A5085944876- High-Temperature Coating Behaviors
- High Entropy Alloys Studies
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Additive Manufacturing Materials and Processes
- Mechanical Behavior of Composites
- Metal Alloys Wear and Properties
- Asymmetric Synthesis and Catalysis
- Silicon and Solar Cell Technologies
- Semiconductor materials and interfaces
- Surface Roughness and Optical Measurements
- Adhesion, Friction, and Surface Interactions
- Tribology and Wear Analysis
- Additive Manufacturing and 3D Printing Technologies
- Thin-Film Transistor Technologies
- Material Properties and Applications
- Advanced Surface Polishing Techniques
- Diamond and Carbon-based Materials Research
- Chemical Synthesis and Analysis
- Catalytic C–H Functionalization Methods
- Hydrogen embrittlement and corrosion behaviors in metals
- Nuclear Materials and Properties
- Laser Material Processing Techniques
- Catalytic Processes in Materials Science
- Astronomical Observations and Instrumentation
Chemnitz University of Technology
2015-2024
GlobalFoundries (Germany)
2020
Portland State University
2016-2017
University of British Columbia
2009
Saarland University
2004-2005
The investigation of high-entropy alloys (HEAs) has revealed many promising properties. HEAs with a high share Al and Ti are suitable for the formation lightweight materials. Investigations alloy system AlCoCrFeNiTi showed strength, hardness, ductility, wear resistance, which makes this special interesting surface engineering particularly thermal spray technology. In study, suitability inert gas-atomised HEA powder high-velocity-oxygen-fuel (HVOF) is investigated. This process allows...
The novel alloying concept of high-entropy alloys (HEAs) has been the focus many recent investigations revealing an interesting combination properties. Alloying with aluminium and titanium showed strong influence on microstructure phase composition. However, detailed are lacking. In this study, in alloy system AlCoCrFeNiTix was studied a wide range (molar ratios x = 0.0; 0.2; 0.5; 0.8; 1.0; 1.5). Detailed studies investigating microstructure, chemical composition, solidification behaviour,...
A new degradation mechanism (LeTID, Light and elevated Temperature Induced Degradation) for multicrystalline solar cells is presented. The reaches relative power losses of up to 10% on a time scale several hundreds hours carrier injection at field relevant temperatures. LeTID leads highly dependent lifetime characteristic after features regeneration phase. Characteristics as function temperature level are presented comparison between laboratory outdoor tests drawn. significantly reduced by...
Abstract High-entropy alloys (HEAs) represent an innovative development approach for new alloy systems. These materials have been found to yield promising properties, such as high strength in combination with sufficient ductility well wear and corrosion resistance. Especially a body-centered cubic (bcc) structure, advantageous surface properties revealed. However, typical HEA systems contain contents of expensive or scarce elements. Consequently, applying them coatings where their use is...
High‐entropy alloy AlCrFeCoNi powder with a metastable body centered cubic (bcc) structure is produced by inert gas atomization. This state largely preserved after processing the high‐velocity‐oxygen‐fuel (HVOF) thermal spraying. A heat treatment conducted objective to form duplex comprising ductile face (fcc) phase. The formation of an additional fcc phase accompanied decrease in hardness and significant improvement wear resistance. alternative route, spark plasma sintering (SPS), causes...
Abstract High-entropy alloys (HEAs) represent a relatively new group of multicomponent that have shown great potential for applications requiring tribological and oxidation resistant properties. Consequently, thermally sprayed coatings different HEA chemistries received increasing research attention. In this paper, atomized equimolar CrFeCoNi AlCrFeCoNi feedstocks were used high velocity air-fuel spraying (HVAF) to produce overlay using two nozzle configurations. The microstructure, phase...
High Entropy Alloys (HEA) are gaining increasing interest due to their unique combination of properties. Especially the high mechanical strength and hardness with distinct ductility makes them attractive for numerous applications. One interesting alloy system that exhibits excellent properties in bulk state is AlCoCrFeNiTi. A strength, wear resistance high-temperature necessary requirements application surface engineering. The suitability blended, mechanically ball milled inert gas atomized...
In this study, the wear behaviour of a powder metallurgically produced AlCoCrFeNiTi0.5 high-entropy alloy (HEAs) is investigated at elevated temperatures. Spark plasma sintering (SPS) inert gas atomised feedstock enables production dense bulk material. The microstructure evolution and phase formation are analysed. high cooling rate in atomisation process results spherical with comprising two finely distributed body-centred cubic phases. An additional complex crystal structure precipitates...
Abstract Eutectic high-entropy alloys (EHEAs) with a fine-lamellar structure and homogenous property profile are of particular interest for wear corrosion protection coatings. High cooling rates in the laser metal deposition (LMD) process can induce microstructure refinement allow formation supersaturated solid solution EHEAs. A subsequent annealing create equilibrium state. In present study, LMD coatings an ultrafine-grained Widmanstätten were produced from EHEA Al 0.3 CoCrFeNiMo 0.75 gas...
We have used the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) high-energy gamma-ray detector to look for fast blue-green laser pulses from vicinity of 187 stars. The STACEE offers unprecedented light-collecting capability detection nanosecond such lasers. estimate STACEE's sensitivity be approximately 10 photons/m2 at a wavelength 420 nm. stars been chosen because their characteristics are that they may harbor habitable planets, and relatively close Earth. Each star was...
Alloying aluminum offers the possibility of creating low-density high-entropy alloys (HEAs). Several studies that focus on system AlCoCrFeNiTi differ in their phase determination. The effect composition and microstructure compositionally complex alloy (CCA) AlxCoCrFeNiTi was studied with variation content (molar ratios x = 0.2, 0.8, 1.5). chemical elemental segregation measured for different domains microstructure. crystal structure determined using X-ray diffraction (XRD) analysis. To...
The surface hardening of single-face-centred cubic (fcc)-phase CrMnFeCoNi and the manganese-free CrFeCoNi alloy was conducted using low-temperature nitrocarburisation. microstructural investigations reveal successful formation a homogeneous diffusion layer with thickness approximately 16 µm. interstitial solution carbon nitrogen causes an anisotropic lattice expansion. increase in microhardness is accordance to graded concentration profile elements. Wear tests show significantly enhanced...
Mechanical interlocking has been proven to be an effective bonding mechanism for dissimilar material groups like polymers and metals. Therefore, this contribution assesses several surface pretreatments the metallic adherent. Blasting, etching, combined blasting thermal spraying, laser structuring processes are investigated with regard achievable interlaminar strength corresponding roughness parameters. The experiments carried out on EN AW-6082/polyamide 6 polymer-metal-hybrids, utilizing a...
High hardness and good wear resistance have been revealed for the high-entropy alloy (HEA) system AlCoCrFeNiTi, confirming potential surface protection applications. Detailed studies to investigate microstructure phase formation carried out using different production routes. Powder metallurgical technologies allow much higher flexibility in customisation of materials compared casting processes. Particularly, spark plasma sintering (SPS) enables fast processing feedstock, suppression grain...
Al2O3, Cr2O3, and TiO2 are most commonly used oxide materials for thermal spray coating solutions. Each shows unique properties comprising behavior in the process, hardness, corrosion, wear resistance. In order to exploit different advantages, binary compositions often used, while ternary not studied yet. Atmospheric plasma spraying (APS) of Al2O3-Cr2O3-TiO2 system was using blends plain powders with ratios identical parameters. Coatings from oxides were comparison. For these powder blends,...