bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Oxidation behavior of ODS iron aluminides
Authors: Pint B. A. , Tortorelli P. F. , Wright I. G. 
Published: May 2005

AbstractOxide‐dispersed Fe‐28at.% Al‐2%Cr alloys were produced by a powder metallurgy technique followed by hot extrusion. A variety of stable oxides were added to the base alloy to assess the effect of these dopants on the oxidation behavior at 1200°C in air and O2. An Al2O3 dispersion flattened the α‐Al2O3 scale, but produced none of the other reactive element effects and had an adverse influence on the long‐term oxidation behavior. A Y2O3 dispersion improved the alumina scale adhesion relative to a Zr alloy addition at 1200 and 1300°C. However, the Y2O3 dispersion was not as effective in improving scale adhesion in Fe3Al as it is in FeCrAl. This inferior performance is attributed to a larger amount of interfacial void formation on ODS Fe3Al.
Oxidation‐Sulphidation of iron aluminides at high temperature
Authors: Stott F. H. , Chuah K. T. , Bradley L. B. 
Published: May 2005

AbstractAn investigation has been carried out into the oxidation‐sulphidation resistance of a series of novel iron aluminides, containing 5 wt% Cr, 0.2 wt% Zr, from 0 to 0.3 wt% Y and from 8 to 16 wt% Al, at 500°C to 700°C. The test environments were H2/H2O/H2S gas mixtures, giving oxygen and sulphur partial pressures in the ranges of 10−24 to 10−31 atm and 10−9 to 10−11 atm respectively. The effects of preoxidation on the degradation resistance have also been studied. For comparison, several standard Cr2O3‐forming and Al2O3‐forming alloys were included in the programme.In general, the Al2O3‐forming intermetallics and alloys were much more resistant to degradation than the Cr2O3‐forming alloys while, in all cases, preoxidation increased the time to the onset of breakaway‐type corrosion resulting from the initiation and growth of sulphides. In environments in which the Cr2O3‐forming alloys developed thick sulphide scales, it was found that the iron aluminides developed and retained protective Al2O3‐rich scales more effectively than the conventional Al2O3‐forming alloys. At the relatively low temperatures of these tests, it was more difficult to establish the protective scale than at high temperatures, particularly on the alloys of relatively low aluminium concentration. Thus, an iron aluminide containing 16 wt% Al showed good degradation resistance under all conditions while an aluminide containing 8 wt% Al developed more extensive sulphides at 500°C that at 700°C. Overall, the resistance of the intermetallics to degradation increased with increasing aluminium concentration, although none of them showed excessive sulphidation in the 50 h test programmes.
Metal dusting of Fe3Al and (Fe,Ni)3Al
Authors: Strauß S. , Krajak R. , Palm M. , Grabke H. J. 
Published: May 2005

AbstractMetal dusting is a deterioration of metallic materials in strongly carburizing atmospheres under disintegration into a dust of carbon and fine metal particles (coke). The intermetallic compound Fe3Al is also very susceptible to metal dusting and disintegrates under formation of vast amounts of coke. The mechanism corresponds to the metal dusting of iron and steels, Fe3C is formed as an intermediate and the Al is oxidized. With increasing Cr‐addition and with increasing Ni‐content in alloys (Fe,Ni)3Al‐Cr the materials become more resistant, Ni3Al is not attacked by metal dusting.
The Initial Stages in the Oxidation of TiAl
Authors: Lang C. , Schütze M. 
Published: May 2005

AbstractThe oxidation behaviour of titanium aluminides containing 36 wt.‐% Al (Ti36Al) and 35 wt.‐% Al plus 5 wt.‐% Nb (Ti35Al5Nb) has been investigated by electron microscopic methods with emphasis on transmission electron microscopy (TEM). The oxidation experiments were carried out at 800 to 1000°C in laboratory air for 0.5 h to 4 h. In addition thermogravimetric measurements were made. It has been shown that the shortterm oxidation of TiAl can be divided into two stages. In stage I the preferred formation of aluminium oxide leads to an aluminium depletion of the metal subsurface zone and the subsequent formation of titanium nitrides which enhances the oxidation rate. After consumption of the depletion layer a repeated cycle of aluminium oxide formation, subsequent local depletion of the metal subsurface zone in Al and consumption of the Ti‐rich metal phase by nitride formation is observed leading to linear oxidation behaviour (stage II). In the niobium containing alloy the dissolution of alumina in titania is decreased and thus the formation of aluminium oxide at the metal/oxide interface is favoured. By electron diffraction it has been found that the aluminium oxide formed at the metal/oxide interface most probably is an aluminium oxynitride Al27O39N. The aluminium depleted metal phase has been analyzed to consist of α2‐Ti3Al and a new cubic phase with a composition between of α2‐Ti3Al and γ‐TiAl.
Untersuchung der Interkristallinen Korrosion bei Duplexstählen mit Thioacetamid als Aktivator im EPR‐Verfahren
Authors: Garz I. , Schultze S. , Göllner J. 
Published: May 2005

AbstractEs wird über Thioacetamid (TA) als Aktivator anstelle von KSCN zur IK‐Prüfung von Duplexstahl X2CrNiMoN22‐5‐3 mit Hilfe des double‐loop(DL)‐EPR‐Verfahrens berichtet. Bei vergleichbarer IK‐Detektion muß dazu die selective Ferritauflösung in der Prüflösung vermindert werden. Der gewalzte Duplexstahl wurde lösungsgeglüht und bei 650°, 750° and 850° 3 his 600 min isotherm belastet. Nach Prüfung in 0,5 MH2So4 + O,01 MKSCN bei 70° bzw. mit 2,5 × 104 bis 1 × 102 MTA bei 5° 60° und 70° erfolgte die Bewertung an Hand der Ladungs‐ bzw. Peakstromverhältnisse, metallografisch und mit REM‐EDX. Bei Nutzung der optimalen Parameter ist TA als Aktivator zum Nachweis der durch X‐ und α‐Phase hervorgerufenen lK von Duplexstahl geeignet. Die Wirkungsweise von TA wird diskutiert.
Korrosionsschäden am Förderband eines Ofens zur Reinigung von mit organischen Chlorverbindungen kontaminiertem Erdboden
Authors: Gawenda P. , Rahmel A. , Raths K. , Schorr M. , Schultz U. , Weiser A. 
Published: May 2005

AbstractEs wird das Korrosionsverhalten von metallischen Werkstoffen beschrieben, die als Komponente des Förderbandes eines Dekontaminationsofens zur Reinigung von mit chlorhaltigen organischen Verbindungen verunreinigtem Erdboden zum Einsatz kamen oder als Testwerkstoffe am Förderband befestigt waren. Insgesamt wurden 1 ferritischer und 8 austenitische Stäble, 9 Nickelbasiswerkstoffe, 2 Gußstahlsorten mit 15%, Si bzw. 15%, Si + 5% Cr sowie 3 alitierte Stähle getestet und anschließend metallographisch und mikroanalytisch untersucht. Die meisten der Werkstoffe versagten durch äußere abtragende und/oder durch innere Korrosion, bevorzugt entlang der Korngrenzen, ausgelöst durch aggressive Bodenbestandteile, insbesondere Chlorverbindungen.Als recht beständig erwiesen sich die beiden legierten Gußstahlsorten. Unerwartet gut hat sich auch der Werkstoff 2.4061 (LC‐Ni 99,6) verhalten, obgleich hier noch zu prüfen bleibt, ob das Einwandern von C und O an den Korngrenzen nicht eine Versprödung bewirkt. Sehr gute Beständigkeit zeigten die Werkstoffe 2.4610 und 2.4831. Die Gründe hierfür konnten nicht geklärt werden. Ein Grund könnte der relativ hohe Mo‐Gehalt von 14‐17 bzw. 8,5‐9,5 % sein, jedoch wurden andere Werkstoffe mit vergleichbaren Mo‐Gehalten wie die Werkstoffe 2.4856 oder 2.4663 stark angegriffen. Ferner bleibt zu klären, ob die gute Beständigkeit auch langzeitig erhalten bleibt.
Corrosion behaviour of highly alloyed stainless steels in mixed chloride and fluoride aqueous solutions
Authors: Bastidas J. M. , Fosca C. , Chico B. , Otero E. 
Published: May 2005

AbstractLaboratory weight loss and cyclic potentiodynamic polarization corrosion tests were performed on two types of corrosion resistant alloys, a duplex alloy (ferritic‐austenitic stainless steel) and two austenitic stainless steels, in mixtures of chloride (3000, 9000 and 15000 ppm) and fluoride (4800 and 15000 ppm) ions at pH 3. Two temperatures were tested, 60 and 70°C. The electrochemical results indicate that the duplex stainless steel presents high corrosion resistance. Weight loss results show low corrosion rates of the two types of stainless steels after 60 days exposure. Sonic pits‐crevices were found under the corrosion crust deposits on the duplex stainless steel.
Experimental determination of the Critical hydrogen peroxide ion concentration for titanium alloys in alkaline hydrogen peroxide solution
Authors: Hyökyvirta Outi A. 
Published: May 2005

AbstractThe first assumption was that titanium and its alloy should have excellent corrosion resistance in alkaline hydrogen peroxide bleaching. However, the pulp mill experience of the corrosion resistance of titanium alloy conflict partly with the earlier knowledge. The corrosion of both titanium and titanium alloy was studied in alkaline hydrogen peroxide environment. The cell was equipped with a water circulation loop and chemistry monitoring system. The monitoring system adjusted the pH‐value, hydrogen peroxide concentration and temperature of the solution.Both titanium and titanium alloy dissolved by uniform corrosion in passive state due to the hydrogen peroxide ion. This ion can destroy protective dioxide layer of titanium. The critical concentration of hydrogen peroxide ion could be estimated experimentally and for both titanium and titanium alloy it was 0.008 ± 0.008 M at 80 °C in alkaline hydrogen peroxide ion environment.However, theoretically based on thermodynamic no critical hydrogen peroxide concentration could be found whereas traces of this ion can attack titanium and titanium alloys. The experimentally determined corrosion rate of both titanium and titanium alloy seems to follow an exponential law as a function of hydrogen peroxide ion concentration, which could be explained by the Arrhenius equation.
Internal chlorination of Ni‐based alloys and its relation to volatilization corrosion
Authors: Tu J. P. , Li Z. Z. , Mao Z. Y. 
Published: May 2005

AbstractThe kinetics of internal chlorination of Ni‐based alloys between 400°C and 700°C were investigated by optical and scanning electron microscopy. Internal chlorination of Ni‐4Cr and Ni‐4Cr‐0.5Ce alloy occurred by formation of solid precipitates such as CrCl2, and CeCl3 which are thermodynamically stable and have low vapor pressures at the temperatures within the alloy matrix. In the lower temperature range, the kinetics of internal chlorination nearly followed a parabolic rate law. The degree of internal chlorination increased with increasing temperature. In the higher temperature range, the internal attack was accompanied by the consumption of the alloy by volatilization. When the rate of internal chlorination equaled the rate of overall metal consumption, the depth of the internal chlorination zone would approach a steady state value. At high temperatures, where vaporization was predominant, the steady state depth of internal attack was even smaller than that at lower temperature. When an alloy specimen was subject to little volatilization, it showed more internal attack than when it was not, and vice versa.
High temperature corrosion of low and high alloy steels under molten carbonate fuel cell conditions
Authors: Biedenkopf P. , Spiegel M. , Grabke H. J. 
Published: May 2005

AbstractThe corrosion behavior of eight low and high alloy steels was investigated under simulating the conditions at the cathode of a molten carbonate fuel cell at 650°C. Different Li‐containing iron oxides (LiFeO2 and LiFe5O8) were formed in contact with the eutectic (Li, K)‐carbonate melt depending on the Cr‐content of the steel. These oxides show low solubility in the melt and protect the metallic material against further corrosive attack last growing scales of Fe3O4 and LiFe5O8 were observed on the low alloy ferritic steel 10 CrMo 9 10. Higher alloy steels form LiFeO2 in contact with the melt and mixed Fe‐Cr‐spinels underneath. Steels with Cr‐contents over 20 wt.% Cr form a mixed LiCr1‐xFexO2 and LiCrO2 layer in contact with the metal. Marker experiments on the commercial steel 1.4404 (X2 CrNiMo 17 13 2) show that the outer LiFeO2 layer grows mainly by outward diffusion of iron ions (Fe3+), whereas the inner (Fe,Ni)Cr2O4 spinel layer grows inward. After 500 hours, LiFe5O8 was formed between the spinel and the LiFeO2 layer, but it had disappeared after several thousand hours of exposure as it was fully transformed to LiFeO2. Co‐containing LiFeO2 was found after 500 hours on the high Co‐containing steel 1.4971 (X12 CrCoNi 21 20), but is not stable after several thousand hours exposure. Co diffuses outward to form a protective LiCoO2 layer of a few microns in thickness. Protective Cr2O3 layers were not observed on steels with high Cr‐content (≥ 25 wt.% Cr) due to peroxide ions in the melt, which cause oxidation Cr2O3 and flux to chromate, which is highly soluble in the melt. Further quantitative investigations on total corrosion considering the chromate formation have shown that high alloy steels with high amounts of Cr form mainly K2CrO4.
Corrosion behaviour of Softmagnetic iron‐nickel alloys
Authors: Gehrmann B. , Hattendorf H. , Kolb‐Telieps A. , Kramer W. , Mottgen W. 
Published: May 2005

AbstractThe corrosion behaviour of different FeNi alloys containing between 35 and 82 wt% nickel has been investigated in a humidity test between room temperature and 80°C. It has been found that higher nickel contents improve the corrosion behaviour. The poor corrosion behaviour of the low nickel containing alloys can be improved by grinding and cleaning the surface. With approximately 40 wt% nickel and 8 wt% chromium a softmagnetic alloy has been found with a corrosion behaviour similar to a high nickel alloy with approximately 80 wt% nickel. This FeNiCr alloy achieves also approximately the same saturation induction of 0.75 T as the 80 wt% nickel containing Fe‐Ni‐Mo alloy. The sufficient low coercive force of less than 2.5 A/m after an appropriate heat treatment and the adequate corrosion behaviour make this alloy suitable as a material for stamped parts in electromagnetic relays.
The Atmospheric corrosion of statue bronzes exposed to SO2and NO2
Authors: Strandberg H. , Johansson L.‐G. , Lindqvist O. 
Published: May 2005

AbstractWe report on the atmospheric corrosion of different cast statue bronzes in humid air containing ppb levels of SO2and SO2+NO2. In addition, copper, tin, zinc, and lead samples were studied in these environments. The samples were exposed to synthetic atmospheres with careful control of pollutant concentrations, relative humidity and flow conditions. Deposition of SO2was studied using on‐line gas analysis. The weight gain was registered after four weeks exposure, and corrosion products were analysed by Electron Probe Micro Analyser (EPMA), X‐ray diffraction (XRD), and Fourier Transform Infrared spectroscopy (FTIR).The synergistic effect of SO2and NO2was remarkable on all bronze materials examined. The weight gain was correlated to alloy composition. Thus, high zinc and low lead content resulted in the greatest weight gain, while high tin content favoured a low weight increase. Lead exhibited a rapid deposition of SO2followed by zinc and copper, while tin was unreactive towards SO2. There was no measurable indication that microstructure influenced corrosion.The corrosion product morphology found in SO2+NO2environment indicated a localised type of attack. The anodic sites were covered by a tin‐rich corrosion product close to the metal. Oxidation of soluble divalent tin by O2at the anodic sites to form insoluble SnO2– xH2O, is suggested to explain the corrosion protection afforded by alloying with tin. Tin was enriched in the corrosion products while no lead was found. The zinc/copper relation was higher in the corrosion products than in the alloy composition.
The corrosion behavior of Fe‐Cr alloys containing Co, Mn, and/or Ni and of a Co‐base alloy in the presence of molten (Li,K)‐carbonate
Authors: Biedenkopf P. , Spiegel M. , Grabke H. J. 
Published: May 2005

AbstractThe corrosion behavior or commercial Fe ana Co base alloys and Fe‐Cr model alloys with different contents of Co and/or Mn was investigated by continuous exposure tests in the presence of a thin carbonate film. All alloys studied form multi‐layered corrosion scales consisting of outer Li containing oxides and inner Cr rich oxides, i.e. spinels or LiCrO2. The LiCrO2 is formed on alloys with high Cr contents (≤ 20 wt.%), whereas mixed (Fe,M)3‐x CrxO4 spinels (M = Co, Mn, Ni) were found on alloys with lower Cr content (15–20 wt.%). Insoluble Cr containing oxides occur only in the inner layers of the corrosion scale, whereas on the surface of corroded specimens soluble chromates were detected. Alloys with Mn contents greater than 15 wt.% form Mn2O3 in the initial stages of the experiments, this oxide reacts with the melt and formation of Li2MnO3 takes place. In exposure tests up to 500 h Fe‐Cr alloys with low contents of Mn and Co (10 wt.% Co or Mn) form iron rich oxides (LiFeO2 and LiFe5O8) with varying amounts of dissolved Mn or Co. In the later corrosion stages outward diffusion of Mn and/or Co takes place and LiCoO, and Li2MnO3 are formed on top of LiFeO2, whereby the concentration of Mn and/or Co in the inner layers (LiFeO2 and spinel) decreases. The outer Li containing oxides LiFeO2, LiCoO2 and Li2MnO3 are nearly insoluble in the melt and when present at the surface protect the metallic material from further corrosive attack. Fe‐Cr model alloys containing Co and Mn form multi‐layered corrosion layers after 2000 h of exposure. These layers consist of four oxides in the following sequence from the metal‐scale to the scale‐melt interface: (Fe,Cr,Co,Mn)3O4 spinel, LiFeO2, Li2MnO3 and LiCoO2.
A study of the Ag(s)/Ag2SO4(l) high temperature reference electrode
Authors: Lee S. , Staehle R. W. 
Published: May 2005

AbstractAg(s)/Ag2SO4(l) reference electrodes for use in hot corrosion research were fabricated and their properties were studied at 927°C (1200°K). The McDanelTM MV 30 mullite tube was used as sheath of the reference electrode and concentrations of the tested electrolytes were varied from 0.1 to 10 m/o Ag2SO4 (l) + Na2SO4 (l). 10 m/o Ag2SO4 was always used as electrolyte in the reference electrode. The working electrodes with less than 2 m/o Ag2SO4 showed marked potential drift as the Ag2SO4 concentration was lowered, showing poor potential stability. However, the initial values of cell voltages obeyed Nernstian behavior for all range of Ag2SO4 concentrations in the working electrodes, which showed that Ag(s)/Ag2SO4(l) electrodes behaved reversibly. Galvanostatic polarization was performed on a pair of 10 m/o Ag2SO4 reference electrodes to test the reversibility. The polarizability was 3.5 mV/10 μA with no hysteresis loop on the polarization curve, showing that the reversibility was satisfactory. The potential of gold electrode in molten Na2SO4 was measured under pure oxygen atmosphere with 10 m/o Ag2SO4 electrode as a reference potential. The results showed that the potential of gold electrode could be explained by the 2 Na + SO3 + 1/2 O2 → Na2SO4 cell reaction.
Mechanik der Brucherscheinungen in festen Körpern
Authors: Hahn Hans Georg 
Published: May 2005

AbstractEs wird gezeigt, wie eine theoretische Beschreibung der Bruchvorgänge in festen Körpern mit kontinuumsmechanischen Methoden möglich ist. Die beiden Haupttypen von Brucharten, spröder und zäher Bruch, sind eng mit dem Werkstoffverhalten gekoppelt. Als Grundlage einer Bruchtheorie für spröde brechende Materialien dient das Gleichgewichts‐ und Ausbreitungsverhalten von Rissen. Für den zähen Bruch in Metallen liefert die Berücksichtigung plastischer Gleitvorgänge einen Rißausbreitungsmechanismus, der sich von dem der Rißausbreitung beim rein spröden Bruch wesentlich unterscheidet. Die Anwendung der Erkenntnisse dieser Bruchtheorie zusammen mit versuchsmäßigen Ergebnissen führt zu einer praktischen “Bruchmechanik”, die bereits einen weiten Anwendungsbereich hat. Darüber hinausgehende Weiterentwicklungen zu einer allgemeinen theoretischen Erfassung des zähen Bruches sind heute noch nicht abgeschlossen.
Aussichten für die Entwicklung technisch nutzbarer faserverstärkter Hochtemperaturwerkstoffe
Authors: Elßner Gerhard 
Published: May 2005

AbstractIn verschiedenen Bereichen der Hochtemperaturtechnik werden neuartige Materialien benötigt, die sowohl hohe Zeitstandfestigkeiten und günstige Thermoschockeigenschaften aufweisen als auch in sauerstoffhaltigen Verbrennungsgasen oder ruhender und strömender Luft oberhalb 1000°C eingesetzt werden können. Unter Berücksichtigung der von der Technik gestellten Anforderungen werden die Aussichten abgeschätzt und überprüft, die auf diesem Gebiet für die Entwicklung leistungsfähiger Faserverbundwerkstoffe aus vorhandenen und zu entwickelnden Materialkomponenten bestehen. Es wird ein Überblick über vorliegende Verfahren zur Herstellung derartiger Verbundwerkstoffe gegeben und bekanntgewordene Versuchsergebnisse an potentiellen Faser Matrix‐Kombinationen kritisch diskutiert. In diesem Zusammenhang werden Fragen der chemischen Verträglichkeit der Verbundwerkstoff‐Komponenten eingehender besprochen. Diesem Problem und dem der Oxydationsbeständigkeit der Materialkombinationen muß bei der Entwicklung neuartiger Hochtemperaturwerkstoffe besondere Aufmerksamkeit geschenkt werden.
Werkstoffe und Schichtaufbau bei Gleitlagern
Authors: Roemer E. 
Published: May 2005

AbstractDie wichtigsten Legierungsgruppen von Gleitlagerwerkstoffen auf Pb‐, Sn‐, Cu‐ und Al‐Basis, teilweise mit galvanischem Überzug, werden besprochen. Neben der Angabe einiger physikalischer und technologischer Kennwerte wird besonders auf den Einfluß des Aufbaus von Verbundwerkstoffen im Hinblick auf die Gebrauchseigenschaften eingegangen. Einige Versuchs‐ und Erfahrungswerte werden angegeben, die als Hinweise für die Anwendung dienen können. Auch neuere Entwicklungen werden erwähnt.
Die Rißzähigkeit von Vergütungsstählen
Authors: Hellwig G. 
Published: May 2005

AbstractEs wird eine Übersicht über Ergebnisse neuerer Rißzähigkeitsmessungen an Vergütungsstählen gegeben. Die Einflüsse der Wärmebehandlung, der Prüftemperatur sowie metallurgischer und struktureller Faktoren auf die Rißzähigkeit werden aufgezeigt. Allgemein gültige Gesetzmäßigkeiten werden herausgestellt und dieKIc‐Werte kennzeichnender Vergütungsstähle bei Raumtemperatur zusammengefaßt.
Schichtverbundkombinationen aus hochschmelzenden Metallen und Oxiden
Authors: Elßner G. , Pabst R. , Puhr‐Westerheide J. 
Published: May 2005

AbstractDurch Hochvakuumverschweißung bei Temperaturen oberhalb 1400 °C werden Schichtverbundproben aus den Metallen Nb, Nb‐1 Zr und Ta und aus den Oxiden Al2O3 und ZrO2 ohne Bildung von zusätzlichen Zwischenschichten hergestellt. Mo und Al2O3 werden über eine Nb‐Schicht miteinander vereinigt. Die untersuchten Schichtverbundkombinationen sind von technischer Bedeutung für die Entwicklung von Verbundwerkstoffen und von hochtemperaturbeständigen Verbindungen zwischen metallischen und keramischen Materialien. Es wird über ihr Gefüge, ihre Eigenschaften und die chemische Verträglichkeit des Verbunds berichtet. Darüber hinaus wird eine bruchmechanische Methode beschrieben, mit der die Festigkeit des Verbunds über KIc‐Faktoren charakterisiert werden kann.
Die Faserverstärkung von Aluminium
Authors: Nixdorf J. 
Published: May 2005

AbstractDer Leichtbau benötigt Werkstoffe mit möglichst hoher Zugfestigkeit und hohem E‐Modul. Es liegt daher nahe, auch auf Leichtmetalle, vorzugsweise Aluminium, das Prinzip der Faserverstärkung anzuwenden, wie es beim Kunststoff breiten Eingang in die Praxis gefunden hat. Die unidirektionale Faserverstärkung von Aluminium kann durch Lang‐ oder Kurzfasern vorgenommen werden. Für beide Fasertypen sind unterschiedliche Technologien entwickelt worden. Die bisher bei Langfaserverstärkung erzielten mechanischen Eigenschaften ermöglichen die Entwicklung eines Hochleistungsverbundwerkstoffes für spezielle Anwendungen. Die Einlagerung möglichst preiswerter Kurzfasern sollte dagegen vorzugsweise für die Herstellung eines Massenproduktes für breite technische Anwendungen entwickelt werden.