NL8120396A - Laminate for use in contact with molten glass - comprises refractory metal substrate enveloped in precious metal and isostatically hot pressed - Google Patents

Abstract

Laminate for use in contact with molten glass comprises a substrate of refractory metal and a first layer of metal impermeable to oxygen. The substrate and layer are intimately bonded together by hot isostatic pressing. The refractory metal is selected from Mo, Nb, Hf, Ti, Cr, Ta, Zr, W, Re, Mn and their alloys and the metal coating is a precious metal selected from Pt, Pd, Ir, Os, Rh, Au, Au, Ru and their alloys and it surrounds the refractory metal completely. The coating is made to conform with the substrate and to present oxygen-impermeable walls around the substrate, is sealed around the substrate, then isostatically hot pressed to bond the coating intimately to the substrate. Laminates in both simple and complex shapes may be prepared when the coating is sintered onto the substrate with the aid of isostatic pressing. The coating is relatively thick and more difficult to penetrate by damage than vapour deposited and other coatings of prior art. The tools obtained have improved mechanical strength and will resist temps. of up to 1900 deg.C.

Description

* 4 pct / N-30.9 84-tM / f. 8 1 2 0 5 9 6

Description.

Objects for touching molten glass.

Technical area.

The invention described herein relates to a metallic laminate, which consists of a refractory metal-shaped substrate, which is provided with an oxygen-impermeable precious metal layer, which is intimately bonded thereto by the fact that the precious metal formed layer is hot isostatically pressed onto the refractory metal substrate. Some of the objects produced thereby can operate at temperatures above 3,500 ° F (1,927 ° C).

Background art.

The need for articles to operate in high temperature environments, especially articles used in connection with molten glass, has made many attempts to coat refractory metals, such as molybdenum and tungsten, with platinum and platinum-based alloys. As is known in the art, these refractory metals oxidize quickly at high temperatures, but they have a significantly higher strength at these high temperatures when kept in a non-oxidizing atmosphere. However, platinum and platinum-based alloys are relatively unreactive at such high temperatures, but they have a significantly lower operating temperature limit.

Early attempts to produce an article that exhibited the strength properties of the refractory metals and retained the unreactive nature of the precious metals have produced a number of techniques and combinations. Some of the earliest attempts provided non-laminated systems. Thus, loose fitting plates of the precious metals were placed over refractory metal cores. In some cases, an inert gas was supplied to the space between the plate and the core. See, for example, U.S. Patent 3,730,109, issued May 29, 1973. These enclosed objects were troublesome, did not take full advantage of the desired properties of the refractory metal or the precious metal eri had a number of other constructional and mechanical problems associated with it.

Sandwich rolling provided a laminate in which the platinum was bonded to the molybdenum. However, only relatively simple shapes could be produced and the edges of the laminate left the refractory metal exposed to the atmosphere; further, since the two layers were rolled together, cracks were formed quite often on the intermetallic bond zone, which was formed by the diffusion of the molybdenum and platinum into each other.

Other techniques, such as electroplating and plasma spraying the platinum layer on the refractory metal substrate, allowed production to be somewhat more complex. However, only very thin platinum coatings could practically be applied and these platinum coatings were generally porous in that they had a number of holes. With these holes in the outer layer, oxygen was still able to penetrate the system and attack the refractory metal substrate, rendering the laminate unusable for high temperature applications in an oxidizing atmosphere. The lack of success with these early attempts is also shown in U.S. Patent 3,657,784. This is especially true with regard to molybdenum-25 cores and platinum coating. To solve the problem, this patent uses a "getter", for example titanium or zirconium, and a barrier layer of prescribed refractory compounds, for example, MgO.

The present invention provides an article which is generally free from structural defects and has a relatively thick oxygen-impermeable precious metal outer layer which is intimately bonded to a refractory metal substrate to form a laminate of good provide high temperature usability. The laminate is conveniently and economically produced by a technique that surprisingly avoids the need for the use of costly barrier layers. Furthermore, it appears that these laminates are better than those obtained with ion plating, sputtering, electroplating and simple mechanical compression.

8120396

1 lL

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There has been a long felt need to manufacture a long-life feeder for flowing out streams of molten inorganic material such as glass at operating temperatures higher than are currently used.

Much of the earlier work has focused on forming alloys with better properties than the alloyed metals. Textile feeders or solid feeders have historically been made from platinum and rhodium alloys. Wool or rotatable feeders are manufactured using cobalt-based alloys.

The present invention provides inorganic fiber forming feeders in which the strength properties of refractory metals at higher temperature are combined with the oxidation. precious metal resistance to produce feeders capable of operating at higher temperatures for longer periods of time than previously commercially viable.

Description of the invention.

This invention relates to an article consisting of a refractory metal substrate having an oxygen-impermeable precious metal layer intimately bonded thereto by the substrate and the precious metal layer is hot isostatic on to squeeze each other. These articles are extremely suitable as parts in numerous devices which operate in contact with molten or heat-softened glass.

This invention relates to a laminated wall for a feeder for feeding molten streams of inorganic material to be extracted into fibers having a refractory metal core which is an oxygen impermeable noble has a metal sheath intimately wound therewith by hot isostatic pressing, the wall having at least one opening extending therethrough to allow the molten material to pass.

8120396 yy -4-

Brief description of drawings.

Fig. 1 is a top view of a laminate during manufacture.

Fig. 2 is a side view of the laminate 5 at another point during manufacture.

Fig. 3 is a side view of the laminate after hot isostatic pressing.

Fig. 4 is a semi-schematic front view of a textile fiber forming system of the textile type.

Fig. 5 is a semi-schematic front view of a rotating fiber or glass wool molding system.

Fig. 6 is an enlarged cross-sectional view of walls with openings such as the power supply members shown in FIGS. 4 and 5.

Fig. 7 is an enlarged cross-sectional view of walls of apertured power supply members, such as those shown in FIGS. 4 and 5.

Fig. 8 is an enlarged cross-sectional view of a portion of the feeder wall of FIG. 7 with a hollow tubing section inserted therethrough.

Fig. 9 is an enlarged cross-sectional view of a supply wall, as shown in FIG. 7, with a hollow tubing portion mounted on the outside thereof.

FIG. 10 is a cross-sectional view of a feeder wall of a fiber forming system, as shown in FIG. 5.

Fig. 11 is an enlarged cross-sectional view of the center flange eyelet used in the system shown in Figs. 12 and 13.

Fig. 12 is an enlarged cross-sectional view of a portion of the feeder wall during manufacture with a hollow tube portion with a center flange inserted therethrough.

FIG. 13 is an enlarged cross-sectional view of a feeder wall according to the principles of this invention.

Fig. 14 is an enlarged cross-sectional view of a wall of a power supply with opening 40 as shown in FIGS. 1 and 2, 8120396-5.

Fig. 15 is an enlarged cross-sectional view of a portion of the feeder wall of FIG. 14 with a hollow tube portion inserted therein.

Best embodiment of the invention.

According to the principles of this invention, an article is produced having good strength properties at a higher temperature, which is useful at high temperatures in an oxidizing atmosphere. For the purposes of this description, the substrate or core is a refractory metal or blank. In particular, these refractory metals are selected from the group of materials consisting of molybdenum (Mo), niobium (Nb), tungsten (W), rhenium (Re), tantalum (Ta), harnium (Hf), titanium (Ti) , chromium (Cr), zirconium (Zr), vanadium (V), manganese (Mn) and alloys thereof. The coating 15 or outer layer is a precious metal or alloy. In particular, precious metals are selected from a group consisting of platinum (Pt), palladium (Pd), irridium (Ir), osmium (Os), rhodium (Rh), gold (Au), silver (Ag) and ruthenium (Ru ) and their alloys.

The most desirable compositions for the laminates of the present invention, in terms of the economics of manufacture, including material costs, and optimum operating characteristics will vary with the composition of the molten glass it is in contact with. Most desirably, the laminates are used as the apertured bottom wall of a glass feeder or tray. for molding glass fiber products from various glass-forming oxide compositions. Normally, the fiber products are formed at temperatures generally corresponding to those at which the molten glass has a viscosity between about log 2.5 and log 3 poise. It is common in the industry to refer to fiber-forming glasses having a temperature, where the glass has a log of viscosity of 2.5 and it is well known that most of the commercially produced glass fibers have a temperature that is corresponds to the log 3 viscosity, which is about 120 ° F (49 ° C) to about 1900R (88 ° C) higher than the temperature, corresponding to the log 2.5 viscosity. High grade glasses have 8120396 I x -6- with a viscosity of log 2.5 corresponding temperatures generally above about 2050 ° F (1121 ° C) and more typically above about 2250 ° F (1232 ° C).

Thus, the present invention is excellent for use as glass feeders for forming glass fibers not only of conventional E type glass, but also C, S and R type fibers. E-type glasses are generally known as low alkali-containing or at least substantially alkali-free alkaline earth aluminum boron-silicates and, with a viscosity of log 2.5, have corresponding temperatures between about 2300 ° F (1260 ° C) to about 2400 ° F (1316 ° C); these glasses usually contain less than about 1 weight percent alkali metal oxide and may contain small amounts, usually less than 1 weight percent, of fluorine. C-type fibers are alkali-containing alkaline earth aluminum borosilicates having a temperature corresponding to the viscosity (poise) of log 2.5 of about 2300 ° F (1260 ° C). S and R type fibers or alkaline earth aluminum silicates having a viscosity of log 2.5 have corresponding temperatures ranging from about 2500 ° F (1371 ° C) to about 2800 ° F (1538 ° C) depending on the specific composition. For example, that temperature for a calcium oxide aluminum borosilicate having small amounts (less than 1 weight percent) of alkali metal oxide is about 2540 ° F (1393 ° C) to about 2580 ° F (1416 ° C) while that temperature for a magnesium oxide aluminum silicate is about 2700 ° F - 2800 ° F (1482 ° C - 1538 ° C). Using the present invention, it has been found that feeder supply walls can be used which are much more economical compared to normal platinum or platinum rhodium alloys which have been used in the past since longer lifetimes will be obtained with less use of expensive platinum and rhodium.

The term refractory metal or metals as used herein refers to any of the metals of groups IVB and VB and VB and VIB (of the periodic table), rhenium (Rel and manganese (Mn), alloys mainly these metals exist and base alloys of one or more of these metals It will be understood that the alloy in this connection also includes the inclusion of normal 8120396 -7 impurities as well as the inclusion of conventional non-metallic materials, for example, carbon. refractory metals are W, Mo, Nb, Ta and Re Mo and W, including alloys thereof and base alloys of either or both, are excellent for use as the bottom wall of glass feeders in forming fibers from many of the common fibers high volume Representative of a preferred alloy is an alloy of Ti, Zr and Mo. Such a TZM alloy is a Mo-based alloy and contains effective recrystallization temp. erature enhancing amounts of Ti and Zr; although such alloys mainly consist of Mo, Ti and Zr, they may also contain carbon, nitrogen and small amounts of impurities.

These TZM supplies work well as feed hopper bottom walls in forming fibers from glasses (eg, magnesium oxide aluminum silicates of log viscosity of 2.5 at temperatures from about 2700 ° F (1482 ° C) to about 2800 ° F (1538 ° C). A particularly suitable TZM alloy will consist essentially of about 0.6% Ti, up to about 0.15% Zr while the remainder is at least substantially Mo, this alloy may also exhibit less than about 0.02% C and traces of oxygen, hydrogen, nitrogen, iron, nickel and silicon.These TZM alloys with respect to Mo show improved hot strength and resistance to recrystallization and are available from AMAX Ine.

Another alloy suitable for many applications is the so-called Fan-Steel materials, such as the alloys, which mainly consist of Nb, Ta, W and Zr; they are mainly Nb-based alloys and more particularly FS-85 material is not exemplified.

The precious metals include Au and Ag as well as the so-called platinum metals, namely Pt, Pd, Ir, Rh, Ru,

Ox and its alloys. Pt and Pt-Rh alloys were and still are materials that are used at least virtually commercially as feeder bottom walls. It has been found that, according to the present invention, these precious metals, for example Pt and Pt-Rh alloys, can now be used more economically for manufacturing feeder trays which have higher strength at high temperature, greater creep resistance and thus greater resistance against sagging.

8120396

4 I

-8-

The importance of this will easily become apparent.

Depending on the desired object properties, the substrate and sheath materials can be chosen to optimize the system for a number of parameters such as strength, durability, creep resistance, temperature usability and price.

To produce preferred laminates, care must be taken in preparing the surfaces of the substrate and the precious metal layer. Impurities on the surfaces of the substrate and the first layer, which must be intimately bonded together, can seriously affect the cohesion of the laminate. These surfaces must be cleaned with conventional techniques.

Once these surfaces have been thoroughly cleaned and dried, the substrate and the first layer are placed together and are ready to be hot isostatically pressed or subjected to a "HIP" treatment in a conventional isostatic pressing system. The abutting surfaces generally must match to obtain a good connection between the layers.

As is known, isostatic pressing is a technique whereby an object is subjected to a high temperature while being held under uniform pressure from all directions. In operation, a chamber is pressurized with an inert gas or fluid, such as argon, to ensure an even (isostatic). pressure is obtained and heated by means of electrical resistance elements located therein. Preferably, the applied HIP temperature should be less than the recrystallization temperature of the core and the HIP pressure should be greater than the tensile limit of the casing material at the selected HIP temperature.

In order to produce a more convenient article with a refractory metal core completely surrounded by a precious metal shell, several other processing steps are desirable. The refractory metal core must be fabricated to the desired shape and the precious metal shell must be formed to fit the outer surface of the core precisely. The core and shell must be thoroughly cleaned 8120396 • * -9- and then the core must be slid into the shell. While at least one edge or seam of the sheath remains unclosed, the sheath containing the core must be degassed hot under vacuum. Hot vacuum degassing consists of heating the core and the casing to a high temperature in a vacuum for a time to remove any residue or other impurities from the cleaning operations.

According to the degassing treatment with heating and under vacuum, the remaining unclosed rim or edges of the envelope must be welded together to hermetically seal the envelope about the core. These edges are preferably welded with an electron beam, since this welding takes place in a vacuum. However, welding with a laser beam can also produce an acceptable object if this is done in a vacuum.

Following welding of the last edge, the casing should be checked for leaks or porosity. One such test consists of subjecting the object to gas pressure in a chamber, for example, about 6,250 psi (1.72 x 10 N / m) for 1 to 2 hours. When removed from the chamber, the object is immersed in an alcohol bath. If pores are present in the shell, bubbles will appear in the alcohol.

Assuming that the article has passed the leak check test satisfactorily, the article is ready to be hot isostatically pressed to intimately bond the casing to the core. Proper HIP treatment will provide a metallurgical or diffusion connection.

In addition to simple hot glass-contacting plates and rods such as are found in glass fiber feeders, complicated models such as rotors for progressive cavity pumps, stirrers and electrodes can be fabricated using the laminated or coated structure according to the present invention .

In order to obtain a desired article consisting of a core of a molybdenum alloy, especially an alloy of molybdenum, titanium and zirconium known as TZM, which is coated with a platinum based alloy, 40 the HIP process should preferably have the following parameters. 8120386 -10- am. During the HIP process, the temperature should fall within a range of about 2200 - 2400 F (1204 ° C-1316 ° C). However, the temperature should not exceed the recrystallization temperature of the TZM material, which is generally within the range of 2200 ° F to 3000 ° F (1204 ° C - 1649 ° C) depending on the degree of cold working of the TZM alloy . The applied pressure must fall within a range 7 from about 10000 to about 15000 pst (6.89 x 10 x 2 8 2 N / m to about 1.3 x 10 N / m) and the object must be at these temperatures and pressures kept for a period of 1 to about 3 hours.

In order to obtain plates suitable for incorporation into a glass fiber molding feeder, the plates or shell consisting of platinum or a platinum-15 alloy must be oxygen impermeable and have a thickness between 0.005 inch (0.0127 cm) to 0.030 inch (0 , 0762 cm). However, thinner or thicker plates can also be used.

As for the chemical pretreatment of the core and shell materials to clean the surfaces, it has been found that for platinum and platinum-based alloys, immersion of the shell in king water for 20 minutes at 350 ° F (177 ° C) produces acceptable results. Thereafter, the casing must be rinsed in water and then in alcohol and air dried.

As for the refractory metal substrate, e.g. TZM, it has been found that immersion of the core in an acid bath consisting of (by volume) 2.34% of 95-98% sulfuric acid, 15.63% of 69-71% nitric acid , 35.16% of 99-100% acetic acid, 35.16% of 85% phosphoric acid and 11.71% water for 6 minutes at room temperature is sufficient to clean the surface of the core. After immersion in the acid bath, the core should be rinsed in water and then in alcohol and then air dried.

It can be seen from Figs. 1, 2 and 3 that a frame or frame 2 is placed abutting the side edges of the core 1, which is in plate form. Precious metal strips, preferably the same material as plates 3 and 4, can be welded together to form the frame. The thickness 40 of the frame 2 should at least be substantially equal to the 8 1 2 0 3 f? $ -11- thickness of the core board .1 as shown in Fig. 2. The core .1, frame 2 and plates 3 and 4 must be cleaned as previously set forth herein.

Then, the core 1 with the frame 2 placed around it is received between a first precious metal plate 3 and a second precious metal plate 4, which are preferably of the same material.

Then all edges of the plates and frame except at least one edge are welded together to form a prelaminate unit. The prelaminate unit is then degassed under vacuum heating as described herein, and the remaining rim is electron beam welded to hermetically seal the prelaminate unit to core 1 and thus a shell 6 to form core 1. Thus, the end edge must be welded in a vacuum to remove the gases from the interior of the prelaminate unit. Then, the prelaminate unit is ready to be hot isostatically pressed into the laminate 5 or 69 according to the principles of this invention after passing the leakage controls, as set forth herein.

A number of laminates have been prepared and tested. The following examples indicate the materials and procedures used.

Example I.

A laminated article was produced according to the principles of this invention using a 0.75 mm thick core of TZM, a molybdenum based alloy and 2.38 mm thick platinum based alloy plates. In particular, the casing plates 30 consisted of a J alloy containing an approximately 75% / 25% platinum alloy, respectively. rhodium, as is known in the art. TZM is a commercially available alloy with about 0.5% titanium, 0.08% zirconium, 0.015% carbon and the remainder molybdenum.

The plates and the frame were formed into a shell for receiving the core material by welding along the edges of the plates and the frame, leaving an edge open for insertion of the core material into the cavity formed therein. The sheath was shaped to fit snugly on the outside of the core material.

After molding the core and the casing materials to the desired shapes, the J alloy casing materials were immersed in king water 5 at 350 ° F (177 ° C) for 20 minutes to clean the surface thereof. Also, the TZM core was immersed in the above acid bath for six minutes at room temperature.

After the cleaning steps, both the J 10 alloy shell and the TZM core were rinsed in water and then alcohol and air dried. After drying, the shell was applied to the core to form a prelaminate unit. The prelaminate unit was then designed for the superheat and vacuum degassing treatment. Thus, with an edge of the casing left open, the prelaminate unit was placed in an autoclave and heated to 2000 ° F (1093 ° C) at a vacuum of 1.8 x 10 µ torr for at least an hour for further cleaning.

Following the degassing treatment under heating and vacuum, the prelaminate unit was placed in a vacuum chamber and the remaining rim was welded to completely enclose or hermetically enclose the core within the envelope. Welding must be done in a vacuum to remove the gas from the cavity of the casing for proper connection. As such, electron beam welding of the end edge is preferably used, since electron beam welding is normally performed in a vacuum chamber. However, an evacuated chamber using laser welding can be acceptable.

Following the core sealing within the shell, the prelaminate unit should be checked for porosity. This was done by subjecting the sealed prelaminate unit to gaseous helium at a pressure of 250 psi (1.72 x 10 N / m) for 1 to 2 hours.

When removed from the pressurized environment, the sealed prelaminate unit was immersed in alcohol to look for bubbles, which would indicate the presence of a hole or porous section.

After passing the leakage control test, the prelaminate unit was hot isostatically pressed at a temperature of about 2400 ° F (1316 ° C) at about 15000 psi (1.03 x 10 ° N / m2) for about 1 hours to produce a laminate according to the principles of this invention. Such a laminate exhibits the ability to operate at temperatures and stresses much higher than a similar article made only from the TZM or platinum alloy or laminates thereof made by other processes.

Example II.

Another laminate was prepared as in Example I, except that another platinum-based alloy known as H-alloy was used for the shell material. H alloy is an alloy consisting of about 90% platinum and about 10% rhodium as is known in the art. Since the materials have different properties, the parameters of hot isostatic pressing of the core and the shell were different from those in Example I.

With the H alloy and the TZM laminate, it is preferred that the article be subjected to the HIP treatment at about 2300 ° F (1260 ° C) at about 15000 psi (1.03 x 10 ^ 2 N / m) for about 2 o'clock. When using these materials and processes, the laminated article also exhibits better properties than the individual materials and / or other laminates of the same materials formed by other processes.

Example III.

Using steps similar to the previous examples, a laminated article was produced with a TZM core and a casing of at least substantially pure or unalloyed platinum. The casing material in this case was 9.9.9 +% pure platinum. Again the parameters for the HIP treatment were changed to adapt to the differences in casing material. As such, to optimize the HIP procedure for a pure platinum shell over a TZM core, the article was subjected to the HIP treatment at a temperature of 2200 ° F (1204 ° C). at 1250 psi (8.6 x 10 ^ N / m2) for 3 hours. Again, the laminated article showed better properties than the 8120396-14 individual elements and / or laminates produced by other processes.

Example IV.

Another laminate was prepared as in the previous examples using a niobium based alloy known as Fansteel 85 (FS85) coated with at least substantially pure or unalloyed platinum. Fansteel 85 is a niobium-based alloy with approximately 60.65% niobium, 27.5% tantalum, 11.0% tungsten, and 0.85% zirconium.

After similar surface preparation procedures, the niobium alloy was immersed in an acid bath, which, by volume, consists of 1.5 parts of 48% hydrofluoric acid, 2 parts of 70% nitric acid, 1 part of 95% sulfuric acid, and 5.5 parts distilled water. The platinum was immersed in king water to clean its surface. Both the core and the casing were then rinsed in water and then in alcohol and then air dried.

The unalloyed platinum was hot isostatically pressed onto the niobium-based alloy at 2400 ° F (1316 ° C) at 15000 psi (1.03 x 10® N / m2) for about 3 hours. Therefore, a good metallurgical bond was obtained between the core and the shell.

As with the other laminate of the other examples, the previous laminate was placed in contact with molten glass at about 2400 ° F (1316 ° C) with some of the laminate extending into the atmosphere. Again the laminate showed better strength and oxidation resistance.

Example V.

Another laminate or article was similarly prepared using at least substantially pure or unalloyed tungsten which was intimately bonded to a platinum-based alloy. The platinum-based alloy, otherwise known as J alloy, consists of about 75% platinum and about 25% rhodium. The precious metal alloy was immersed in king water, rinsed in water, and then rinsed in alcohol to prepare the surface lacquer eryan.

The tungsten core was immersed in an acid solution consisting of, by volume, 3 parts of 70% nitric acid, 1 part 48% hydrofluoric acid and 4 parts distilled water for a period sufficient to clean the surface of the core. The core was then rinsed in water and then in alcohol.

After assembly and degassing, the pre-10 laminate unit was hot isostatically pressed as set forth herein. The article was then placed in contact with molten glass at 2400 ° F (13.16 ° 1) for a period of time to determine that such a laminate can provide better strength and corrosion resistance.

As with the other examples, a good metallurgical or fusion bond was formed between the tungsten and the platinum alloy.

When the articles produced according to this invention are used in high temperature environments, the heat stresses occurring in the laminate due to the difference of expansion coefficients between the core and the casing must be taken into account. Thus, the precious metal-formed layer bonded to the flame-resistant metal substrate must be compatible with it in terms of heat stress considerations.

It is desirable that the stress factor (oh E) of the expansion coefficient (oo) in microinches per inch ° F and the modulus of elasticity (E). in million psi is as close as possible to the stress factor (JjE) of the expansion coefficient (ς / ί]. and the modulus of elasticity (E) of the precious metal layer or shell.

For an acceptable laminate, the heat stress ratio (R) of the stress factor of the yuuryaste metal (0 ^ rm Erm) divided by the stress factor 35 of the precious metal layer {</ rpm Epm) should be in the range of about 0.4 to about 1.6. And if the ratio is in the range from about 0.6 to about 1.4, the metals are more compatible. Preferably, however, the ratio should be in the range of about 40 Qf7 to about 1.3 for excellent results. Therefore: 8120306 -16- t /, rm Erm R = '..........

t / j pm Epm 0.4 <R 5 1.6 acceptable 0.6 R <1.4 more compatible 5 0.7 i R f 1.3 excellent

If the stress factors for the precious metal and the refractory metal differ too much, the laminate may tend to break or delaminate due to the thermal stresses generated therein when the laminate is placed in a high temperature environment. The following tables of the thermal stress ratios (R) show that some combinations provide a laminate with greater compatibility than others.

thermal stress ratios (R)

15 TABLE I

Pt Rh H alloy J alloy Pd

Ti 0.75 0.40 0.50 0.56 0.74

Zr 0.41 0.22 0.28 0.31 0.41

Hf 0.63 0.33 0.42 0.47 0.61 20 V 0.84 0.45 0.56 0.63 0.82

Cb 0.52 0.28 0.35 0.39 0.52

Ta 0.93 0.50 0.62 0.70 0.91

Cr 1.17 0.63 0.78 0.88 1.15

Mo 1.22 0.65 0.81 0.91 1.19 25 W 1.22 0.65 0.81 0.91 1.20

Mn 2.69 1.44 1.79 2.01 2.64

Tc 1.75 0.94 1.16 1.31 1.72

Re 2.36 1.26 1.57 1.77 2.32 TZM 1.26 0.68 0.84 0.95 1.24 30 FS85 0.72 0.38 0.48 0.54 0.70 81 2 0 3! **.

-17- TABLE II.

Os Ir Ru Au Ag

Ti 0.37 0.27 0.26 0.86 0.66

Zr 0.21 0.15 0.14 0.48 0.37 5 Hf 0.31 0.23 0.21 0.71 0.55 V 0.42 0.30 0.29 0.95 0.73

Cb 0.26 0.19 0.18 0.60 0.46

Ta 0.46 0.34 0.32 1.06 0.82

Cr 0.58 0.43 0.40 1.34 1.03 10 Mo 0.60 0.44 0.41 1.29 1.07 W 0.61 0.44 0.42 1.39 1.07

Mn 1.33 0.98 0.92 3.06 2.36

Tc 0.87 0.64 0.60 2.00 1.54

Re 1.18 0.86 0.81 2.69 2.07 15 TZM 0.63 0.46 0.43 1.44 1.11 FS85 0.36 0.26 0.25 0.82 0.63

Laminates with thermal stress ratios outside the widest range specified herein are not recommended for extremely high temperature applications. However, it will be understood that such laminates may be suitable for applications where extremely high temperatures do not occur. Since the thermal stress generated is also a function of the temperature experienced by the laminate, this voltage can be within acceptable limits even if the stress ratio is outside this range because the temperature experienced is sufficiently low.

Furthermore, the laminate must also be designed so that the melting point of the refractory metal core and the melting point of the precious metal shell must be higher than the operating temperature experienced in operation. For example, in the production of glass fibers, the molten glass can be at a temperature of about 2100 ° F (I149 ° C); the fiber molding feeder may have an operating temperature generally equal to the temperature of the molten glass. In general, these fiber mold feeders are within about 100 ° F (about 50 ° C) of this molten glass.

Generally, in the laminates produced in accordance with this invention, a zone of intermetallic compounds will exist due to the core and the casing in each other. As such, the intermetallic compounds of this zone will exist as a full spectrum for the zone. In some instances, the melting points of these compounds can vary greatly from the core material or the casing material or both. To be very useful, the melting point of the lowest melting compound in the interdiffusion zone must also be greater than the operating temperature that occurs. The melting points for these compounds can in some cases be found in the binary phase 15 diagrams developed for some of the refractory and precious metal alloys.

The following tables list the different liquidus temperatures of the spectrum of compounds formed between the specified refractory and noble metals.

TABLE III.

Liquidus temperatures of the lowest melting compounds of refractory and precious metals, x)

Ti Zr Hf _V_ N Ta 25 (3035) (3366) (4032) (3450) (4474) (5425) <1668) <1852) <2222) <1899> <2468) <2996>

Ru (4530) 2867 2264 3110 3254 3231 3583 <2499> <1575> <1240> <171θ) <1790> (llll) <1973/30 Os (4900) 2732 2300 - 4064 3848 4300 <2704) <1500> <ί 260> <224θ) <^ 12Q> <237l)

Rh (3571) 2336 1949 - 2768 2736 3169 35 <1966) <1280) <1065) <ΐ52θ) <1502) (174¾)

Ir (4449) 2687 2237 2687 3362 3348 4188 ^ 2454) <1475) {1225) <Jl475) <ΐ85θ) <1842) ^ 309 ^) 8120396 ^ t -19-

Ti Zr Hf VN Ta

Pd (2829) 2068 1886 2444 2844 3092 (l554 / (ll42) <^ 030) (ΐ34θ) (l562) (ΐ70θ) 5 Pt (3217) 2412 2100 3128 3100 3100 3200 (l769) (1322) (1149) (ΐ72θ ) (l704 / ¢ .760)

Ag (1761) 1888 2079 10 ¢ 61) (l0 3l) ¢ 137)

Au (1945) 2053 1949 2552 2858 (l063) ¢ 123) (l065) ¢ .400) ¢ .570) TABLE IV.

15 Cr Mo W Tc Re (3407) (4730) (6170) (3870) (5755) {1875) (26ÏO) (3410) (2132) (3179 /

Ru (4530) 2930 3538 4008 - 4530 20 (2499) ¢ 610) (l9A8) (2209) - (2499)

Os (4900) 3344 4900 4946 - 4900 (2704) (ΐ84θ) (2704) (2730) ¢ 704 /

Rh 25 (3571) 2687 3524 3819 3632 4766 (1966) ¢ 475) (1940) ^ 104) (2OO0) <26 30 ^

Tr (4449) 3056 3781 4180 4172 5081 (2454) (l 6 8 q) (2083 / (2309) (2300) (2 8 0 5> 30 Pd (2829) 2399 3168 3299 2912 3002 (1554) (1315) ¢ 742 / <1815) (l600) (ΐ65θ)

Pt (3217) 2732 3781 4467 1596 4442 35 (l769) (1500) (2083) (2464) (869) (2450 ^ 8120396 -20-

Cr Mo W Tc Re

Ag - - - - - (1761) 26 33 661 / <1445 ^

Au 5 (1945) 2120 - 1760 (1063) (ΐΐ6θ) (96θ) x) The numbers in brackets indicate the melting points of the pure metals. All temperatures are listed in degrees F first, and the corresponding temperatures in degrees C10 are listed as ^ ---- ^.

While some systems can be used where the operating temperature is greater than the recrystallization temperature of the core or substrate, it is also preferred that the recrystallization temperature of the core be greater than the operating temperature. In most cases, when the material experiences a temperature greater than the recrystallization temperature, the material crystallizes and loses strength.

Such laminates can be used at temperatures greater than their recrystallization temperature. In this case, the core will generally lose some of its strength, but this can be contrasted by changing the geometrical boundaries of the core to change the moment of resistance. For example, increasing the thickness of the core board by about 20% must compensate for core material, which loses about 35% of its strength.

With laminated articles produced in accordance with the principles of this invention, these articles are quite easily able to withstand temperatures up to 2400 ° F or 2800 ° F (1316 ° C or 1538 ° C) or more. In some instances, laminates can be designed to withstand temperatures above 3500 ° F (1927 ° C), 4000 ° F (2204 ° C) or more. For example, the melting point of rhenium (Re) is a flame resistant metal, set at 5755 ° F + 35 ° (3179 ° C + 18 ° C). The melting point of osmium (Os), a precious metal, is set at 4900 ° F + 350 ° (2704 ° C + 175 ° C). Since rhenium and osmium form a solid solution, the melting point 8120396 * -21- of the lowest melting compound formed between osmium and rhenium will be osmium, which is 4900 ° F + 350 ° (2704 ° C + 175 ° C). Also, the thermal stress ratio of the Re / Os laminate is equal to about 1.18. Therefore, a laminate useful for exceptionally high temperature can be formed therefrom.

Likewise, a tungsten (W) core coated with osmium (Os) should yield an intermetallic compound with a melting point of about 4946 ° F (2730 ° C), the lowest formed by the series of tungsten and osmium compounds. Its thermal stress ratio is about 0.61. Thus, another high temperature resistant laminate, which is useful at extremely high temperature, can be formed therefrom.

Iridium (Ir) has a melting temperature of 154449 ° F + 5 ° (2454 ° C + 3 ° C). The melting temperature of the lowest melting compounds of the spectrum of compounds formed between a laminate of rhenium (Re) and iridium is about 5081 ° F (2805 ° C). Since the lowest melting point of the three respective melting points, that of unalloyed iridium, is 20 at 4449 ° F + 5 ° (2454 ° C + 3 ° C), the operating temperature must be lower than the melting point of the unalloyed iridium. Furthermore, the voltage ratio of rhenium to iridium is about 0.86. Thus, the laminate must provide good high temperature utility. A fiber cap feeder with blind caps 25 using a laminate produced according to the parameters listed in Example I was heated to 2300 ° F (1204 ° C) in an oxidizing atmosphere in contact with molten glass. Even after a period of more than 380 days at such a temperature, there was no external evidence of core oxidation or delamination between the core and sheath material. Articles produced according to the principles of this invention are well suited for use in high temperature oxidizing environments. As such, they are especially suitable for use in contact with molten glass. In particular, such laminated articles are suitable for fabricating elements used in glass fiber forming feeders and spinning members or rotors? flow channels, electrodes, and agitators for lasers and forehearths, and for pump manufacture to pressurize molten clases. For example, the 8120396 -22- * rotor and stator of a progressive cavity pump can be fabricated from a laminate produced in accordance with the principles of this invention.

When a laminate is used in place of a conventional single platinum alloy layer resistive heating fiber mold wall, the power supply and control system must be adjusted to compensate for differences in thermal and electrical resistance between the conventional wall and a laminated wall, if present .

As shown in Fig. 4, a feed member 10 consisting of containment or side walls 12 and a bottom processing or flow-forming wall 14 is arranged around a plurality of flows of molten inorganic material, such as glass, to deliver. The molten glass streams can be drawn into fibers 16 by the operation of a winding machine 26.

As is known in the art, a binder applicator 18 is applied to apply a coating or binder 20 to the surface of the glass fiber, which advances towards the collection shoe or agent 20 to be collected into a strand or bundle 22. The strand 22 is then wound into a package 24 on a winding spindle of the winding machine 26. FIG. 4 thus schematically shows a "tex-25 tile!" fiber forming system.

As shown in Fig. 5, a rotating system 40 consists of a flow means or channel 42 with a mass of molten inorganic material 44, such as glass therein. A stream of molten glass 46 is supplied to a channel 42 rotary feeder or rotor 50 as is known in the art. The rotor 50, which is capable of being rotated at high speeds, consists of a hollow shaft 42 and a flow-forming or processing peripheral wall 54 with a number of openings 71, holes 77 or channels 88 therein which are suitable for feeding a number of streams of molten inorganic material to be formed into fibers,

In conjunction with the rotor 50, a cap 56 and a circumferential blower or fluid extractor 57 40 are provided to assist fluid retraction of the molten material straws to fibers or filaments 60. A binder or cover can be applied to the fibers 60 by means of binder applicators 58, as is known in the art.

As shown in the drawings, the fiber shape or processing walls 14 and 54 of the feeders 10 and 50 must be based on laminate, consisting of a refractory metal core, which is provided with an oxygen impermeable, noble metal existing casing intimately connected thereto by hot isostatic pressing (ie HIP) as described herein.

In particular, these refractory metals are selected from the group of materials consisting of molybdenum (Mo), tungsten (W), rhenium (Re), tantalum (Ta), 15 hafnium (Hf), titanium (Ti)., Chromium ( Cr), zirconium (Zr), vanadium (V). and base alloys of these refractory metals. For example, an alloy of molybdenum, titanium, and zirconium known as TZM has been found to provide better laminated wall for a fiber molding feeder when coated with a precious metal alloy of platinum and rhodium.

In particular, the precious metals are selected from a group consisting of platinum (Pt), paladium (Pd), irridium (Ir), osmium (Os), rhodium (Rh), ruthenium (Ru), and alloys, which are based on such metals. Platinum alloys include H alloy and J alloy, which are platinum and rhodium alloys with the composition 90% / 10%, respectively. 75% / 25%.

As described herein, care must be taken in preparing the surfaces of the substrate and the precious metal layers to ensure a good bond between the core and the shell.

Simply put, the casing is shaped to precisely match the outside of the core with its surfaces cleaned appropriately to promote a good metallurgical bond therebetween. The core is inserted into or confined within the envelope to form a prelaminate unit, at least one edge or portion of which is open to atmosphere to facilitate "degassing-8120396 * 24-sing". Then the prelaminate unit is heated in a vacuum to "degass" the unit. Following the degassing, the open edge or seams of the unit are welded or closed in vacuum, after which the unit is ready to be hot isostatically pressed to form the laminate 69.

As shown in Fig. 6, the laminate 69 is formed by hot isostatically pressing core or substrate 70 onto the envelope 72 to form the laminate 69. At this point, the envelope 72 should completely surround the outside of the core 70.

A number of openings 71 extending through the laminate 69 or 5 are formed by a suitable means such as by drilling. Preferably, the openings 71 are formed in the core 70 and the shell 72 after the HIP operation or procedure for forming the laminate 69.

The opening 71 as such exposes a portion of the refractory metal core 70 which may be exposed to an oxidizing atmosphere during operation. However, the laminate with the opening 71 therein can still function if molten glass is continuously maintained in the opening over the refractory core to prevent the oxygen-containing atmosphere from contacting the core. However, this is not always practically feasible in factory operation. Therefore, the opening 71 of the laminate 79 must be provided with a precious metal cover or liner 74 which is bonded to the casing 72 and / or the core 70 to prevent oxidation of the core material.

An insert or element 74 preferably consists of the same type of precious metal shaped material as the casing 72. However, different but compatible materials can be used.

Essentially, the element 74 is inserted into the laminate 79, whereupon a first flange or head 78 and a second flange or head 79 are formed therein to abut the outer surfaces of the casing 72. Thus, a portion of the casing 72 becomes placed between core 70 and each flange 78 and 79.

The insert 74 may consist of a solid 8120396 -25 plug or, preferably, a wool eyelet or element with an opening 77 extending therethrough. The opening 77 is formed by a sleeve 76 placed between and adjacent to the flanges 78 and 79.

Preferably, the element 74 is formed as a hollow precious metal-shaped eyelet, which has a flange such as the flange 78, which is preformed therein. The eyelet 74 is then inserted into the opening 71 and the other flange is formed therein, so that the flanges 78 and 79 abut against the casing 72.

At this point, the element 74 may be welded or joined to the laminate 69. In one method, the flanges 78 and 79 are electron beam or laser welded to the portion of the Qrohilsel 72 bonded therewith to the core 70 to be closed off from the environment or atmosphere around the bottom wall 14.

Preferably, the element 74 is hot isostatic pressed or gas pressure welded to the laminate 69 so that the sleeve 76 is intimately joined to the envelope 72 and the core 70 so that the flanges 78 and 79 are intimately connected to the envelope 72 Good electrical and thermal conductivity are thus obtained by the connection of the element 74 and the laminate 69.

According to the HIP welding technique set forth in the Metals and Ceremics Information Center Report No. 25. MCIC-77-34 published by the Battelle Columbus Laboratories in November 1977, the hollow members 74 can be attached to the laminate 69 by the HIP welding technique.

When the elements 74 are slid into the laminate 69 as in Fig. 6, the laminate 69 is placed in a sheet metal container with a pressure transmitting medium tightly packed between the container and the laminate 69 and in the opening 77 of each element 74. Thus, the pressure transmitting medium is tightly packed in the entire space within the container which is not occupied by the laminate 69 and the elements 74.

The pressure transmitting medium may be of the type known in the art, such as powdered metal, pearl or granular glass, such as "Vycor", or amorphous silicate. Preferably, openings 77 are made 8120396-26- by pressing with a solid or fully compacted rod the pressure transmitting medium, metal or silica, which becomes liquid or soft upon application of heat and pressure during the HIP process as well as the rest of the pressure transmitting medium to ensure complete application of pressure to the walls of the sleeve 76 to intimately connect the outside of the sleeve 76 to the core 70 and / or the casing 72 at the opening 77.

Preferably, the pressure-transmitting medium should not become so fluid that it seeps between the surfaces to be joined together.

The pressure transmitting medium is then removed by any suitable means, such as leaching.

It should be noted, however, that the elements 74 and / or parts 84 can be attached to the laminate 69 and / or to each other in the argon fluid of a conventional HIP system by the HIP welding technique if the flanges 78, 79 and 87 are hermetically sealed or welded (eg EB welded) on the laminate 69. The sheet metal case and the special pressure-transmitting medium are then not necessary.

Thus, in the HIP welding technique, the flanges 78 and 79 are metallurgically bonded to the shell 72 and the sleeve 76 is metallurgically bonded to the laminate 69 to provide a laminated fiber mold wall 14.

The openings 77 may be sized to provide the proper passage for flowing molten glass or inorganic material therethrough in a stationary or rotating fibrous system, i.e. for textile or wool operation.

In some instances, it may be desirable to attach a precious metal shaped tubular molding 84 to the laminate 69 and / or one of the flanges 78 or 79 or the inner wall of the opening 77. Preferably, the part 84 consists of the same material as the element 79 and the casing 72.

As shown in Fig. 6, the tubular member 84 consists of a hollow precious metal shaped shaft 86 with a flange 87 at one end thereof. Passageway 88 extends through shaft 86 and flange 40 87 and is capable of flowing molten glass and / or inorganic material therethrough.

With reference to attaching the part 84 to the laminate 69, in addition to directly attaching the tubular part 84 to the casing 72, it is also meant that any part of the part 84 may be attached to the element 74, which is connected to the laminate 69.

In one method, the flange 87 of the part 84 can be welded to the flange 79 with an electron beam or laser to permanently secure the tubular part 84 to the laminate 69.

Preferably, the tubular member 84 is attached to the member 74 and / or the laminate 69 by the HIP welding technique in accordance with the method set forth above to obtain good electrical and thermal contact from the member 84 to the laminate 69. Thus, the passage 38 should preferably be filled with a solid rod of a suitable pressure transmitting agent; of course, the opening 77 is occupied only by the part 84. Instead of two separate HIP operations to connect a first element 74 to the laminate 69 and a second HIP operation to connect the part 84 to the element 74 and thus the laminate 69, a hollow member 74 may be retracted and flanged by cold deformation 25 and then the tubular member 84 slid therein, after which the hollow member 74 and the tubular member 84 are joined together and at least with the laminate 69 can be connected almost simultaneously through a single HIP operation.

The processing wall 14 can be combined with side walls 12 to form a textile-type feeder 10 with a capless bottom wall. However, a hollow tubular member or cap 84 can be attached to the laminate 69 to form a capped processing wall 14, as shown in Fig. 6. Preferably, the hollow tubular member 84 is also formed from any of the above noble metals or base alloys thereof, such as platinum.

Since refractory metals are highly creep resistant 40, or are at least virtually creep resistant, even at high 8 1? At temperatures of 28, fiber forming feeders produced according to the principles of this invention have good sag resistance. The fiber-molded walls will thus not deform or bend as strongly as a feeder consisting entirely of precious metal. In some cases, sagging can be at least substantially avoided over the life of the feeder. Thus, fin shield arrangements and the like with respect to the fiber mold wall and / or caps can remain essentially fixed over the life of the feeder.

The laminate 69 can be fabricated as a substantially flat wall to form a fiber mold wall 14, generally for a textile type feeder, or the laminate 69 can be fabricated into a cylindrical fiber mold wall 54 with openings 77 and / or a passage 88 extending radially outward from its axis of rotation, generally for wool operations.

In any case, the openings 77 or passages 88 must be of the correct size to allow the molten glass or inorganic material to flow through them in a stationary or rotatable fiber molding system.

For a rotatable fiber-forming system 40, the fiber-forming circumferential wall 54 may be substantially similar to the system depicted in Figs. 6, 25 except that a circumferential wall 54 must be formed as a hoop instead of an at least substantially flat bottom wall 14.

As such, the processing wall 54 may be configured to allow the molten glass to flow directly through the openings 71, i.e. without a tubular member 84 slid into the openings 71. However, tubular members 84 may be provided as explained above.

As shown in Fig. 7, the bottom wall 14 consists of a laminate 69 or 50 suitable for flowing molten glass therethrough. As such, the core or substrate 170 is provided with a number of openings 172 by an appropriate means such as drilling.

An insert or element 174 is placed 40 or pressed into each of the openings 172 in the core 170. To ensure an accurate fit between the element 174 and the core 170, a press fit is preferred. The flat end faces 173 and 175 of the element 174 should be substantially smooth or in the same plane with the flat faces of the core 170. Thus, preferably, the plugs are formed with an axial height substantially equal to the thickness of the cores 170. Each element may be a cylindrical precious metal solid plug suitable to fit precisely within each opening 172. If the plug is longer than the thickness of the core 170, preferably the protruding out of the opening 172 excess of the insert removed.

Following deployment of the elements 174, a sheath 176 is fabricated or formed around the core 170. The sheath 170 must be formed of a precious metal as described herein.

As shown in the drawings, the substantially parallel end faces .173 and 175 of each element or plug .174 are intimately connected to the inner faces 177 and 179 of the shell 176 after the HIP operation. Each of the end faces of each plug is substantially in the same plane as the associated side of the casing 176.

At least one opening 178 is formed in the element 174 to form the processing wall 14, preferably without exposing the refractory metal core 170.

The processing wall 14 can be combined with the side walls 12 to form a textile type feeder 10 with a capless bottom wall. However, a hollow tubular member or cap 180 may be attached to the laminate 69 to form a cap-type processing wall 14, as shown in Figs. 8 and 9. The hollow tubular member 180 and member 174 are also preferably formed from any of the aforementioned precious metals or base alloys thereof, such as platinum.

As shown in Fig. 8, the shaft 182 of the hollow tubular member 180 is placed in the opening 178 of the laminate 69. Furthermore, the flange 40 184 of the member 180 is placed in abutting contact 8120396-30 with one side of the sheath 176 and then connected to the sheath 176 by an appropriate means, such as electron beam or laser welding.

The portion of the shaft 182 protruding beyond the opposite surface 5 of the casing 76 forms the "cap" and the passage 183 through the part 180 is adapted to allow the passage of molten glass or inorganic material therethrough to flow therefrom. feed.

Preferably, instead of welding the flange 184 to the sheath 176 with an electron beam 10 or laser, the gas pressure hollow tubular member 180 or the HIP treatment may be welded to the laminate 69 as set forth herein.

Thus, in HIP welding, the flange 184 is metallurgically connected to the casing 176 and the shaft 182 is metallurgically connected to the element 174 to form a laminated feeder fiber mold wall 14, in which the tubular member 180 makes good electrical and thermal contact with the laminate 69.

As shown in Fig. 9, a modified laminate 69 having a core 170, an element 174, and a sheath 176 fabricated as set forth herein includes a hollow tubular member 180 projecting on one side of the core. sheath -176. Preferably, the member 180 is mounted on the non-glass-contacting side of the fiber-forming feeder.

As such, the flange 184 can be welded to the casing 176 by any means such as resistance welding, electron beam welding, laser welding or HIP welding.

Likewise, a rotary feeder 50 can be fabricated from a laminate 69 consisting of a refractory metal-formed core or substrate 190 intimately bonded to a precious metal shell 196 by hot isostatic pressing. The fabrication steps for the rotary feeder wall, as shown in Fig. 10, are substantially the same as the foregoing described for the feeder 10, wherein an opening 192 is first formed in the substrate 190 and the element or insert 194 is inserted therein. pressed or fitted tightly.

8120396 -31-

Thereafter, an envelope is formed around the core 190 with the element 194 slid therein. After the HIP treatment, an opening '19 8 can be formed in the element 19 4 to allow the molten glass to pass through it. Preferably, there should be no points where the core is exposed to an oxidizing medium or atmosphere. The opening .19 8 must therefore be drilled entirely within the circumferential wall of the element 194.

It will be appreciated that the inserts elements 174 and 194 need not be solid plugs of precious metal material, but the elements 174 and 194 before they are deployed in core 170 and core 190 passages 183 and 198 which have been previously formed therein. Furthermore, the fiber-forming wall 94 can, if desired, be provided with elements 184 and / or 194.

As shown in Fig. 11, the tubular member 184 consists of a sleeve 185 with a projection 286 projecting beyond the first flange 288. Thus, the first flange 288 is between the two ends 293 and 294 of the sleeve 285.

The sleeve 185 forms a channel 291, which is or is made to flow molten glass therethrough.

The tubular member 284 may have a channel 257 which extends from one end to the other or the second end 294 may be closed, as shown in Fig. 11. As such, after the tubular member 284 is slid into the laminate 269, according to the principles of this invention, the second end 294 will then be opened mechanically to expose the channel 291 to the second end 294.

Preferably, the tubular hollow element 284 is made of precious metal, and preferably it is substantially the same as the precious metal shell material, although other but compatible materials may be used.

As shown in Fig. 12, the laminate 69 is formed from a core or substrate 270 and a precious metal shell 272 hot isostatically pressed 40 to intimately bond the shell 272 to the core 270. The 8120396 -32-4 Casing 272 consists at least in part of a first plate 280 and a second plate 281 intimately connected to core 270.

A plurality of openings 271 are formed in the laminate 69 to provide a fiber forming feeder capable of supplying numerous molten glass streams to be drawn into fibers. However, only one such opening 271 and a fragment of the laminate 69 are shown in Figures 12 and 13.

Preferably, the opening 271 is formed in the laminate 69 following the HIP process to form the laminate 69. However, it will be appreciated that the opening 271 extending through the core 270 and the sheath 272 may be obtained by providing a core and sheath with mating holes 15 which can be aligned to form the openings 271. to gain.

In practice, the tubular member 284 is slid into the opening 271 so that the first flange 288 is brought into contact or abutting contact with the first plate 28Q of the casing 272. Part of the sleeve 285 or its first end 293 protrudes beyond the outer surface of the second plate 281 by a sufficient distance to allow the second flange 289 to be formed therefrom. The flange 289 is formed so that it is in firm contact with the outer surface of the second plate 281.

In order to protect the core 270 from high temperature oxidation, the tubular member 284 must be joined to the laminate 69. In one method, the first and second flanges 288 and 289 are welded to the first and second plates 280 and 281, respectively, by a suitable welding technique, such as welding with an electron beam or laser. Preferably, this welding should be in a vacuum to remove the gas between the wall of the opening 271 and the tubular member 284.

Preferably, the Tubular part 284 should be welded or gas pressurized to bond the tubular part 284 to the laminate 69 .. With the correct HIP welding operation, the sleeve 285 is intimately bonded to the core 270 and the sheath 272 and 40, the first and second flanges 288 and 269 are intimately joined 8120396 -33- to the first and second plate 280, respectively. 281.

The hollow tubular member 280 can be gas pressure welded or HIP technique welded to the laminate 69 as set forth herein. Thus, in HIP 5 welding, the flanges 288 and 289 are metallurgically bonded to the sheath 272 and the sheath 285 is metallurgically bonded to the core 270 and the sheath 272 to provide a laminated feeder fiber mold wall 14 in which the tubular member 284 is in good electrical and thermal contact with the laminate 69.

As shown in Fig. 13, the protrusion 286 extends outwardly from a first plate 280 and generally into the fiber-forming zone. Although the second plate 281 of the casing 272 would normally be placed in contact with a molten glass or inorganic material. Thus, a "cap type" fiber mold wall is produced from a laminate 69 and a unit member 284.

As shown in Fig. 14, the laminate 69 is formed by hot isostatically pressing a core or substrate 370 onto a sheath 372 and element 374. The sheath 372 and element 374 must completely cover all outer surfaces of the core 370 to prevent the oxidation of the core during fiber formation.

A plurality of openings 371 or at least one opening 371 extending through the core 370 is formed by any suitable process such as by drilling. Then, the hollow tubular member 374 is slid or placed in each of the openings 371. The element 374 may initially be supplied as a solid rod, hollow tubular sleeve or hollow eyelet with a preformed first flange or head 378 along the length of it. Preferably, the flange 378 is located at one end of the sleeve 376 of the element 374.

If the element 374 includes a preformed first flange 378, the element 374 is cold formed or spread to obtain a second flange 379 at its opposite end to form a precious metal liner or tubing for the opening 371 in core 370. As such, flanges 378 and 379 preferably lie in firm abutting contact with the outer surfaces 40 of core 370, 8120396 -34-

Following retraction and flanging of the element 374, a precious metal shell 372 is formed around the core 370.

In one method, a window or frame of precious metal strips is placed in abutting contact with the side edges of the plate core 370. The core 370 with inserts 374 therein and the window frame of precious metal material are interposed between a first plate 373 and a second plate 375. The plates 373 and 375 10 preferably consist of the same precious metal as the window frame and inserts 374.

Of course, the core 370, the shell 372 and the element 374 must be suitably prepared for isostatic pressing, as set forth herein. Preferably, the plates 373 and 375 have no holes extending therethrough prior to laminating.

After the HIP treatment, the core 370 and the shell 372 form a laminate 69 with a precious metal element, which are intimately joined together. The element 374 has a first flange 378 at one end and a second flange 379 at its opposite end, the flanges 378 and 379 being between the core 370 and the shell 372.

The tubular member 384 may have a channel 388 formed therein prior to insertion of the tubular member 384 into the opening 377 of the member 374.

If the element 374 is supplied as a hollow element with a sleeve 376 interposed between a first and second flange 378 and 379 with an opening 377 extending therethrough and the plates 373 and 375 may be substantially without holes, the openings 377 are easily placed, as recessed dimples will generally be formed in the plates 373 and 375 at each associated opening 377 as a result of the HIP treatment.

As such, a passage 381, as an extension of the opening 377, may be formed by the plates 373 and 375 in communication with the opening 377 to allow the molten material to flow therethrough. Thus, a "capless" fiber-forming feeder can be fabricated.

A "capless" fiber forming feeder can be fabricated 8120396-35- as shown in Fig. 15 by sliding the tubular member 384 into the opening 377 so that the shaft 386 projects at least partially therethrough and so that the flange 387 formed at an end 5 of the shaft 386 of the tubular member 384 in abutting contact with the sheath 372. Then, the tubular member 384 with the passage 388 therethrough is to be connected to the sheath 372 and / or the member 374.

The flange 387 of the tubular member 384 must be connected to the shell 372 by welding, such as electron beam or laser welding. Preferably, the tubular member 384 is hot isostatically pressed onto the laminate 69, so that the flange 387 and the shaft 386 with the tubular member 384 are intimately connected to the element 374 and the shaft 372 to provide electrical and thermal conductivity and in addition obtain additional protection for the core 370 against oxidation.

The hollow tubular member and / or inserts can be gas pressure welded or HIP technique welded to laminate 69 as set forth herein.

With the inserts and / or the tubular member retracted into the laminate 69, the laminate 69 and all such inserts and / or components are placed within a sheet metal container with a pressure transmitting medium tightly packed between the container and the laminate 69 and in the openings and / or passages of each insert and / or tubular member. Thus, the pressure transmitting medium is tightly packed in the entire space within the container, which is not occupied by the laminate 69 and the inserts and the tubular parts.

It is noted that the element and / or parts can be welded to the laminate and / or to each other with the HIP treatment if the flanges are hermetically joined or welded (eg EB welded) to the laminate 69, in the argon fluid of a conventional HIP treatment system, The sheet metal case and the special pressure transmitting medium are no longer necessary.

40. With the HIP welding method, the flange 387 8120396 τ ψ -36- is metallurgically bonded to the sheath 372 and the shaft 386 is metallurgically bonded to the member 374 to provide a laminated feeder fiber mold wall -14 in which the tubular member 384 is in good condition. electrical and thermal contact with the laminate 69. Preferably, the element and / or part are made of the same type of precious metal material as the case, although different but compatible materials can be used.

The laminate 69 may be fabricated as a substantially flat wall to obtain a fiber-molded wall 14 generally for a textile type feeder, or the laminate 69 may be fabricated into a cylindrical fiber-forming wall 54 having openings and / or channels. extending radially outward from its axis of rotation generally for wool operations.

In any case, these openings and / or channels must be the correct size to allow the molten glass or inorganic material to flow through them in a stationary or rotating fiber molding system.

It will be apparent that within the scope of the invention, modifications and other embodiments other than described herein may be made. The present description is illustrative only, and the invention includes all variations thereof.

25 Industrial applicability.

The invention described herein is readily applicable to the glass industry and, in particular, the glass fiber industry.

8120396

Claims (39)

1. Laminate in contact with molten glass consisting of a refractory metal substrate and a first oxygen-impermeable precious metal layer, wherein the first layer and the substrate are intimately bonded by the first layer and the substrate being hot isostatic pressed together. The laminate according to claim 1, wherein the refractory metal substrate is at least one material selected from the group consisting of Mo, 3. Laminate according to claim 2, wherein the first layer is an enclosure which completely surrounds the substrate. 4. A method of making a laminate for use in contact with molten inorganic material, comprising providing a refractory metal substrate, forming a precious metal shell of a shape generally corresponding to the shape of the substrate and with oxygen-impermeable walls around the substrate, closing the envelope to form the substrate to form a prelaminate unit, and hot isostatic pressing this unit, to intimately bond the envelope to the substrate to form the laminate. The method of claim 4, wherein the substrate is a material from the group consisting of Mo, 50 Nb, W, V, Hf, Ti, Cr, Ta, Zr, Re, Mn and base alloys thereof, and wherein the shell is a material from the group consisting of Pt, Pd, Ir, Os, Au, Ag, Rh, Ru and base alloys thereof. The method of claim 4, wherein the 55 refractory metal is an alloy of Ti, Zr and Mo. The method of claim 4 or 6, wherein the precious metal layer is an alloy of Pt and Rh. An article manufactured according to the method 8120396 <-38- of claims 4 and 5. 9. In an apparatus with an object in contact with molten inorganic material, the improvement consisting of a refractory metal substrate and an oxygen-impermeable precious metal layer bonded intimately to the substrate by hot isostatic pressing around the article the article having an operating temperature when in contact with the molten material, the melting temperature of the substrate and precious metal layer being greater than the operating temperature, the melting temperature of the lowest melting compound, which is formed between the substrate and the precious metal layer is greater than the operating temperature. The article of claim 9, wherein the product of the expansion coefficient and elastic modulus of the substrate is within the range of about 0.4 to 1.6 times the product of the expansion coefficient and elastic modulus of the precious metal layer. Nb, Hf, Ti, Cr, Ta, Zr, W, V, Re, Mn and base alloys thereof, and wherein the precious metal is at least one material selected from the group consisting of Pt, Pd, Ir, Os , Rh, Au, Ag, Ru and base alloys thereof. 11. In an apparatus for forming glass fibers having a glass feeder with an apertured wall suitable for discharging a stream of glass, the improvement in that the wall is provided with a refractory metal core with opposed precious metal plates, which are hot isostatically pressed to connect the plates to the core with the diffusion connection. 12. Laminated wall for a glass flow feeder to be drawn into fibers, comprising a refractory metal core with an oxygen-impermeable precious metal sheath intimately bonded thereto by hot isostatic pressing to form a laminate wherein the laminate has at least one opening extending therethrough and capable of flowing the molten glass therethrough. 13. Laminated wall for a feeder for feeding glass streams to be drawn out into fibers, comprising a refractory 40 metal core with an oxygen impermeable 8: C <3 ίι * »-39- precious metal casing intimately connected thereto by hot isostatic pressing to form a laminate which laminate has at least one opening extending therethrough and capable of flowing the molten glass therethrough, and an element, which is placed in the opening to prevent the oxidation of the core at high temperatures. Supply member wall according to claim. 13, wherein the element has end faces connected to the inner faces of the case. 15. Feeder wall according to claim 13, wherein the element is a tubular part with a sleeve having a protrusion extending beyond a first flange and located between the first flange and the second flange, the tubular part being bonded to the laminate to prevent oxidation of the core at high temperatures. Feeder wall according to claim 13, wherein the element has a flange at each end thereof connected to the casing, each flange being between the casing and the core, the element being capable of flowing the molten material therethrough . 17. Feeder wall according to claim 13, 14, 15 or 16, wherein the element is made of precious metal. The feeder wall of claim 13, wherein the element has a flange at each end thereof connected to the case, the element having an opening extending therethrough. Feeder wall according to claim 18, wherein the flanges are connected to the outside of the casing. 20. Feeder wall according to claim 18, further comprising a tubular member which communicates with the opening to form the glass streams. Feeder wall according to claim 13, 14, 15 or 16, wherein the core consists of material selected from the group consisting of Ti, V, Nb, Ta, Cr, Mo, W, Re and base alloys thereof and in which the sheath 40 consists of a material from the group consisting of Pt, Pd, Ir, Os, 8120396 t * -40- Th, Ru and base alloys thereof. Feeder wall according to claim 13, 14, 15 or 16, wherein the refractory metal is an alloy of Mo, Ti and Zr. 5 Feeder wall according to claim 13, 14 or 16, further comprising a precious metal element located in an opening in the core, the element having at least one opening suitable for the molten material to flow therethrough, the element being bonded to the precious metal shell to prevent oxidation of the core at high temperatures. The feeder wall of claim 23, further comprising a hollow tubular member, which is attached to the laminate at the opening to form the material streams. The feeder wall of claim 14, wherein the end faces are substantially smooth with the outside of the core. 20 The feeder wall of claim 15, wherein the sleeve projection is oriented to project outwardly from the wall into the fiber-forming zone. The feeder wall of claim 15, wherein the tubular member is intimately joined to the tubular member laminate and the laminate is hot isostatically pressed. 28. A method of making a laminated wall for an inorganic fiber feeder, comprising providing a refractory metal core, wherein a precious metal shell is formed around the core with a shape formed in the core. generally corresponding to the shape of the core, the core and the shell are hot isostatically pressed to intimately bond the shell to the core to form a laminate and at least one opening is formed through the laminate and an element is placed therein, suitable for flowing molten inorganic material therethrough to form the feeder wall. The method of claim 28, wherein the element has a flange adjacent to the casing. s 1 2 0 3 9 6 -41- f The method of claim 28, wherein the laminate is joined to a hollow tubular member adapted to form the flow of the molten inorganic material therethrough. The method of claim 30, wherein the shaft is intimately bonded to the laminate by hot isostatically pressing the element and the laminate together. Supply wall member manufactured by the method according to claim 28, 29, 31, 34 or 35. A method according to claim 28, wherein an opening is formed in the element after the core and sheath have been hot isostatically pressed together. 34. Method according to claim 28, wherein the element is placed in the opening, in that a part is slid into the opening with a sleeve with a projection protruding past a first flange, so that first the flange is in contact with the envelope, a second flange is formed on the sleeve in contact with the casing and the tubular member is joined to the laminate to prevent the oxidation of the core at high temperature, the protrusion being capable of forming a flow of molten inorganic material. The method of claim 28, wherein a flange is further formed at each end of the element 25 adjacent the opposite sides of the core. 36. A method of forming glass fibers, wherein a supply means is provided for supplying molten streams of inorganic material to be drawn into fibers, the supply means comprising a refractory metal core with an oxygen impermeable, precious metal casing intimately connected thereto by hot isostatic pressing to form a laminate, the laminate having at least one opening extending therethrough and capable of flowing streams of molten glass therethrough element is placed in this opening to prevent the oxidation of the core at high temperatures, drawing the flows of molten glass into fibers. Glass fibers manufactured by the method 8120396 -42- according to claim 36. The feeder wall according to claim 13, wherein the feeder is at least substantially stationary. 39. Feeder wall according to claim 13, 5 wherein the feeder is rotatable. 6120396