CA1178828A - Process for producing dispersion strengthened precious metal alloys - Google Patents
Process for producing dispersion strengthened precious metal alloysInfo
- Publication number
- CA1178828A CA1178828A CA000360295A CA360295A CA1178828A CA 1178828 A CA1178828 A CA 1178828A CA 000360295 A CA000360295 A CA 000360295A CA 360295 A CA360295 A CA 360295A CA 1178828 A CA1178828 A CA 1178828A
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- Canada
- Prior art keywords
- ranging
- bushing plate
- hot pressing
- platinum
- vacuum hot
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
- C22C1/1084—Alloys containing non-metals by mechanical alloying (blending, milling)
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
- C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
- C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
- C22C32/0021—Matrix based on noble metals, Cu or alloys thereof
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Powder Metallurgy (AREA)
- Manufacture Of Alloys Or Alloy Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for producing dispersion-strengthened pre-cious metal alloys having superior creep resistance is disclosed.
According to this invention precious metal powders and disper-soids are mechanically alloyed together. High energy ball mill-ing can be used to achieve the mechanical alloying. After the mechanical alloying step, the resulting powder is consolidated by vacuum hot pressing at elevated temperature and pressures.
The precious metal powder can be platinum or a platinum alloy.
The dispersoids can include yttria (Y2O3).
A process for producing dispersion-strengthened pre-cious metal alloys having superior creep resistance is disclosed.
According to this invention precious metal powders and disper-soids are mechanically alloyed together. High energy ball mill-ing can be used to achieve the mechanical alloying. After the mechanical alloying step, the resulting powder is consolidated by vacuum hot pressing at elevated temperature and pressures.
The precious metal powder can be platinum or a platinum alloy.
The dispersoids can include yttria (Y2O3).
Description
2~3 This invention relates to a process for producing dis-persion strengthened precious metal alloys. The present inven-tion can provide alloys containing platinum, palladium, rhodium and gold which are useful in the production o~ glass fibers.
One of the most exacting applications of platinum is in the production of glass fibers. Molten glass often at tem-peratures ranging from 1200 to 1600C passes through a series of orifices in a bushing. Advances in glass fiber production are demanding both larger bushings and higher operating temperatures.
Structural components such as these at elevated tem-peratures under constant loads experience continuous dimensional changes or creep during their lives. This creep behavior depends upon the interaction between the external conditions (load, temperature) and the microstructure of the component. In recent times, increased resistance to creep of material systems has been accomplished by using a dispersion of very small, hard particles (called dispersoids) to strengthen the microstructure of the component. These systems have become to be known as dis-persion-strengthened metals and alloys and the dispersoids used are usually oxides.
A recent development in dispersion-strengthening is called mechanical alloying. Generally, the process uses a high energy ball mill to achieve the intimate mechanical mixing typi-cal of the process. An attritor mill or vibratory mill also can be used. While mechanical alloying has been applied to some of the transition metals, no actual work has been reported on pre-cious metals such as platinum.
The present invention provides a process for producing dispersion-strengthened precious metal alloys having creep re-sistance superior to known dispersion-strengthened platinum 1~7~i8~8 alloys.
According to the process of this invention, a process for producing dispersion strengthened precious metal alloys com-prises the step of mechanically alloying precious metal powder and at least one dispersoid together wherein the dispersoid is present in effective dispersion strengthening amounts.
The mechanical alloying is preferably carried out by a high energy ball mill to achieve the intimate mechanical mixing of this process. The oxide particles are forged into the pre-cious metal matrix powder particle to form a composite powderparticle.
In the drawing, Figure 1, illustrates the internal arrangement in an attritor mill showing the impeller, grinding media and external cooling jacket. Impact events occur in the dynamic interstices of the media created by the impeller during stirring.
There are several high-energy ball mills commercially available either using a stirrer to induce the deformation events or vibratory motion. Figure 1 shows an overall view of the attritor mill 10. The stainless steel bearings or grinding media 12 and the powder charge go into the cylindrical ~ontainer of the mill. The high-energy impacts are effected by the ro-tating impeller 14. Figure 1 also illustrates the internal arrangement in the attritor mill, impact events occur in the dy-namic interstices of the media created by the impeller during stirring.
1~06~ 7~
1 Dispersion strenyt~ened precious metals are kno~n in the art dnd are commercially available. One such m2terial is that available from Johnson, ~dtthey & Co.
Limited, under their designation ZCS. The above indicated 5 ZGS rnateridl consists essentially of platinum in ~hich the disperoid is zirconia; the latter is present in an amount of about 0.5~. by volume.
Tne dispersion strengthened precious metals of this invention generally comprise a precious metal, or 10 precious metal alloy, preferably platinum, as the dispersing medium, or matrix, and a dispersoid of a metal oxide, metal carbide, metal silicide, metal nitride, metal sulfide or d metal boride which dispersoid is present in effe~ctive dispersion strengthening amounts. Usually such 15 amounts will be between about U.l percent to about 5.0 percent by volurne. Preferably the dispersoid ~Jill be an oxide. Exemplary of metal compounds which may be employed as the dispersoid are compounds of metals of Group IIA, IIIA, IIIB (including non-hazardous metals of the Actinide 20 and Lanthanide classes), IVB, VB, VIB and VIIB. More specifically exemplary of sui~able metals are the following: Be, Mg, Ca, Ba, Y, La, Ti, Zr, Hf, Mo, W, Ce, Nd, Gd, and Th as well as Al.
Several rnechanical alloying experiments were 25 performed using the attritor mill to generate a composite powder for consolidation. Wash heats intended to coat a thin layer of platinum on the internal workings surfaces of the attritor mill were carried out. This "conditioning"
treatment was intended to prevent iron contamination of subsequent milling experiments, but several washes were re4uired before the iron contamination was reduced to what was believed to be an acceptable level.
The samples then are consolidated by vacuum hot pressing ~VHP) at elevated temperatures and pressures. In 35 the alternative, the samples can be consolidated by first cold pressing at elevated pressures followed by sintering dt elevated temperatures. VHP generally is carried out at , .
.
.
:
1 a temperaturc ranying fron 1300 to 1700C under a pressure ranging from 500 to 10,C00 psi for a time ranging from 10 to 30 minutes. Preferably, the temperature ranges from 1400 to 15U0C under a pressure of 3,000 ~o 6,Q0~ psi for a 5 time of 15 to 25 minutes. Generally, the cold pressing is carried out at 3 pressure ranging from ~,Q00 to 10,000 psi for up to 5 minutes followed by sintering at a tPmperature ranginy from 1200 to 1700C for 2 to 6 hours.
EXA~PLE I
Approximately one kgm of -325 mesh (-44 micron) platinum sponge from Englehard WdS blended with an amount of yttria (Y203) to giv~ nominally 0.65 volume percent (0.15 weight percent3 oxide loading in the final compact.
The yttria was 200-600 angstrom in size. The platinum 15 matrix starting powder for the experiment consisted of very fine, near spherical particles or chdined aggregates. Most of the particles below 2 microns appeared to be single crystals. The starting powder had a fairly high specific surface area.
The powder mixture was charged into the container of the attritor mill while it was running. The grinding media had ~een previously loaded to give a volume ratio of rnedia to powder of about 20:1. The grinding media used was a hardened 400 series stainless steel bearing 25 nominally 3/8 inch (0.953 cm) diameter. The impeller rotational speed was selected at 130 rpm.
Samples of powder were removed at various times to obtain information on the changes in particle nlorphology and specific surface area with milling time. The first 30 sample WdS taken after one hour of milling and indicated that flake generation was in progress.
After milling for three hours, another powder sample was taken for metallographic characterization.
~hile rnore flakes were yenerated, the extent of plastic deformation seemed to have increased. Flake cold welding dppeared to have taken place as well. Tne composite flake appeared to have three or four component flakes cold welded togethex. No edge cracking appeared in the composite flake sug-gesting that work hardening saturation had not been reached at this point.
After milling for 23 hours, the composite flakes appear-ed to thicken. This clearly demonstrates the cold welding aspect of the milling action. Along with cold welding, the flake diame-ter appeared to increase.
The experiment was continued for 71 hours then terminat-ed, and the powder was removed for further processing.
There appeared to be a ~airly high initial surface a-rea generation rate. The iron contamination in the milled pow-der was greatly reduced compared to the previous experiments and reflects the coating action that appeared to minimize wear debris generation during milling. The maximum iron contamination level in the powder was approximatel~ 300 wppm. The milled powder was consolidated by vacuum hot pressing and thermomechanically pro-cessing into sheet for creep testing, the details are to follow.
EXAMPLE II
Example I produced a powder of relatively low iron con-tamination. Since this experiment resulted in small powder lots(nominally 80 gms) taken at various times during the milling ex-periment, each sample was individually consolidated by vacuum hot pressing (VHP) at 1,450 C under 5,000 psi (34.5 MN/m ) for twenty minutes. The resultant compacts were nominally 1 inch (2.54 cm) in diameter.
Relative density of specimens are listed.
Specimen Milling Time (hr.) Relative Density (~) A 0 95.2 B 1 98.2 30 C 2.5 99.8 D 6 99.8 . -- 5 --"'~-."' ~.17~
The thermomechanical processing (TMP) schedule used on the compact consisted of several roll/anneal cycles. The basic operation involved rolling a sheet specimen and cropping pieces after various rolling passes - 5a -I~vo3A -6-1 for rnicrostructural characterization. The procedure used was to roll the compact for d 10 percent reduction in area then anneal the rolled specimen for five minutes a~
nominal'ly 1,040C before further rolling.
Specimen D was the most responsive to the TMP
cycles. After the 10th rolling pass, the grain structure was fairly elongated. The lack of oxide clusters during optica1 metdlloyraphic eXamindtiOn suggested that the milling action had worked the yttria into the platinum 10 Illatrix- A me~tdlloyraphic analysis of the same region showed the development of d moderate grain aspect ratio (grain length to thickness ratio in the viewing plane). As the number of roll/anneal cycles increased, the grain aspect ratio (GAR) increased. At this stage a moderate GAR
15 also had been developed in a transverse direction. The significance of this observation is that the grains took on the shape of a pancake structure thin in a direction perpendiculdr to the sheet yet extended in the other two directions. Since a GAR seems to extend in two directions 2~ in the rolled sheet and the state of stress in a bushing tip plate is biaxial, this tr~rsverse GAR development may be very benef'icial for good creep resistance in bushing applications.
After the 16th rolling pdSS, the elongation of 25 the grains had increased significantly. A higher m~gnifio~tion view of the same region revealed the de3ree of grain elongation and fineness of the grain size. The transverse GAR had a'lso significantly increased. These elongated grain morphologies are desirable microstructures 30 for good creep resistance.
INDUSTRIAL APPLICABILITY
EXAMPLE III
Creep Testing All the creep testing was done in air using constant load machines, the elongation ~as measured by an LVDT connected to a multi-point recorder and a precision digital voltmeter. Specimen temperature was monitored with 1 ~,0~
1 a calibrated Pt/Pt-Rh thermocouple attached so that the bead was adjacent to the gage section of the creep specimen. The creep specimen WdS a flat plate type with a gage lenyth of approximately 2.25 inch (5.72 crn). The 5 tensile stress was applied parallel to the rolling direction (longitudinal direction). The yeneral procedure was to hang the specimen in the furance to reach thermal equilibrium then start the rig timer upon application of the load. Periodic temperature and extension measurements 10 were made eitner until the specimen failed or the test was terminated (specimen rerlloval or furnace burn-out).
Creep results were obtained from specimens that were processed according to Example II except that these specimens were milled 10 hours and received the above 15 thermomecnanical processing treatment of 10% reduction in area per pass with an intermediate anneal at nominally 1040C for 5 minutes. The extent of deformation was nominally an ~5% reduction in area. The first specimen had a varied creep history that started by applying a tensile 20 stress of 1,C00 psi (6.~9 Mn/m2) at 2,400F (1,316C). The resultant secondary creep rate was too low to adequately measure; therefore, the temperature was increased to 2,600F (1,427C) and a secondary creep rate of 4.5x10-6 hr 1 was observed. After approximately 118 hours the 25 stress was increased to 1,400 psi (9.65 Mn/m2) and a new secondary creep rate of nominally 3x10 5 hr 1 was recorded.
These creep rates are two orders of magnitude less than that for the previously indicated ZGS under the same testing conditions. The ~GS material will have a stress rupture life of at least 48 hours when tested at l400C and lO00 psi in the rolling direction of the sheet.
The general microstructure of the crept specirnen indicated that the yrains were highly elongated in the rolliny direction ~creep stress direction also) and the grain boundries were ragged. There appeared to be evidence of subgrains in the structure as well. The microstructure observed in this specimen ~!as typical of that of a good
One of the most exacting applications of platinum is in the production of glass fibers. Molten glass often at tem-peratures ranging from 1200 to 1600C passes through a series of orifices in a bushing. Advances in glass fiber production are demanding both larger bushings and higher operating temperatures.
Structural components such as these at elevated tem-peratures under constant loads experience continuous dimensional changes or creep during their lives. This creep behavior depends upon the interaction between the external conditions (load, temperature) and the microstructure of the component. In recent times, increased resistance to creep of material systems has been accomplished by using a dispersion of very small, hard particles (called dispersoids) to strengthen the microstructure of the component. These systems have become to be known as dis-persion-strengthened metals and alloys and the dispersoids used are usually oxides.
A recent development in dispersion-strengthening is called mechanical alloying. Generally, the process uses a high energy ball mill to achieve the intimate mechanical mixing typi-cal of the process. An attritor mill or vibratory mill also can be used. While mechanical alloying has been applied to some of the transition metals, no actual work has been reported on pre-cious metals such as platinum.
The present invention provides a process for producing dispersion-strengthened precious metal alloys having creep re-sistance superior to known dispersion-strengthened platinum 1~7~i8~8 alloys.
According to the process of this invention, a process for producing dispersion strengthened precious metal alloys com-prises the step of mechanically alloying precious metal powder and at least one dispersoid together wherein the dispersoid is present in effective dispersion strengthening amounts.
The mechanical alloying is preferably carried out by a high energy ball mill to achieve the intimate mechanical mixing of this process. The oxide particles are forged into the pre-cious metal matrix powder particle to form a composite powderparticle.
In the drawing, Figure 1, illustrates the internal arrangement in an attritor mill showing the impeller, grinding media and external cooling jacket. Impact events occur in the dynamic interstices of the media created by the impeller during stirring.
There are several high-energy ball mills commercially available either using a stirrer to induce the deformation events or vibratory motion. Figure 1 shows an overall view of the attritor mill 10. The stainless steel bearings or grinding media 12 and the powder charge go into the cylindrical ~ontainer of the mill. The high-energy impacts are effected by the ro-tating impeller 14. Figure 1 also illustrates the internal arrangement in the attritor mill, impact events occur in the dy-namic interstices of the media created by the impeller during stirring.
1~06~ 7~
1 Dispersion strenyt~ened precious metals are kno~n in the art dnd are commercially available. One such m2terial is that available from Johnson, ~dtthey & Co.
Limited, under their designation ZCS. The above indicated 5 ZGS rnateridl consists essentially of platinum in ~hich the disperoid is zirconia; the latter is present in an amount of about 0.5~. by volume.
Tne dispersion strengthened precious metals of this invention generally comprise a precious metal, or 10 precious metal alloy, preferably platinum, as the dispersing medium, or matrix, and a dispersoid of a metal oxide, metal carbide, metal silicide, metal nitride, metal sulfide or d metal boride which dispersoid is present in effe~ctive dispersion strengthening amounts. Usually such 15 amounts will be between about U.l percent to about 5.0 percent by volurne. Preferably the dispersoid ~Jill be an oxide. Exemplary of metal compounds which may be employed as the dispersoid are compounds of metals of Group IIA, IIIA, IIIB (including non-hazardous metals of the Actinide 20 and Lanthanide classes), IVB, VB, VIB and VIIB. More specifically exemplary of sui~able metals are the following: Be, Mg, Ca, Ba, Y, La, Ti, Zr, Hf, Mo, W, Ce, Nd, Gd, and Th as well as Al.
Several rnechanical alloying experiments were 25 performed using the attritor mill to generate a composite powder for consolidation. Wash heats intended to coat a thin layer of platinum on the internal workings surfaces of the attritor mill were carried out. This "conditioning"
treatment was intended to prevent iron contamination of subsequent milling experiments, but several washes were re4uired before the iron contamination was reduced to what was believed to be an acceptable level.
The samples then are consolidated by vacuum hot pressing ~VHP) at elevated temperatures and pressures. In 35 the alternative, the samples can be consolidated by first cold pressing at elevated pressures followed by sintering dt elevated temperatures. VHP generally is carried out at , .
.
.
:
1 a temperaturc ranying fron 1300 to 1700C under a pressure ranging from 500 to 10,C00 psi for a time ranging from 10 to 30 minutes. Preferably, the temperature ranges from 1400 to 15U0C under a pressure of 3,000 ~o 6,Q0~ psi for a 5 time of 15 to 25 minutes. Generally, the cold pressing is carried out at 3 pressure ranging from ~,Q00 to 10,000 psi for up to 5 minutes followed by sintering at a tPmperature ranginy from 1200 to 1700C for 2 to 6 hours.
EXA~PLE I
Approximately one kgm of -325 mesh (-44 micron) platinum sponge from Englehard WdS blended with an amount of yttria (Y203) to giv~ nominally 0.65 volume percent (0.15 weight percent3 oxide loading in the final compact.
The yttria was 200-600 angstrom in size. The platinum 15 matrix starting powder for the experiment consisted of very fine, near spherical particles or chdined aggregates. Most of the particles below 2 microns appeared to be single crystals. The starting powder had a fairly high specific surface area.
The powder mixture was charged into the container of the attritor mill while it was running. The grinding media had ~een previously loaded to give a volume ratio of rnedia to powder of about 20:1. The grinding media used was a hardened 400 series stainless steel bearing 25 nominally 3/8 inch (0.953 cm) diameter. The impeller rotational speed was selected at 130 rpm.
Samples of powder were removed at various times to obtain information on the changes in particle nlorphology and specific surface area with milling time. The first 30 sample WdS taken after one hour of milling and indicated that flake generation was in progress.
After milling for three hours, another powder sample was taken for metallographic characterization.
~hile rnore flakes were yenerated, the extent of plastic deformation seemed to have increased. Flake cold welding dppeared to have taken place as well. Tne composite flake appeared to have three or four component flakes cold welded togethex. No edge cracking appeared in the composite flake sug-gesting that work hardening saturation had not been reached at this point.
After milling for 23 hours, the composite flakes appear-ed to thicken. This clearly demonstrates the cold welding aspect of the milling action. Along with cold welding, the flake diame-ter appeared to increase.
The experiment was continued for 71 hours then terminat-ed, and the powder was removed for further processing.
There appeared to be a ~airly high initial surface a-rea generation rate. The iron contamination in the milled pow-der was greatly reduced compared to the previous experiments and reflects the coating action that appeared to minimize wear debris generation during milling. The maximum iron contamination level in the powder was approximatel~ 300 wppm. The milled powder was consolidated by vacuum hot pressing and thermomechanically pro-cessing into sheet for creep testing, the details are to follow.
EXAMPLE II
Example I produced a powder of relatively low iron con-tamination. Since this experiment resulted in small powder lots(nominally 80 gms) taken at various times during the milling ex-periment, each sample was individually consolidated by vacuum hot pressing (VHP) at 1,450 C under 5,000 psi (34.5 MN/m ) for twenty minutes. The resultant compacts were nominally 1 inch (2.54 cm) in diameter.
Relative density of specimens are listed.
Specimen Milling Time (hr.) Relative Density (~) A 0 95.2 B 1 98.2 30 C 2.5 99.8 D 6 99.8 . -- 5 --"'~-."' ~.17~
The thermomechanical processing (TMP) schedule used on the compact consisted of several roll/anneal cycles. The basic operation involved rolling a sheet specimen and cropping pieces after various rolling passes - 5a -I~vo3A -6-1 for rnicrostructural characterization. The procedure used was to roll the compact for d 10 percent reduction in area then anneal the rolled specimen for five minutes a~
nominal'ly 1,040C before further rolling.
Specimen D was the most responsive to the TMP
cycles. After the 10th rolling pass, the grain structure was fairly elongated. The lack of oxide clusters during optica1 metdlloyraphic eXamindtiOn suggested that the milling action had worked the yttria into the platinum 10 Illatrix- A me~tdlloyraphic analysis of the same region showed the development of d moderate grain aspect ratio (grain length to thickness ratio in the viewing plane). As the number of roll/anneal cycles increased, the grain aspect ratio (GAR) increased. At this stage a moderate GAR
15 also had been developed in a transverse direction. The significance of this observation is that the grains took on the shape of a pancake structure thin in a direction perpendiculdr to the sheet yet extended in the other two directions. Since a GAR seems to extend in two directions 2~ in the rolled sheet and the state of stress in a bushing tip plate is biaxial, this tr~rsverse GAR development may be very benef'icial for good creep resistance in bushing applications.
After the 16th rolling pdSS, the elongation of 25 the grains had increased significantly. A higher m~gnifio~tion view of the same region revealed the de3ree of grain elongation and fineness of the grain size. The transverse GAR had a'lso significantly increased. These elongated grain morphologies are desirable microstructures 30 for good creep resistance.
INDUSTRIAL APPLICABILITY
EXAMPLE III
Creep Testing All the creep testing was done in air using constant load machines, the elongation ~as measured by an LVDT connected to a multi-point recorder and a precision digital voltmeter. Specimen temperature was monitored with 1 ~,0~
1 a calibrated Pt/Pt-Rh thermocouple attached so that the bead was adjacent to the gage section of the creep specimen. The creep specimen WdS a flat plate type with a gage lenyth of approximately 2.25 inch (5.72 crn). The 5 tensile stress was applied parallel to the rolling direction (longitudinal direction). The yeneral procedure was to hang the specimen in the furance to reach thermal equilibrium then start the rig timer upon application of the load. Periodic temperature and extension measurements 10 were made eitner until the specimen failed or the test was terminated (specimen rerlloval or furnace burn-out).
Creep results were obtained from specimens that were processed according to Example II except that these specimens were milled 10 hours and received the above 15 thermomecnanical processing treatment of 10% reduction in area per pass with an intermediate anneal at nominally 1040C for 5 minutes. The extent of deformation was nominally an ~5% reduction in area. The first specimen had a varied creep history that started by applying a tensile 20 stress of 1,C00 psi (6.~9 Mn/m2) at 2,400F (1,316C). The resultant secondary creep rate was too low to adequately measure; therefore, the temperature was increased to 2,600F (1,427C) and a secondary creep rate of 4.5x10-6 hr 1 was observed. After approximately 118 hours the 25 stress was increased to 1,400 psi (9.65 Mn/m2) and a new secondary creep rate of nominally 3x10 5 hr 1 was recorded.
These creep rates are two orders of magnitude less than that for the previously indicated ZGS under the same testing conditions. The ~GS material will have a stress rupture life of at least 48 hours when tested at l400C and lO00 psi in the rolling direction of the sheet.
The general microstructure of the crept specirnen indicated that the yrains were highly elongated in the rolliny direction ~creep stress direction also) and the grain boundries were ragged. There appeared to be evidence of subgrains in the structure as well. The microstructure observed in this specimen ~!as typical of that of a good
3~ 7 1 creep resistant material as evidenced by the exceptionally good creep properties.
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Claims (17)
1. A bushing plate for glass fiber production, form-ed of a dispersion strengthened precious metal alloy, predo-minantly comprising platinum or a platinum alloy containing a metal oxide dispersoid in an effective dispersion-strengthen-ed amount of from 0.1 to 5% by volume, the bushing alloy having been produced by mechanically alloying together the precious metal powder of platinum or a platinum alloy and the metal oxide powder, and consolidating the resulting mechanically alloyed powder by vacuum hot pressing at elevated temperature and pressure.
2. A bushing plate according to claim 1, wherein the dispersoid includes yttria (Y203).
3. A bushing plate according to claims 1 or 2, where-in high energy ball milling has been used to achieve the mecha-nical alloying.
4. A bushing plate according to claim 1 or 2, where-in the amount of yttria is about 0.65 percent by volume (0.15 percent by weight).
5. A bushing plate according to claim 1 or 2, where-in the vacuum hot pressing has been carried out at a tempera-ture ranging from 1300 to 1700°C under a pressure ranging from 500 to 10,000 psi for a time ranging from 10 to 30 minutes.
6. A bushing plate according to claim 1 or 2, where-in the vacuum hot pressing has been carried out at a tempera-ture ranging from 1400 to 1500°C under a pressure ranging from 3,000 to 6,000 psi for a time ranging from 15 to 25 minutes.
7. A bushing plate according to claim l or 2, where-in the vacuum hot pressing has been carried out at a tempera-ture of about 1,450°C under a pressure of about 5,000 psi for a time of about twenty minutes.
8. A process for producing a bushing plate formed of a dispersion-strengthened precious metal alloy comprising the steps of:
(l) mechanically alloying together precious metal powder of platinum or platinum alloy and at least one dispersoid of a metal oxide, wherein the dispersoid is present in an effective dispersion-strengthened amount of from 0.1 to 5%
by volume;
(2) consolidating the resulting powder by vacuum hot pressing at elevated temperature and pressures; and (3) forming the product into a bushing plate.
(l) mechanically alloying together precious metal powder of platinum or platinum alloy and at least one dispersoid of a metal oxide, wherein the dispersoid is present in an effective dispersion-strengthened amount of from 0.1 to 5%
by volume;
(2) consolidating the resulting powder by vacuum hot pressing at elevated temperature and pressures; and (3) forming the product into a bushing plate.
9. A process according to claim 8 wherein the dis-persoid includes yttria (Y203).
10. A process according to claims 1 or 2 wherein high energy ball milling is used to achieve the mechanical alloying.
11. A process for producing a bushing plate for glass fiber production, comprising the steps of:
(1) mechanically alloying platinum powder and yttria (Y203) together wherein the yttria is present in effective dispersion strengthening amounts;
(2) consolidating the resulting powder by vacuum hot pressing at elevated temperatures and pressures to form a dispersion strengthened platinum alloy; and forming the alloy into a bushing plate.
(1) mechanically alloying platinum powder and yttria (Y203) together wherein the yttria is present in effective dispersion strengthening amounts;
(2) consolidating the resulting powder by vacuum hot pressing at elevated temperatures and pressures to form a dispersion strengthened platinum alloy; and forming the alloy into a bushing plate.
12. A process according to claim 11 wherein the amount of yttria ranges between 0.1 to 5.0 percent by volume.
13. A process according to claim 11 wherein the amount of yttria is about 0.65 percent by volume (0.15 percent by weight).
14. A process according to claim 11 wherein the vacuum hot pressing is carried out at a temperature ranging from 1300 to 1700°C under a pressure ranging from 500 to 10,000 psi for a time ranging from 10 to 30 minutes.
15. A process according to claim 11 wherein the vacuum hot pressing is carried out at a temperature ranging from 1400 to 1500°C under a pressure ranging from 3,000 to 6,000 psi for a time ranging from 15 to 25 minutes.
16. A process according to claim 11 wherein the vacuum hot pressing is carried out at a temperature of about 1,450°C under a pressure of about 5,000 psi for a time of about twenty minutes.
17. A process according to claim 11 wherein high energy ball milling is used to achieve the mechanical alloying.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US8172379A | 1979-10-04 | 1979-10-04 | |
| US081,723 | 1979-10-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1178828A true CA1178828A (en) | 1984-12-04 |
Family
ID=22165981
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000360295A Expired CA1178828A (en) | 1979-10-04 | 1980-09-16 | Process for producing dispersion strengthened precious metal alloys |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS56501456A (en) |
| CA (1) | CA1178828A (en) |
| GB (1) | GB2075553A (en) |
| SE (1) | SE8103480L (en) |
| WO (1) | WO1981000977A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4536202A (en) * | 1983-12-06 | 1985-08-20 | Owens-Corning Fiberglas Corporation | Drain bushing |
| US4518406A (en) * | 1983-12-06 | 1985-05-21 | Owens-Corning Fiberglas Corporation | Drain bushing |
| DE4417495C1 (en) * | 1994-05-19 | 1995-09-28 | Schott Glaswerke | Prodn. of pure platinum materials reinforced with yttrium oxide |
| DE10046456C2 (en) | 2000-09-18 | 2003-04-10 | Heraeus Gmbh W C | Through finely divided, small particles of base metal oxide, dispersion-strengthened, gold-free platinum material |
| BRPI0514280A (en) * | 2004-08-26 | 2008-06-10 | Umicore Ag & Co Kg | processes for the production of dispersoid reinforced material |
| CN100507041C (en) * | 2004-10-08 | 2009-07-01 | 田中贵金属工业株式会社 | Oxide-dispersed alloy platinum material |
| CN101758227B (en) * | 2008-09-30 | 2011-10-26 | 王惠民 | Nanometer iron powder special for shielding electromagnetic wave and radar wave in glass cockpit of airplane |
| JP4965696B2 (en) * | 2010-10-21 | 2012-07-04 | 田中貴金属工業株式会社 | Method for producing oxide dispersion strengthened platinum alloy |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1139897A (en) * | 1965-01-15 | 1969-01-15 | Johnson Matthey Co Ltd | Improvements in and relating to the treatment of platinum group metals and alloys |
| US3738817A (en) * | 1968-03-01 | 1973-06-12 | Int Nickel Co | Wrought dispersion strengthened metals by powder metallurgy |
| US3591362A (en) * | 1968-03-01 | 1971-07-06 | Int Nickel Co | Composite metal powder |
| US3623849A (en) * | 1969-08-25 | 1971-11-30 | Int Nickel Co | Sintered refractory articles of manufacture |
| GB1559647A (en) * | 1976-09-07 | 1980-01-23 | Special Metals Corp | Method of making oxide dispersion strengthened metallic powder |
-
1980
- 1980-08-18 JP JP50220280A patent/JPS56501456A/ja active Pending
- 1980-08-18 GB GB8112100A patent/GB2075553A/en not_active Withdrawn
- 1980-08-18 WO PCT/US1980/001061 patent/WO1981000977A1/en unknown
- 1980-09-16 CA CA000360295A patent/CA1178828A/en not_active Expired
-
1981
- 1981-06-03 SE SE8103480A patent/SE8103480L/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2075553A (en) | 1981-11-18 |
| JPS56501456A (en) | 1981-10-08 |
| WO1981000977A1 (en) | 1981-04-16 |
| SE8103480L (en) | 1981-06-03 |
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