bluuebunny/crossref_metadata_2025 huggingface dataset:
Inflasi dan Pengangguran Dalam Ekonomi Islam
Authors: Rasyid Andi Syahrul Ramadhan
Published: May 2022

Inflasi merupakan keadaan dimana terjadi kenaaikan harga barang secara terus menerus yang dapat menyebabkan menurunnya daya beli masyarakat karena secara riil tingkat pendapatannya juga menurun. Ada macam-macam inflasi tergantung pada faktor pencetus terjadinya inflasi. Dilihat dari besarnya laju inflasi dapat dibagi menjadi beberapa macam1, yaitu: Inflasi merayap (creeping inflation), inflasi menengah (moderate inflation), Galloping inflation, dan Hyperinflasi.
A single nucleotide variant on chromosome 16 residing within CDH11 distinguishes patients with luminal A breast cancer.
Authors: Mamoor Shahan
Published: May 2022

Molecular subtypes including the most common subtype luminal A drive patient outcomes in human breast cancer but the biological basis for this is not completely understood. We mined published microarray data (5, 6) to discover in an unbiased fashion the most distinguishing genetic and transcriptional features of tumors of each breast cancer molecular subtype. We identified a single nucleotide polymorphism, rs35197, residing within CDH11, as among the most significant genetic differences in the tumors of patients with luminal A breast cancer. In a separate cohort of patients with luminal A subtype breast cancer, we observed transcriptome-wide differential expression of a CDH11 transcript. Analysis of patient survival data revealed that CDH11 primary tumor expression was correlated with overall survival in human breast cancer. Sequence variation in the CDH11 gene may be important in understanding differences in genetic background that favor development of luminal A subtype human breast cancer.
Screening of Maize Genotypes against Maize Leaf Aphid [Rhopalosiphum maidis (Fitch)] under Field Condition at Chitwan, Nepal
Authors: Neupane Saraswati , Subedi Subash , Neupane Prazwal , Shrestha Ramesh Kumar
Published: May 2022

Thirty maize genotypes including five hybrids, eight quality protein (QPM) and seventeen full season open pollinated (OP) were screened for their resistance against maize leaf aphid (Rhopalosiphum maidis Fitch) at the research field of National Maize Research Program, Rampur, Chitwan, Nepal during the year 2019 and 2020. The design of the experiment was randomized incomplete block with three replications. The plot size was 2 rows of 5 m long with the spacing of 60 cm × 25 cm. The recommended dose of fertilizer for full season OP and QPM were 120:60:40 and for hybrid maize 180:60:40 N: P2O5:K2O kg/ha with farmyard manure 10 t/ha and seed rate was 20 kg/ha. Data on aphid incidence, severity, yield and yield components were recorded. Maize hybrids RML-95/RML-96 (18%) and Rampur Hybrid-10 (22%), two quality protein maize (QPM) S00TLYQ-AB (22%) and S99TLYQ-A (23%) and two full season OP genotypes TLBRS07F16 (24%) and ZM 627 (26%) were less susceptible to aphid infestation and resulted in higher grain yield. The findings could aid in the selection of maize genotypes for the development of aphid resistant and high-yielding maize varieties.
Reproductive and Productive Performance of Crossbred and Terai Cattle in Bardiya District of Nepal
Authors: Gautam Gokarna , Khadka Ujjwal
Published: May 2022

To compare the reproductive and productive performance of exotic crossbreds and indigenous Terai cattle under farmers' management condition, a household survey was carried out in 218 households of Bardiya, Nepal. Total of 262 cows [Jersey cross (n=107), Holstein cross (n=24) and indigenous Terai cattle (n=131)] were considered to determine the production and reproduction parameters.  The age at first calving in months was the lowest in Jersey crossbred (27.8±1.8) followed by Holstein cross (29.5±4.0) and Terai cattle (45.7±3) (P<0.05). However, the number of services per conception, calving to conception interval (in months) and inter-calving interval (in months) were shorter in Terai cattle (1.3±0.7, 3.4±1.4 and 12.6±1.9) compared to Jersey cross (1.7±1.3, 4.4±2.2 and 13.5±3.1) and Holstein cross (1.8±0.9, 5.7±2.8 and 14.9±4.7), respectively (P<0.05). Total 6.5% of cattle had a history of reproductive problems; Incidence of repeat breeding tended (P<0.1)) to be higher in Jersey cross (8.4%) and Holstein cross (8.3%) than in Terai cattle (3.0%). Daily peak milk yield (L/day) was significantly lower in Terai cattle (1.7±1.1) than Jersey cross (13.5±3.1) and Holstein cross (14.9±4.7). The lactation length (months) was significantly shorter in Terai cattle than exotic crossbreds. Consequently, the length of dry period (in months) was significantly longer in Terai cattle (5.2±2.1) than in Jersey cross (2.5±0.9) and Holstein cross (2.2±0.7). The reproductive performance parameters in exotic crossbred cows under the farmers' management condition were satisfactory; however, their  productivity was low. Thus, the good reproductive traits and variations in productivity of Terai cattle can be utilized in cross breeding programs.
Multi-Environment Screening of Nepalese Finger Millet Landraces against Blast Disease [Pyricularia grisea (Cooke) Sacc.)]
Authors: Ghimire Krishna Hari , Manandhar Hira Kaji , Pandey Madhav Prasad , Joshi Bal Krishna , Ghimire Surya Kanta , Karkee Ajaya , Gurung Suk Bahadur , Ghimire Netra Hari , Gauchan Devendra
Published: May 2022

Three hundred finger millet genotypes (295 landraces from 54 districts and five released varieties) were evaluated for leaf, finger, and neck blast resistance under natural epiphytotic conditions across three hill locations in Nepal, namely Kabre, Dolakha (1740m); Vijaynagar, Jumla (2350 m); and Khumaltar, Lalitpur (1360 m) during the summer seasons of 2017 and 2018. The highest incidence of leaf, neck, and finger blast was observed at Lalitpur, followed by Dolakha and Jumla, whereas the overall disease incidence was higher in 2018 compared to 2017. Combined analysis over environments revealed non-significant differences among accessions for leaf blast, but the difference was highly significant for neck and finger blast. Correlation analysis suggested that there was a strong positive correlation between neck blast and finger blast (r = 0.71), leaf blast (seedling stage) and neck blast (r = 0.68), and leaf blast (seedling stage) and finger blast (r = 0.58) diseases. Among 300 accessions, 95 had lower scores for finger blast, 30 for neck blast, and 74 for leaf blast than the score of Kabre Kodo-2, the latest released variety in Nepal. Genotypes NGRC04798, NGRC03478, NGRC05765, NGRC03539, NGRC06484, NGRC01458, NGRC01495 and NGRC01597 were found the resistant genotypes for finger blast (2.1-2.3) and neck blast (1.5-2.3) based on pooled mean scores. This study shows the variable reactions of finger millet genotypes against blast disease in various environments and reports the promising landraces having field resistance to leaf, finger, and neck blast, which ultimately serve as important donors for blast resistance in finger millet breeding.
Development of the Thermal Spray (TS) Industry Into Year 2000 From a Spray Shop Point of View
Authors: Wasserman Chr.
Published: May 2022

Thermal spray coatings play an important role in the field of surface protection. Threats and opportunities in the thermal spray industry include TS process developments, impact of health and safety, standardization, pre/post treatments, non destructive evaluation of coating characteristics and environment. In this paper, the European thermal spray industry size is estimated. Examples of customer requirements from typical Original Equipment Manufacturers to industry end users are also discussed. The paper provides some views on the ability of a particular spray shop to compete and grow given the market conditions. In addition, it discusses internal benchmarks used by Terolab Services. Paper includes a German-language abstract.
Potentiodynamic Corrosion Testing of HVOF Sprayed Stainless Steel Alloy
Authors: Eminoglu C. M. , Knight R. , DeFalco J. , Dorfman M.
Published: May 2022

HVOF-sprayed stainless steel coatings are potential candidates for protection against water corrosion. However, the process parameter "window" leading to acceptable corrosion behavior has yet to be determined. With potentiodynamic tests, this paper examines the corrosion behavior of metallic, thermally sprayed coatings under carefully controlled conditions in order to gain an insight into their performance "in service". The influence of the variations in the fuel:oxygen ratio, in the total gas volume and in the spraying distance, on the corrosion process of HVOF-sprayed stainless steel coatings on steel substrates with a low carbon content is determined by means of potentiodynamic measurements. The results are correlated with a characterization of the microstructure to understand the influence and role of oxide content, porosity, and coating morphology. Some comparisons with VPS coatings are also made. Paper includes a German-language abstract.
Mechanisms of Oxidation of Thermally Sprayed Coatings
Authors: Sobolev V. V. , Guilemany J. M.
Published: May 2022

This paper investigates the oxidation that occurs during the flight movement of a powder particle and during the spatter solidification in the thermal spray process. The effects of oxidation on droplet flattening, on the mechanical and thermal interactions between spatter and substrate, on spatter morphology, on porosity, and on adhesion are studied. The influence of wetting and oxygen dissolution is analyzed. The experimental results show that during High Velocity Oxy-Fuel spraying of the chromium carbide-nickel-chromium powder, the relative mass of chromium oxide in the coating is about 4.95%. The theoretical results agree well with the experimental observations. Paper includes a German-language abstract.
Metallische Beschichtungen zum Schutz gegen schweren Verschleiß (Metallic Coatings for Heavy-Wear-Protection)
Authors: Reimann H.
Published: May 2022

Metallic coatings as protection against extraordinary attack of mechanical wear mechanisms such as welded layers or sintered coatings are wordwide standardized. There exists a lot of empirical knowledge, but no exact method is known to foresee the grade of wear in dependance of all important influences in tribological systems. Paper text in German.
Investigation of Thermal Spray Coatings for Applications with Abrasion, Erosion, Corrosion and Cavitation Wear
Authors: Berreth K. , Buchmann M. , Gadow R.
Published: May 2022

Turbine blades in hydropower plants have to withstand the most severe seasonal loading conditions when the river water is heavily loaded with sediments. Welded blade surfaces are considered state of the art, but they cannot withstand the aggressive, eroding and abrasive loading conditions in the major rivers in China. Once a year there is flooding with a maximum amount of sediment in the river water. This is why coating systems with maximum wear resistance must be developed, examined, produced and tested over a maximum period of time. In this article, the wear results of various coating systems examined in a special test facility are described in order to obtain comparable results from several proposed coating systems together with material classification tests. Paper includes a German-language abstract.
The Deposition Efficiency of Thermally Sprayed Nanopowders
Authors: Jaffe S.M. , Lavernia E.J.
Published: May 2022

Thermal sprayed nanoscale materials produce coatings with enhanced properties. Thermally spraying nanopowders, in non-agglomerated form, include several potential advantages. These advantages can not be tested because nanoparticles do not have the inertia required to cross streamlines in typical plasma spray flows. Hence, they are swept away without depositing on the substrate. Analysis of inertial deposition reveals that the non-dimensional Stokes number largely characterizes deposition efficiency. Under low pressure plasma spray conditions, with reduced stand-off distance, the Stokes number of nanopowders can be made to approach the Stokes numbers of typical thermal spray powders. This paper explores the conditions that make the inertial deposition efficiency of nanoparticles quantitatively similar to the typical inertial deposition efficiency of microparticles. Paper includes a German-language abstract.
Spraying Characteristics of Nanostructured Zirconia Particles
Authors: Lima R.S. , Senturk U. , Berndt C.C. , Lima C.R.C.
Published: May 2022

In this paper, the processes as well as the first results regarding the economic efficiency and plasma fuel properties of nanostructured zirconium oxide powder particles are explained. The paper evaluates values for porosity, hardness, roughness, and crystallite size. In addition, both the morphology of the powder particles and the spatter are analyzed by SEM, and cross sections of the coatings are observed using optical microscopy. These results are compared to coatings made from a commercially available yttria stabilized zirconia powder. Paper includes a German-language abstract.
Investigation of Transferred-Arc Cleaning for Thin Film Removal
Authors: Hollis K. , Castro R. , Bartram B.
Published: May 2022

Transferred-arc cleaning and roughening as discussed in the patent by Muhlberger is often used as a surface preparation method prior to low pressure plasma spray (LPPS) deposition of coatings. In this article, electrically transmitted arc cleaning is investigated as a precision cleaning method for thin films lubricating substrates as well as traditional cleaning and roughening for LPPS. A Box-Behnken reaction surface construction test is carried out with variation of the chamber pressure, the substrate distance and the torch current taking into account the transferred arc voltage, the voltage fluctuation, the current, the emitted light, and the surface cleanliness. The results of the analysis show the effect of the various independent quantities on the measured responses. Different stages in the cleaning process are determined by their sample cleanliness, their voltage level, their voltage fluctuation, their emitted light and their rate of erosion. Paper includes a German-language abstract.
Hochgeschwindigkeitslichtbogenspritzen (High Velocity Arc Spraying)
Authors: Bach Fr.-W. , Babiak Z. , Duda T. , Tegeder G.
Published: May 2022

For obtaining higher particle velocities and consequently dense coatings, a closed nozzle system for atmospheric arc spraying was developed. The proposed system is characterized by a nozzle geometry which allows an expansion of the atomizing gas only in downstream direction. First coatings, obtained with this system exhibited promising results due to dense structure and high adhesion. Paper text in German.
A Study and Comparison of Spray Stream Formation Using Two Wire Arc 90-Degree, and 0-Degree Spray Processes
Authors: Benary R. , Margolies J. , Gutleber J.
Published: May 2022

Inside diameter (ID) spraying with a two-wire gun for thermal spraying has become an established practice. While the simplicity of the two-wire arc process is tempting, there is a marked difference between the coating microstructures obtained with standard two-wire arc and two-wire arc ID systems. In conventional two-wire arc spraying, the arc is partially surrounded by the nozzle, which leads to the fused tips being enveloped by the atomizing gas flow. In comparison, the right-angled arc is unprotected if the airflow hits the arc at 90 degree. In this paper, the particle formation process is investigated using diagnostic tools such as Laser Strobe Vision (Control Vision) and DPV2000. Although the data collected may not fully encompass the breadth of the phenomena associated with two-wire arc spraying, a comparison was made between the 0 degree and 90 degree spray processes. Paper includes a German-language abstract.
Effects of Nozzle Fluid Dynamics on the Dynamic Characteristics of a Plasma Spray Torch
Authors: Duan Z. , Heberlein J. , Janisson S. , Wittmann K. , Coudert J.F. , Fauchais P.
Published: May 2022

This paper is devoted to the investigation of the dynamics of the plasma jet, which is produced by a subsonic DC spray torch operated with an argon-helium mixture as the plasma gas. It focuses on studying the effect of some parameters which influence the arc attachment inside the anode nozzle. For this purpose, the paper uses different means of gas injection, that is straight flow injection and vortex flow injection, and anodes which have experienced different degree of wear. A heavily eroded anode is characterized by large voltage fluctuations at relatively low frequencies, while straight gas injection at high current levels led to a low average voltage with small fluctuations and to low burner performance. The results are interpreted by assuming changes in the thickness of the cold interface between the arc and the anode, and conclusions are drawn as to the voltage characteristics indicative of good torch operation. Paper includes a German-language abstract.
PTA Reclamation of Cast Iron and Nickel-Base Alloy Substrates with Films Deposited by Tape Casting
Authors: Leylavergne M. , Chartier T. , Grimaud A. , Fauchais P.
Published: May 2022

Plasma transferred arc (PTA) allows to weld a metallic coating to a metal substrate in order to improve their wear and corrosion resistance. This process is mainly used for steel reclamation and the principal applications are coatings of valves, valve seats in automotive industry and extruder screws for plastic industry. This paper describes the tape casting of NiCu and NiCoCrAlTaY particles on Ni-based alloys and the various organic additives used in addition to a homogeneous metallic film. The initial results of treating these films with PTA regeneration are described. Paper includes a German-language abstract.
Möglichkeiten des reaktiven thermischen Spritzens von neuen Eisenbasislegierungen (Possibilities of Reactive Thermal Spraying of New Ferrous Alloys)
Authors: Brandt O.C. , Siegmann S.
Published: May 2022

Three iron-base alloys with different chemical compositions were developed and sprayed in these investigations. The effect of different process parameters (primarily a reactive APS and VPS process) on the attainable nitrogen concentrations and on the resulting coating structure is demonstrated. Furthermore, the metallurgical interaction between the selected alloys as a result of the spraying process is described and the properties (such as hardness, porosity and bond strength) are discussed. The objective of this development is to form nanostructured deposits of the vanadium-nitride type with a crystal structure similar to that of the austenitic lattice. The formation, appearance and type of deposits are described as functions of the process parameters. Paper text in German.
Triplex - A High Performance Plasma Torch
Authors: Barbezat G. , Zierhut J. , Landes K.D.
Published: May 2022

Plasma spraying is a well established process for producing ceramic and metallic coatings for many technical applications. The quality of the coatings and the efficiency of the process depend on the powder and on the operating parameters as well as on the plasma torch properties. Whereas many efforts have been made on creating novel powders and on optimizing the operational parameters, the principle, however, of DC plasma torches has remained unchanged for many years. This was the reason for developing a novel DC plasma torch system. This paper presents the construction and operating principle of this innovative torch system. Its high performance is demonstrated in selected ceramic coatings. Paper includes a German-language abstract.
The Development of a Low to Medium Power Atmospheric Mobile Plasma System
Authors: Zwetsloot M. , Mor P. , Prince R.
Published: May 2022

In order to coat hard-to-reach coating areas or parts with a complex geometry, it is often necessary to reduce the power of the "plasma flame." Conventional plasma systems are not designed for operation at lower power levels. Plasma arc stability as well as coating quality and performance are significantly reduced below a threshold current level. Conventional plasma systems are therefore unsuitable for this type of application. A novel inverter-based plasma system has been developed to overcome this problem. This paper provides information about this plasma system with technical properties and some application examples. The goal is to develop a plasma system designed to operate at lower power levels and at the same time be used for general "every day application". Paper includes a German-language abstract.
Thermal Sprayed Thin Coatings Produced by LPPS (Low Pressure Plasma Spraying)
Authors: Loch M. , Barbezat G.
Published: May 2022

The production of functional coatings using Low Pressure Plasma Spraying (LPPS) has been successfully introduced into industrial application. Especially in the area of gas turbine coatings for resistance to hot gas corrosion, the efficiency and reliability of the LPPS process for consistent high quality coatings has provided it's leading position within the aircraft and energy market. Functional coatings with a specific thin coating thickness are interesting for many applications. In addition to the benefit of saving material, which is not required for the coating function itself, and the subsequent cost savings within the coating process, further advantages such as greater flexibility in the construction of the end product will be possible. This paper discusses the potential of LPPS technology in the area of thin coatings. Paper includes a German-language abstract.
The High Frequency Pulse Detonation (HFPD) Spray Process
Authors: Fagoaga I. , Barykin G. , de Juan J. , Soroa T. , Vaquero C.
Published: May 2022

A combination of pulsed combustion and advanced thermal spray technology has led to the development of the novel High Frequency Pulse Detonation (HFPD) spray technology by Aerostar Coatings. In the HFPD process, the flow of gaseous products from cycled explosions in the spray gun, is used to accelerate and heat the spray particles. This paper provides a fundamental description of this cyclical process, with the main differences to spray processes with stationary flow and also to traditional detonation spraying techniques in the center. Paper includes a German-language abstract.
Plasma Coating from the Synthesized Composite Powders
Authors: Vityaz P. , Belyaev A. , Talako T. , Koval V.
Published: May 2022

Due to their attractive combination of properties (high resistance to oxidation and wear, high melting point, and lower density) iron and nickel aluminides show promise for the development of advanced materials and coatings However, poor room temperature ductility and susceptibility to intergranular cracking restrict their commercial application. To provide the structure required composite materials produced by the self-propagating high-temperature synthesis (SHS) are promising. In this paper, the potential of thermally sprayed NiAl/aluminum oxide and FeAl/aluminum oxide composite powders produced using the SHS method is evaluated. The results of the structure and property investigations for the synthesized powders as well as for the resulting plasma coatings are presented. Paper includes a German-language abstract.
On-Line Process Monitoring During Spraying of TTBCs by Acoustic Emission Analyses
Authors: Lugscheider E. , Ladru F. , Crostack H.-A. , Reuss G. , Haubold T.
Published: May 2022

This paper describes the development of an online process control system for spraying thick thermal barrier coatings as part of a Brite Euram research project. In addition to the evaluation of the substrate temperature, a system for acoustic emission analysis for particle impact and for controlling crack propagation is developed. The procedure, the problems overcome, and the results obtained are described. Paper includes a German-language abstract.
Characterization of Plasma Spray Processes by Monitoring the State of the Sprayed Particles
Authors: Leblanc L. , Moreau C. , Legoux J.-G. , Arsenault B.
Published: May 2022

Novel thermal spray technologies must be thoroughly tested before they can replace the existing processes. In order to reproduce the properties of the accepted coatings, numerous test pieces must be sprayed and characterized by many different combinations of the available spray parameters. The method is time-consuming and often not very efficient. In this paper, a different approach is considered, whereby the state of the sprayed particles is characterized during the flight. The main objective is to examine the possibility to spray particles with similar in-flight characteristics with two different plasma guns in order to spray similar coatings with both guns. It is observed that the SM-F100 plasma gun can produce similar yttria stabilized zirconia particle jets as those sprayed with the F4-MB gun with 50% less electric power. Paper includes a German-language abstract.
Vergleichende Untersuchungen zur Partikelgrößenanalyse von Spritzpulvern (Comparative Surveys for Analysing Particle Sizes)
Authors: Suk H.-G. , Lugscheider E. , Killing R. , Lee H.-K.
Published: May 2022

Grain size, grain distibution, morphology and microstructure are essential properties of powders for thermal spaying. The present article concerns with the comparison of different methods of particel size measurement. The results indicate, that the grain distribution differs from method to method and there is no correlation factor existing to convert the results of different test methods. So, for exact stipulation of powder grain sizes the method for determination has to be declared. Paper text in German.
Influence of HVOF Process Parameters on Particle Parameters During Spraying of Metal Alloys
Authors: Lugscheider E. , Herbst Chr. , Fischer A. , Zhao L.
Published: May 2022

The processing of metallic alloys with the atmospheric HVOF process requires a uniform setting of the particle parameters, particle temperature and velocity, as these determine the tendency towards oxidation and the flattening behavior of the particles. Using the example of a NiCr alloy, this paper examines the effects of different particle diameters of a typical HVOF grain fraction on the achievable uniformity of processing. In addition, particle parameters are correlated with the process variables fuel gas composition and spray distance as well as the resulting application efficiency in order to determine whether they can be influenced. The particle properties of surface temperature and speed are characterized with the aid of a high-speed particle pyrometer. It is shown how, with the help of this particle diagnosis, an on-line process control can be used as proof of quality assurance. Paper includes a German-language abstract.
Cyclic Deformation and Fatigue Damage of Aluminum Alloy and Steel HVOF Sprayed With WC-Co Coatings
Authors: Ibrahim A. , Berndt C.C. , Senturk U.
Published: May 2022

This paper investigates the effect of HVOF thermally sprayed WC-Co coatings on the cyclic deformation of the aluminum alloy 2024-T4 and the steel SAE 12L14. Strain gages are glued on the specimen surface to measure the strain response after certain intervals of fatigue cycles. The strain is also measured during the fatigue test. A calibrated beam is used to apply the bending moment and the stress calculated using the flexural formula. The stress-strain curves for uncycled and cycled specimens are determined. The dynamic strains for the coated and uncoated specimens are also monitored during the fatigue test. Paper includes a German-language abstract.
Praktische Erfahrungen mit dem Hochgeschwindigkeits-Flammspritzsystem Diamond Jet Hybrid in der Papierindustrie (Practical Experiences with the HVOF Diamond Jet Hybrid System In Paper Industry Applications)
Authors: Höhle H.-M. , Zimmermann S. , Gwosdz-Kaupmann M.
Published: May 2022

The demand for better paper qualities and for higher speed of the paper web requires a constant technological development of the existing calendering process. An important factor in modern calendering is the heated metal roll. Its surface has an important influence on the gloss and the smoothness of the paper. During operation these rolls are heated to temperatures of up to 200°C. Additionally, the rolls are exposed to severe abrasive wear by fine hard filler materials and to corrosion by the moisture of the paper. The SUMECAL coating systems - especially developed for calender rolls - surpass the hard chromium platings by far regarding the scratch and wear resistance and demonstrate better calendering properties. Paper text in German.
HVOF-Sprayed Functionally Gradient Coating
Authors: Jokinen P.
Published: May 2022

Thermally sprayed alumina coatings are widely used to improve wear resistance and heat insulation of steel and other metals. Usually these coatings have been made by plasma or flame spraying. HVOF-sprayed alumina coatings are more wear resistant and better bonded to the base material than with plasma and flame spraying. This paper presents a functionally gradient coating (FGC) of alumina and NiAl made with HVOF. It examines the microstructure, composition, hardness, adhesion, and resistance against thermal cycling of HVOF-sprayed FGC. The performance of FG-coating was proven with reference coatings made by plasma and flame spraying. Paper includes a German-language abstract.
Anisotropic Behaviour of the Structure-Properties Relationship in HVOF Self-Standing Forms
Authors: Guilemany J.M. , Franch R. , Lorenzana C. , Llibre J.
Published: May 2022

The HVOF forming is a process that permits to obtain wear resistant self-standing forms. The self-supporting forms that are obtained through the reshaping process by means of thermal spraying have two free surfaces that do not necessarily have the same structure or the same properties. This paper investigates the mechanical properties of the obtained in relation to the structure. It compares the structure-property relationship of the internal and external surfaces. The results show the anisotropic behavior of the internal and external free surfaces and their difference to the cross section. The structure of the system is characterized in terms of its nature, phase distribution, composition, and porosity. For the mechanical properties, the paper examines the microhardness and the modulus of elasticity of the material. Paper includes a German-language abstract.
Entwicklung und Reproduzierbarkeit von plasmagespritzten TBCs (Spraying and Improving Reproducible Plasma Sprayed Thermal Barrier Coatings)
Authors: Malléner W. , Vaßen R. , Rauwald K.-H. , Siebert B. , Stöver D.
Published: May 2022

The new Triplex-burner was used to develop 7 wt% Y2O3 stabilised ZrO2 thermal barrier coatings and to optimise the process parameters with respect to reproducibility. The investigations were focused on spray efficiency and coating porosity. Porosity levels and porosity distribution were measured with mercury intrusion, which turned out to be a very reliable characterisation technique. High reproducibility could be achieved in particular for low argon fluxes: the deviation of the porosity levels was below about 4%. Paper text in German.
Comparison of Vacuum and Atmospheric Plasma Sprayed ZrO27Y2O3 Thermal Barrier Coatings
Authors: Bach Fr.-W. , Babiak Z. , Unterberg W. , Duda T.
Published: May 2022

This paper examines thermal insulation layer systems with regard to their thermal shock resistance, internal stresses, adhesive tensile strength and layer morphology. The research was conducted on a duplex coatings system consisting of zirconium dioxide/yttrium oxide ceramic coatings and CoNiCrAlY oxidizing and corrosion resisting coating. In all thermal insulation layer systems, the bonding layers were produced by vacuum plasma spraying. The thermal insulation layers were produced on the one hand by atmospheric plasma spraying and on the other hand by vacuum plasma spraying, and their properties were compared with one another. Paper includes a German-language abstract.
Flame Spraying of PEEK and PPS Polymers for Engineering Applications
Authors: Lugscheider E. , Fischer A. , Herbst Chr.
Published: May 2022

Thermally sprayed coatings made of polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) are becoming increasingly interesting, especially for corrosion protection applications at elevated temperatures in the chemical industry. In contrast to conventional polymers these materials melt at much higher temperatures. Furthermore, PPS and PEEK show enhanced mechanical and chemical stability. Instead of HVOF and plasma spraying, in this paper much simpler and low-cost flame spraying is used because of these advantages. The polymers are investigated along the entire deposition process in order to exclude possible decomposition. Attempts are made with various adhesive layers to reduce the unacceptably high preheat temperatures. The corrosion protection features are examined by means of corrosion tests with various media. The results of the experiments presented in this paper promise coatings of high performance thermoplasts a great future as anticorrosive coatings. Paper includes a German-language abstract.
Diagnostics on a Thermal RF Plasma Process used for the Evaporation of Zirconia Powders
Authors: Buchner P. , Schubert H. , Weiß M. , Willée K. , Uhlenbusch J.
Published: May 2022

This paper investigates the problem of complete evaporation of zirconium oxide powders that are injected into a thermal RF plasma. Particle trajectories and evaporation are studied using optical emission spectroscopy and laser Doppler anemometry. Model calculations are compared with the results of process diagnostics. It is observed that axial emission profiles confirm the influence of the particle size on the evaporation behavior. Paper includes a German-language abstract.
New Applications and New Product Qualities by RF Plasma Spraying
Authors: Henne R. , Borck V. , Müller M. , Ruckdäschel R. , Schiller G.
Published: May 2022

DC plasma spraying with its products has gained a high technical importance. With the availability of technically reliable high-frequency plasma torches whose basic development can be traced back to about 40 years ago, some of the disadvantages of the DC spray method are no longer existing or can be avoided to a great extent. This paper describes the principle, construction, and function of high-frequency plasma torches in which the plasma is generated by induction and metallic electrodes are not required (as is the case with conventional DC plasma torches). Typical examples of HF plasma spray application are discussed. Paper includes a German-language abstract.
Comparison of DC and RF Plasma Sprayed Carbon Short Fibre Reinforced Aluminum Coatings
Authors: Fleischer K. , Wielage B. , Müller M. , Henne R. , Borck V.
Published: May 2022

This paper compares the features of direct current and radio frequency (RF) plasma spraying, but also the properties of aluminum coatings that are reinforced with short carbon fibers and manufactured using these two methods. It shows that the embedding of the fibres during the RF plasma spray process is very poor due to the low velocity of the plasma jet. Paper includes a German-language abstract.
Plasma Sprayed Ceramic Coatings for Ultrasonic Wave Guidance in Severe Environments
Authors: Voyer J. , Marple B.R. , Jen C.-K.
Published: May 2022

This paper aims to analyze the effect of the nature of the core material, the geometry of the buffer rods, as well as the nature and thickness of the cladding material on the ultrasonic propagation properties of these guidance components. The development of ultrasonic waveguides was studied in order to address the need for operation under strict conditions. The effects of the composition and thickness of the cladding as well as the type and geometry of the core were investigated with straight and tapered aluminum oxide and 1018 steel rods for the core and with plasma-sprayed aluminum oxide or aluminum oxide-chromium oxide for the coating. The results show that tapered plated buffer rods perform better than their unclad straight counterparts. They also indicate that the addition of chromium oxide to aluminum oxide is promising in a broader temperature range in which these conductors can be used. Paper includes a German-language abstract.
Plasma Sprayed Coating – Substrate Interface Study
Authors: Písacka J. , Laub D. , Buffat F.
Published: May 2022

This paper examines an aluminum oxide coating plasma-sprayed onto a substrate made of high-quality stainless steel by means of light microscopy, X-ray diffractometry, and scanning and transmission electron microscopy (TEM). The aim is to determine the phases that form preferentially at the transition. It is observed that high amount of corundum phase was found in a plasma sprayed white alumina coating. XRD phase analysis of the coating indicated that all three major alumina phases were present: alpha-, gamma-, and delta-aluminum oxide. Further development in the field of TEM sample preparation is required in order to obtain larger electron-permeable surfaces, since it is not clear whether the alpha-aluminum oxide found at the transition is in the form of a spatter or a grain introduced by sandblasting. Paper includes a German-language abstract.
Influence of Substrate Deformation on Formation of Splats During Thermal Spraying
Authors: Sobolev V.V. , Guilemany J.M.
Published: May 2022

Due to high kinetic energy of an impinging droplet a strong elastic deformation of the substrate and the formation of its curvature occur which influence the dynamics of the droplet flattening (particularly the thickness and the diameter of a splat) and a pressure formed upon the droplet impact. This paper involves investigation of these phenomena and the development of the simple analytical formulae needed by the engineering practice which enables to estimate the influence of the substrate deformation on the droplet flattening and the high pressure generation. The analytical results are obtained with regard to the variation of the splash properties and the pressure that arises when the droplet is flattened during thermal spraying. The splash curvature caused by the drop impact is taken into account. The paper also analyzes the role of surface effects. The results obtained show good agreement with the experimental observations. Paper includes a German-language abstract.
Manufacturing and Experimental Evaluation of Combined Ceramic Polymer Coating Systems for Tribological Application
Authors: Scherer D. , Gadow R. , Killinger A.
Published: May 2022

This paper aims to fabricate wear resistant composite coatings on light metal substrates which also exhibit low friction coefficients. It demonstrates that combined ceramic polymer coating systems are a powerful concept for industrial applications where high wear resistance, creep resistance and compressive strength as well as low friction coefficients are required. The results show that, under the specific experimental conditions used, the titanium dioxide layer in connection with the applied lubricant lacquer showed better performance than the mixed aluminum oxide/titanium dioxide layers. Paper includes a German-language abstract.
The Optimization of Plasma Sprayed Ni-50%Cr Coatings by Orthogonal Experimental Design
Authors: Li C.-J. , Li F.-H. , Sonoya K.
Published: May 2022

In this paper, the influence of the plasma spray parameters on the mechanical properties of Ni-50% Cr coatings is systematically studied using the method of orthogonal regression test planning. The target properties include adhesive strength, micro-hardness, grinding wear, and erosion wear. The three spray parameters used as variables are plasma arc current, Ar flow rate, and spray distance. From the regression formulas, it is concluded that the effects of the spray parameters on the properties largely depend on the individual properties. Paper includes a German-language abstract.
Laser Shock Processing of Al-SiC Composite Coatings
Authors: Schnick T. , Hofmann U. , Steinhäuser S. , Wielage B. , Tondu S. , Peyre P. , Bartnicki E. , Pawlowski L.
Published: May 2022

Laser shock processing (LSP) is a surface treatment similar to shot peening, in which the compressive stresses in the material are created by laser-induced mechanical impacts. The tensions are of sufficient intensity to modify the microstructure and properties. In this paper, the laser pulses are generated with a power density of 5 to 8 GW/centimetres square with a neodymium laser. The glass laser is used to treat Al+SiC composite coatings, which were initially applied using the high-speed oxygen fuel spray technique. The laser-processed samples are prepared metallographically and examined for their microstructure with a scanning electron microscope. The latter is also used to investigate the surface morphology of laser-treated samples. Finally, the microhardness and the vibration wear resistance of the coatings are tested and compared with the data obtained for the samples in the sprayed state. Paper includes a German-language abstract.
Changes in Properties of Detonation Sprayed Coatings as a Function of Temperature
Authors: Babul T.
Published: May 2022

This article presents one of the most advanced technologies for the application of powder coatings, the detonation spray method. The devices for measuring the temperature and the velocities of the powder particles are presented and the results obtained are shown. The article deals with results from wear tests as well as from fatigue strength tests. The tests are carried out on the coatings of the Ni-Cr-B-Si type applied to C45 steel. In addition, X-ray examinations, linear distribution of the chemical elements, microhardness measurements and metallographic examinations are carried out. The coating properties of the detonation-sprayed layers are compared with the same coatings, which were applied by means of plasma or flame spraying. Paper includes a German-language abstract.
Numerical Results of Off-Angle Thermal Spray Particle Impact
Authors: Bussmann M. , Chandra S. , Mostaghimi J.
Published: May 2022

This paper presents results regarding the influence of the spray angle on the spray shape. Simulations of the liquid dynamics of the impact of Ni particles, which were the characteristic of both HVOF and DC plasma conditions, are carried out. The results show that the splashes stretch with decreasing spray angle and confirm previous experimental observations to the effect that the splash area varies little with the spray angle. In addition, the results indicate that more than 90% of the material is applied "behind" the point of impact, even at spray angle is equal to 45 degree. Paper includes a German-language abstract.
Investigations of Thermal Barrier Coatings with Loading and Unloading to Various Stress Levels
Authors: Lin C.K. , Senturk U. , Lima R. , Berndt C.C. , Shieh J.C. , Lee P.Y.
Published: May 2022

In this paper, plasma sprayed thermal barrier coatings (TBCs) with and without bond coat are stressed to various stress levels under four point bending with in situ acoustic emission (AE) to monitor any cracking activities. Micro- and macro-cracks occurring during the tests are investigated to better understand the failure mechanisms of TBCs. The results show that limited AE activities were detected in the first four stress-relief cycles, while plastic deformation and the greatest AE activity were observed when the applied load exceeded the yield point. In addition, they show that a TBC system that contained an adhesive layer had less AE activity (cracking events) than the TBC without an adhesive layer. In addition, the samples tested at a main speed of 5 micrometer/s resulted in a higher AE activity than the samples tested at 10 micrometer/s. With increasing plastic deformation, macro cracks and surface cracks also occurred. Paper includes a German-language abstract.
Processing and Mechanical Properties of Plasma Sprayed Thermal Barrier Coatings
Authors: Senturk U. , Lima R.S. , Berndt C.C. , Lin C.K. , Lima C.R.C.
Published: May 2022

In this paper, the mechanical properties and cracking features of yttria stabilized zirconia with and without bond coat on steel substrates is investigated. Four point bending tests have been used to evaluate the mechanical properties, while acoustic emission (AE) has been used to in situ monitor the cracking behavior during the bend tests. In the sprayed state, the samples were characterized by four-point bending tests with local noise emission. In comparison with the substrate, the coated samples showed an increased flow pressure. It is also shown that the processing parameters, the cooling, and the adhesive layer have a significant influence on the flow pressure. It is proven that the cooling affects the behavior of the load-displacement curves. The AE analysis shows the different deformation behavior of the coating-substrate system for the different processing conditions. This is supported by the surface crack analysis. Paper includes a German-language abstract.
The Stiffness of Plasma Sprayed Zirconia Top Coats in TBCS
Authors: Thompson J.A. , Clyne T.W.
Published: May 2022

Thermal barrier coatings systems are composed of a zirconium dioxide-(6 to 8 wt.%) yttrium oxide ceramic top coat about 300-500 micrometer in thickness, deposited either by air plasma spraying or electron beam assisted physical vapour deposition, over an MCrAlY (M = Ni, Co or NiCo) bond coat, about 100 micrometer thick, deposited by vacuum plasma spraying. In this paper, the stiffness of as-sprayed zirconia is measured using three different techniques, namely cantilever beam bending, ultrasonic resonance and nanoindentation. The paper explores the effect of post-deposition heat treatment on the value obtained. The results show that the cantilever bend technique, employed with a high precision scanning laser method of displacement measurement, was found to be the most reliable procedure. Paper includes a German-language abstract.
Conversion of Silanes Into SiC by RF Plasma Technology
Authors: Bouyer E. , Müller M. , Schiller G. , Henne R.
Published: May 2022

This paper reports on the synthesis of SiC material through the decomposition of silanes in a thermal high frequency (HF) plasma. The process is based on thermal plasma technology for chemical deposition from the gas phase and on suspension plasma spray technology, in which a liquid or suspension is injected axially and atomized in the plasma flame. The liquid silane then decomposes, and forms SiC with some gaseous by-products such as HCl. Various plasma parameters were varied, for example the plasma power level, the plasma gas composition, the chamber pressure, and the silane composition. The paper also presents first investigations into the elementary and phase composition as well as the morphology of the powders and coatings. Paper includes a German-language abstract.
Komponenten- und Verfahrensentwicklung beim DLR für das DC- und das HF-Plasmaspritzen (Components and process development of DC- and RF-plasma spraying at the German aerospace center DLR)
Authors: Borck V. , Schneider G. , Henne R. , Schiller G. , Fischer M.
Published: May 2022

More than 20 years the Institute of Technical Thermodynamics of the German Aerospace Center (DLR) in Stuttgart has been active in the field of plasma spray technology with improvements of spray equipment and their application. At the beginning the DC vacuum plasma spray method was in the center of interest and knowledge gained from rocket technology helped to develop supersonic nozzles for the plasma spray torches producing plasma jets with increased velocity and improved laminarity in order to get denser coatings with higher quality. In the meantime also nozzles for subsonic conditions with controlled expansion of the plasma jet leading to considerably increased deposition efficiency were developed as compatible parts for already existing equipment and made available on the market. In the next step also the DC plasma torches themselves have been improved. Recently a modern equipment for RF plasma technology could be developed and installed, where some new ideas could be realised. Paper text in German.