DE1646689A1 - Corrosion-resistant, heat-resistant sintered material - Google Patents

Description

Dr. Ing. Hj. Ν. Blacks. . . _ Patent attorney I I J-m * Τ-7τ * · * ν1

415 KREFELD [ LJl. J3XD1.

Westpa rkstr. 14 - Tel. 2667t .. ..ij

IfETALLWERK PLANSEE AKTIENGESELLSCHAFT

Beulte / Tyrol ■ ·. 1646689

. Corrosion-resistant, warefeater sintered material

In various branches of industry, there is an increasingly urgent need for materials with good corrosion resistance to aggressive, in particular overheated, metal oxides. In addition, good corrosion resistance even noob high demands on the laeohanieehe strength and Teaperatumeohselbeetündigkeit such materials are often provided · For some purposes is also Nooh good elektrisohe conductivity demanded "Anwendungsbelepiele for these materials are * · Β · Verdampfereleaente that for evaporating Metallcohaelsen la Vacuua serve «whereby the heating through direct

BATH ORIGINAL

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Stroadurohgang before genoaaenwird · As works for Verdaapfareleaente sue have evaporation of aluminum elements see Titanium boride and Zirkondiborld old small additions of chromium boride relatively well proven · Also sintered material · on the bast "of boron nitride" have proven to be suitable to a certain extent for this purpose.

Recently, an attempt has been made to use aluminum nitride as a corrosion-resistant material. Ss has declined that sintered form bodies made of aluminum luanitride, the nor impurities or additions of silicon nitride, boron nitride and cryolite!

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excellent resistance to metal slacks, ζ · Β. Aluiainiua- • sohaelsen, Iron soles, etc., has. Xn restrictedoa The scope is therefore aluainluanitride »or the manufacture of crucibles, Oluhsohiffchen, stove stones, etc. used. The size Sprttdigkelt and a lack of temperature change resistance of Aluaioiuauitrids has hitherto been a broader one Application contrary · Since Alnainiuanitrid auilerdea an electric Is insulator, it can be used for aanohe purposes, see B. for evaporation elements, which are heated by direct passage through the stream, are not used for this reason. According to The present invention now succeeds in producing an aluminum nitride content Sintered material su create the properties of previously known kuurpera from Aluaioluanltrid does not show.

Qeganstand der Erflndong 1st deanaeh "in Aluainluanltrld ent" *

S *

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holding »corrosion-resistant» waraf-proof sintered material which in addition to a high level of resistance fKiiigke It ge & eu Metal isoiitBelzen good «aeeUanlsohe Rlgenechoften ur <3 one good toapornturtteohsolbeistündlkeit

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The new material contains 40 to 97 vol. #, preferably h5 * le 60 vol.

Under 'Koaponentea bit "metallic conductivity" within the meaning of the invention * not only for the purposes of the invention, "oncfern also the compounds defined under the new' metallic hard substances *; we understand" the electrical aetallic quality "that is, relatively good and effective through a positive electrical teaperiod Awaken your weakness. The aluminum nitride content, which, according to the invention, is between 0 and 97 vol., Preferably between 45 and 50 vol »Is 3 Vol, i? _t vorpiujewcioe 55 to 20 vol. metallic components of the material, the respectively required aeohanleohe strength and temperature change limit on Oründ beseerer WUroelοitfHhlgke11 gives "all metallic components oign ^ n inherent in the high-end, molybdenum and molybdenum metals

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one or more of the baskets and / or dorldo of the metals Molybdenum or / or tungsten; as well as the carbide, boride and / or nitrides of the metals titanium, zirconium, hafnium, vanadium, niobium, tantalum and chromium the inventive effect is also achieved when the aluminum nitride powder used up to 25% of its weight Silicon carbide, silicon nitride, aluminum oxide, boron nitride and other things as additives or impurities in Commercially available aluminum nitride powders contains.

Dl · production of the inventive material takes place sweckm & Oig using known powder metallurgical methods through fine grinding of the powdery Auegangtikosporients,

Pressing moldings at a pressure of approx.Q ₉ H up to 3 t /

2
cm, if necessary post-processing of this body according to a possible Voreinterung 700-1300 ° C in a non • xifttUerendor atmosphere and then Fertigainterung in a temperature range from 1600 to 2300 ⁰ C in a non-oxidizing AtmosphUr ·· advantageously is dl · presence of nitrogen or ammonia in the Furnace atmosphere & ro during high sintering,

Ib with regard to the type of metallic components The very different character of the aluminum nitride, it is surprising that the compositions according to the invention are extremely easy to sinter, so that even without the use of the for the production of pure aluminum foil bodies mostly drawn in · printing procedure relatively diohte

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Molded bodies can be obtained. For dl "Foragebunf know other known methods such as Strtmgpresnen tin <t slip" GU0 _t applied who «lon. Likewise, it is of course also possible to use the heat exchanger, the powder mixtures being sintered for example in a graphite form with simultaneous application of a pressure of 40 to 200 kg / cm at temperatures between 1600 and 300 ° C.

In a further embodiment "for" of the invention, the nitrides, partially or entirely the metal in question or their hydrides, are incorporated and sintered in nitrogen or ammonia-containing atmosphere in the kit. changed. Furthermore, there is the requirement that, instead of the net unfavorable substances, the elements, of which the substance is made, are used in the reception (aD V -f C dividing of WC) and the formation of the desired substances hurriedly caused by the sintering process. Instead of the element of the fabric, such compounds of this element can also be used which have the usual neutral material on the sintered curtain. the unfamiliar! iartstoffgesisohe result

The sintered ForakHrper can, if necessary, smooth still processed by grinding to close tolerances

"Earth" some types of execution of the material according to the invention " like ζ · Β · dl «2usaamcnBetsungcn Alunlnluanltrld-, can also be machined «

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The use of d ·· erfindtingsge "UQen fferkstoffee koant particularly into account, call it offered simultaneously

raised requirements for Aoohan festival circles and Tereperntur «« Chftel resistance to an · excellent corrosion resistance, in particular with regard to sohnelzflUselgcn lietallea, ankoaat. The new materials »I have for example for crucibles, Theraoeleaenteo hat »tubes, AusgnO · pots for the 8-strand process, for valves and PUsencleate » Puapenbe «taodteils Verdnapfereleaento and others not Corrugated metals in the ocher are good for parts proven

The electrical conductivity of the new material proves to be very beneficial for aaoohe application. By appropriate selection share dee the aetallieohen Koaponenten, the electric vfidtrstand held hüher "ground than in the binher verwendoton Uerkeiorfeo for Verdompfereleaiente based" on carbides UUD Borideti "Au" serve "Qrunde can at the same% current evaporator elements ait verhältnienäßig large cross sections eingesetKt" earth, which results in a longer service life «

On arund the adaptability of the electrical resistance ktfnaoü Verdaspferolenente from the inventive material even without special tJebnutan and changes in the trnneforaatoren Installed in ready-to-use emergency systems which, for example, refer to the operation τοη Oraphltver-

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evaporate or thin-walled ffolfrna ·, Uetailknrbld- or metal boride Verrtuapforn »uagclegt» ind.

The invention is explained in more detail on the basis of the following examples. At the ones in the valley percentages contained are »lon consistently a un weight percent. The temperatures are in Celelus Grqden specified

Example Xt 60 Jt Aiuaiaiuanitridpulver handeleüblicher purity ait 2 £ alumina was old in acetone ground hO $ powdery "Tltnndlhorld 20 hours in KugelaHhien with Iiartmetnllkugeln and after addition of 2 £ paraffin under lüinren dried · From the Mlechung were at a pressure of about 1300 KSS / c »Bltfoke pressed and pre-hardened at approx. 1100 °» Aue the blocks were then evaporator pieces with the dimensions 15 Br χ IJ and 115 BB and sintered in a tungsten tube furnace at 2050 ° for 20 minutes in AsnaonlakatBoephur. Oils evaporators have a specific weight of 3, b g / approx ⁵ and a specific electrical ttlderxtnnd of approx. 2500 micro-ohms. They were used in a vacuum draining plant for hole vacuuming old aluminum, which was fed continuously in wire form. Ea kounte about the β bla 10 times the aluminum standard Ib compared to the previously used vaporizers can be vaporized on the Baal «aged Tllandiboridt ·

Belepiel 2t 75% Aluslnluanitridpulvor old one "tcinlieitögrad of 99% was 25 Jt pulverfttruigen ZlrkonluBdlf> ORID _f

109847/1375

BATH ORIGINAL

~ ^β ~ 1646683

as described in Example 1, milled and dried · From Were you the pre-sintered at about 1000 · ⁰ C freQlIngen! Herausgeforat melting pot and oa · 2000 ⁰ C in oven Onea old WoIfraaheixleltern · sintered in reinster Stickstoffataosphäre In Schaelztiegelη Alualniua, Alualniuasllisiualegierungen and steel "were smelted chiselxen different Zusaaaeneetzung. Even after many years of use of the crucibles and long exposure to the melts, practically no attack on the Sohaelx crucibles could be detected.

EXAMPLE 3 65 % aluminum nitride powder old elnea purity of about £ 95, the remainder essentially consisting of silicon carbide and aluminum oxide, titanium diboride and 3 £ chroadiboride, as stated in Oeisplel 1, were ground, dried and blocks betrayed. From the "% pre-sintered blocks evaporator rods with the dimensions 10 χ 10 χ 60 aa were cut out and ^{sintered at 2100 0} O in aaaonia-containing, oxygen-free atmosphere. The sintered evaporators showed a specific weight of 3.4 g / cm * and an epee, electrical resistance of approx. 800 micro-ohms «approx.

Example% s 80 ^ aluainluanitride powder, 15 % zirconia world powder and 5 % taatallboride powder were as in Example 2

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specified, processed. Crucibles made from it showed excellent resistance to tendon fluids Light metals and non-ferrous alloys as well as steel melts of various Kuraam compositions

Example 51 40 parts of aluminum nitride, old oa. 2 % alumina, 2 % silicon carbide and 1 % sillzluanltrld; 45.2 parts of titanium hydride and 16.7 parts of boron carbide were milled in acetone for 12 hours in acetone using ball mills . Because of the reaction of titanium hydride and boron carbide, the hot-pressed material consisting of 40% aluminum nitride, 42 $ Tltandiborid and 18 1 "titanium carbide · BR heifigepreOtea plates were after grinding to tolerance means Dlaaantsoheiben for the production of the valves was used" which proved to be much more durable al * all materials used so far proved

Example 6t 50% and 50 Aluniniuanltrldpuiver $ MolybdÜnpulver was quoted commended in Kugeleühlen old dry steel balls and pressed in corresponding Ouaaiformon hydrostatically Theraoeleaentschutzrohren and sintered at 2100 ⁰ C in a nitrogen-containing atmosphere of hydrogen. The sintered parts were machined to tolerance on a lathe using hard metal tools and then sar Teaperaturaessung alt Platln / Platia-Qhodlua-Theraoele-

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aents are set in steel bulk melts of mixed compositions They were found to be excellent on the face of it Corrosion attack and unavoidable TheraoscUoekboan spell gene,

Example 7s hO% Aluainlunnitridpulver and 60% tungsten powder were trie in Example 6, processed into TheraoeleBenisehntsrobren and Stableehaelzen tert ^ ohiedener Zufl "" nensetsung ■ li as good "success ·" it, used as described in Example 6. FIG.

Example β: 40 great aluminum nitride, 19.3 parts aluminum metal powder, 12.1 parts titanium hydride and 15 parts titanium diboride powder were ground wet & in petroleum ether using spheres of glass, dried according to 1% paraffin and given oval shapes hydrofitatlsoh sn thersoolesientschutxrohren pressed. The sintering took place slowly and slowly in oxygen-free nitrogen gas at 2120 ° C in an electric oven with old wolf rods. Due to the reaction of the Aloaialua- and TltnnhydrldpulTora old nitrogen contained the sintered Forakurper 70% aluminum, 15 Ü? Itnndlborid and 15% titanium nitride. Pie Thera elementary tubes were used in copper and brass casings, as well as in steel sheets, which have been very successful in the past.

Example 9t 40 $ aluminum nitride, the silicon nitride 1 «Uo-

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ratio AiK t SiG m * ti, hit 30 % llolyfedlnpulver, 20 % tfolfraapuiver and OK it zirconiumltridpulver, according to the example 8, Jedooh using other CUuIfOrMB ₁ su pouring stopper for a steel rod filling plant processed. eich with regard to "a corroeioneboattdlgkeit and TevperattirveolieeibeMtiindeit all so far for dleeen £" eok elnseeetxteB material tea erbeblioh ttberXec "> n.

Beiepiei 10t Aliminluanltritl 72%, the 6 i Slllxluakarbld and 6 $ silicon nitride contained, bit 1%% zirconium »diboron""$ 8 !, Tea t aldibor id _t Tanadlndiborid 3% and 3% Nlobdiborid geaMS example were 8 veraableu and NaOH dea Trook · nen and NaOH addition of 0.5% Kaepfer su cylindrical Blttoken Terprettt · Kaoh he united ti sr: & m Vakuus at 1050 ⁰ C Sohaelstlegel were geforat and sintered at 2000 stole 20 ⁰ C in oxygen free Avaoniakataosnhäre from these Blttoken. The Seaawl crucibles were used for the evaporation of Aluaiaiuaj ia \ aoehvakkum by means of an electron beam and also did not cause any attack,

BAD .ORIGINAL 109847/1375

Claims (1)

Patent claim rH eh i. Corrosion-resistant, heat-resistant sintered material with high resistance to molten metal, with an aluminum nitride content, characterized in that it is 40 to 97% by volume, preferably 5 to 80% by volume Contains aluminum nitride and the remainder with components metallic conductivity, which have melting points, that are above the melting point of pure iron * 2 »Sintered material according to claim 1, characterized in that that it is 3 to 60 Volr #, preferably 20 to 55 Volr # • One or more of the metals chromium, molybdenum and Wolfra · contains. 3 · Sintered material according to claim 1 or 2, characterized in that that it contains one or more of the carbides and / or borides of the metals molybdenum and / or Wolfra. k. Sintered material according to one of Claims 1 to 3, characterized in that it contains one or more of the curbs, borides and / or nitrides of the metals titanium, zirconium, hafnium, vanadium, niobium, Tuntal and Chroo. 5 · Sintered material according to one of claims 1 to 4, characterized by the fact that!) The aluminum nitride contains up to 25 % of its weight in silicon carbide, silicon nitride, aluminum oxide, boron nitride or other additives or impurities 10 9 8 4 7/1375 commercial Alualniuanltrldpulveru vorkoaaonde Contains substances » 6, procedure * ur iferatellation «in ·« Slntemerke toffee neoh • In · «dor claim« 1 to 5, datlurah marked, daO il vorsugavelee under Zueota an orßaniachen liquid . Celtic finely ground Auagangepulver, optionally after introducing "in ·· preOerleienternden Zuaatiea in push ·" χ "1ϋο1ι · η 400 UUD 3,000 kg / oa verpreflt w" approximately "n _v Dao manufac" niing · after gege benon fall nUoben 700 and 130o ⁰ C In non-oxldi "r" nd "r Ataoapttfr" Yorgeaintert and elnar "ftit" r "n Foregeliung are subjected, whereupon the fora" body swiaohen 1600 and 230O ⁰ C in non-oxidizing atmosphere, torsionally in atickatoif- or _λ haitiger ataosphere _(to be fully aged » 7 » ^v erfabrtB aach Aneprneb fc, dadureh marked, YM ie · la Verkcteff gewUnaehtea Nitrftde« «I« Mtalliaekea . IeaBe «e» tea Ia rom pure metals eder m Metikllhydrli ·· •! ■ «•• tilt mi gates · 4 ·· SlMem in etleketeff * e # er • wmiuiaaitlger Ata ·· »Hire U die ifltrli · i * «Trie». •• TerfAhrtt iiilAMfmhi eder 7, daderea ketaatlebnet, ia · fm $ tu in the material geeUaeokteii garbleea «ni lerUta either eleaentare leatondteile or Yerblndungea tingeeetst« ad iareh flnterfreiet Ib the final fera 109847/1375 To be transferred " 9 * A method according to a "4-b claims bie β, characterized dndureh, daö to Fomgebuag anateil · dee Ver · preaaona ice SohliekerguOverfahren is angeweadet" OK «procedure nnoh one of the tests 6 bit 9, thereby characterized that the rerwgebtittg by »traagpr ·· - een is preceded with pla * tifying additives ti «procedure aach eine» der Aaepriiche 6 toi · 1O ₉ -iaduroh gefceaazelkom / daft the vacation and d * a sinter at the same time by ilclOpreaawa at Teei> trntnr * n cwl · eeaea 1600 and 2300 ⁰ C «ad DrUokea zviaehea 40 aod kg / e · Torgeneaaen will. it * Αβ · a · sintered material according to the standards 1 bia ι, dare · dlrektea itvmalareligemf «rkitaamraa «M TwMMWtM WwB AtMwIaUaV t» ■ * '' BAD ORIGINAL 109847/1318