybrid Cladding Technologies: Forming Features, Microstructure and Wear Behaviors

Long-distance modal power equalization with hybrid pumped FM-EDFA

In a few-mode fiber-based mode division multiplexing system, the different modes as distinct channels suffer from discrepant mode-dependent loss, leading to an intensive channel power imbalance and large bit error. The few-mode erbium-doped fiber amplifier (FM-EDFA) enables mode power regulation to ensure high-quality long-distance transmission. In this paper, we propose an FM-EDFA for long-haul equalization with a core and cladding hybrid pump structure. The particle swarm optimization is applied to determine the multilayered erbium ions doping profile. Based on the profile, targeted compensation for high-order modes with high loss is realized to mitigate the power difference in long-distance transmission. Compared with the single pump selection, the differential modal gain reduces from 6.553 dB to 1.239 dB in the hybrid pump with a 1000 km multistage amplification and transmission. We provide new ideas for loss compensation and power balance in long-distance transmission. This method has the ability of dynamic power adjustment while keeping the design simple.

A Hybrid Cladding Ring-Core Photonic Crystal Fibers for OAM Transmission with Weak Spin–Orbit Coupling and Strong Bending Resistance

A hybrid cladding ring-core photonic crystal fiber (PCF) for transmitting orbital angular momentum (OAM) modes is proposed, which breaks the circular symmetry of the fiber structure to suppress the spin–orbit coupling and promotes bending resistance. Through the optimization of fiber structure parameters, the designed fiber can support 22 OAM modes (6 OAM mode groups) over a 200-nm wide bandwidth (covering the whole C + L band) with large effective refractive index separation between adjacent modes (&gt;10−4) and mode groups (&gt;3.6 × 10−3), low confinement losses (&lt;3.5 × 10−9 dB/m), and high mode purity (&gt;98.3%). Meanwhile, the phase of the OAM modes varies periodically and uniformly with an increase in the azimuth angle, and the polarization of OAM modes maintain nearly circular polarization in the designed fiber, which also demonstrates that the fiber has weak spin–orbit coupling. Moreover, the confinement losses of all vector modes are less than 10−7 dB/m when the bending radius is larger than 0.8 mm, indicating strong bending resistance. Furthermore, the fiber also exhibits large differential group delay, relatively low and flat dispersion, and low nonlinear coefficients (&lt;2.0 W−1/km). Therefore, the novel fiber structure has great potential in the application of mode division multiplexing (MDM) based on OAM modes.

Higher wear-resistant surfacing at high temperatures using a hybrid cladding process

A novel hybrid cladding process is developed to control the mechanical properties of the inner metallic clad layer by combining direct energy deposition (DED) and ultrasonic nanocrystal surface modification (UNSM). The hybrid process allows the manipulation of the cladding layers' internal and external mechanical properties to the desired surface and bulk properties. To verify the usefulness of this method, the wear resistance test of the Inconel-718 cladding layer at high temperatures of 200 and 400 °C was performed, and it was confirmed that the wear resistance was improved to 25.4 % and 14.4 %, respectively. This work analyzes the wear-resistant characteristics with and without UNSM treatment in the DED process. The proposed method is a promising way to change the internal mechanical properties of the cladding layer with high controllability and repeatability.