US3834003A - Method of particle ring-rolling for making metal rings - Google Patents

Method of particle ring-rolling for making metal rings Download PDF

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US3834003A
US3834003A US00374184A US37418473A US3834003A US 3834003 A US3834003 A US 3834003A US 00374184 A US00374184 A US 00374184A US 37418473 A US37418473 A US 37418473A US 3834003 A US3834003 A US 3834003A
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ring
specified
rolling
particles
metal
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H Nayar
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Airco Inc
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Airco Inc
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Priority to FR7338668A priority patent/FR2205384B1/fr
Priority to GB5098973A priority patent/GB1405223A/en
Priority to DE2354991A priority patent/DE2354991C3/de
Priority to US05/463,231 priority patent/US3982904A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/14—Both compacting and sintering simultaneously
    • B22F3/15—Hot isostatic pressing
    • B22F3/156—Hot isostatic pressing by a pressure medium in liquid or powder form
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/1208—Containers or coating used therefor
    • B22F3/1216—Container composition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/1208—Containers or coating used therefor
    • B22F3/1258—Container manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/18—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by using pressure rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/10—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of articles with cavities or holes, not otherwise provided for in the preceding subgroups
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S29/00—Metal working
    • Y10S29/031—Pressing powder with other step
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S29/00—Metal working
    • Y10S29/032—Rolling with other step

Definitions

  • PM processes have been proposed for the fabrication and processing of metal parts and products, mainly because of possible economies and desirable characteristics of the product. For example, it has been proposed to encapsulate powdered copper containing oxides within an elongated steel container and hot roll the unit. During this process, the oxides are broken down and oxygen is absorbed by the encapsulating iron shell. The end product, after removal of the shell, is a deoxidized copper strip.
  • Prior PM techniques however, have not insofar as known been successfully used for producing large ring shaped pieces, and particularly rings composed of aluminum, nickel and other alloys.
  • Casting is successfully used for many metals and simple alloys; however, where the alloy composition is complex, large pieces are subject to defects at grain boundaries, non-homogeneity, and other problems resulting in reduced toughness and strength, creep resistance, and the occurrence of incipient melting at temperatures well below the expected solidus temperature for the alloy.
  • Cast aluminum alloy rings for example, are subject to gross macro-segregation.
  • the ring forging method involves preparing a perforated annular blank from a bloom, and hot ring-forging the blank as it is manually rotated on the mandrel of a press or forge hammer.
  • Ring-rolling is frequently the preferred method for ring fabrication, as the rings can be rolled to a closely controlled profile, the material losses are small and the method is efficient and economical.
  • operation within a narrow temperature range is required for all hot ring-rolling of high temperature, high strength super alloys. Material variation of temperature from the set limits results in cracking (high side) or excessive hardness for working (low side).
  • Some alloys are highly prone to crack during ring-rolling due to high tensile stresses generated in the roll gap, i.e., between the driving roll and mandrel. In such cases ring-forging and ring-rolling methods are both used, i.e., prior to ringrolling a separate ring-forging operation is employed for initially expanding the ring.
  • the method of the invention constitutes ring-rolling a workpiece comprising metal particles encapsulated in a toroid or donut-shaped metal container. During rolling, the workpiece is expanded to form a metal ring of the desired diameter, thickness and configuration.
  • the invention when carried out under preselected conditions described herein, is economical, efficient and results in a sound product ring having superior mechanical properties at ordinary working temperatures.
  • a further and related object of the invention is an im proved method of the character above, wherein blended or pre-alloyed metal particles are encapsulated within a ring-shaped container, densified and hot ringrolled to produce an integrated metal ring that retains physical properties of strength and soundness under comparatively high operating temperatures.
  • Another object of this invention is to hot ring-roll metal particles encapsulated with a ring-shaped container at temperatures which are above and below the solidus temperature of the metal particles.
  • FIG. 1 is an explanatory perspective view of a toroidlike metal container prior to filling with metal particles
  • FIG. 2 is a cross-sectional view of the particle-filled container with sealed covering
  • FIG. 3 is a simplified view of a ring-rolling mill with the container and encapsulated powder in process of ring-rolling;
  • FIG. 3A is an enlarged, partly diagrammatic view of the roll gap region of FIG. 3 during a roll pass;
  • FIG. 4 is a view of a super-alloy ring made according to the invention, showing a contoured profile at a test cut in the ring;
  • FIG. 5 is an enlarged cross-sectional view of the ring shown in FIG. 4.
  • the upper plate 18 is welded to the cylinder ends at 28 and 30 in the manner of plate 20 for closing and sealing the top of the cavity.
  • Endplate 18 is provided with a port 34 and tube 32 which will permit the evacuation of the gases from the can and/or the substitution of an inert gas therefore prior to final sealing.
  • the sealed annular workpiece which in substance constitutes a ring-like mass of metal particles encapsulated in a toroidal metal shell, is adapted as described below, to be mounted on the mandrel of a ring-rolling mill, FIG. 3, for rolling and expansion as described later.
  • the ratio of the thickness of the inner cylinder wall 12 to that of the outer cylinder wall 14 is also important. As the inner cylinder ordinarily will experience more deformation during processing then the outer one it must be thicker intially if the finished ring is to have a wall material skin of equal thicknesses on its inside and outside surfaces. It can be readily shown that the relationship should be as follows:
  • the ratio of the thickness of the inner cylinder to the thickness of the outer cylinder be equal to the ratio of the overall outside diameter to the inside diameter, where the final skin thicknesses respectively, are to be substantially equal.
  • the can material should satisfy the following require ments as closely as possible:
  • the thermal conductivity of the can material should be as low as practical. Preferably, the heat conductivity of the can material should not exceed 0.06 calories/sq. cm./C/second.
  • 304 stainless steel has a conductivity figure of but 0.036 calories, as compared with 0.178 calories for low carbon iron (mild steel). This will allow control of hot-working temperatures within the narrow optimum range. This becomes very desirable in fabricating rings of alloys (e.g. IN-l00) which can be fabricated only within a very narrow temperature range. A further advantage is that less can material is required.
  • Weldability It is desirable that the can be easily welded with the strength of the welds at the end plates being sufficient to eliminate the possibility of weld cracking during ring expansion and fabrication.
  • the flow strength of the can material preferably should be nearly equal to the flow strength of the fully dense particle mass at the ring-rolling temperatures. This will minimize the hazard of can opening or cracking during hot ring-rolling and will allow the transfer of applied forces to the particle mass more effectively.
  • Oxidation Resistance This characteristic is important in order to minimize metal loss during heating in gas-fired furnaces, for example without the use of highly protective muffles. It is also desirable that the can material be oxidation resistant to avoid the need for protective atmospheres.
  • the particles dhould be irregular or angular (grit-like) in shape. Such particles are more compressible and more easily sintered than spherical ones. Furthermore, the particle size, size distribution, and shape should provide maximum packing density with or without compaction. In this regard, angular and spherical particles have about equal application.
  • Pre-alloyed particles are, as a rule, preferred. In certain cases, however, blended particles of different compositions may be more desirable since they are usually more compressible, more economical, and more easily sintered to the desired density and strength levels. During ring-rolling, there is a considerable amount of hot deformation and as a result homogenization can take place. Blending also opens the way for producing multiphase, composite rings with a wide range of physical and mechanical properties.
  • a high internal friction coefficient of the particle mass will increase the mass consolidation rate during ring-rolling by restricting the movement (mobility) of the particles. Internal friction is generally increased by the use of blended compositions wherein the particles are of irregular shapes and have high sintered strength and also by the use of high ring-rolling temperatures.
  • the assembled workpiece shown in FIG. 2 may, depending on the materials used in the workpiece and the desired characteristics of the product ring as well as other factors, be subject to one or more process steps prior to hot ring-rolling.
  • gases in the particle-filled cavity can be removed where desired by a vacuum pump (not shown) through the tube 32 and vent opening 34 in the top ring plate 18.
  • the vent tube is suitably sealed off after evacuation. If desired, an inert gas may be introduced into the particle mass prior to sealing of the vent tube.
  • Some densification of the particle mass is generally desirable prior to ring-rolling to impart some tensile strength to the sintered particle mass.
  • the minimum tensile strength should be at least equal to the tensile 6 compaction, and direct sintering will produce sufficient consolidation before hot ring-rolling.
  • a densification step may be necessary. Any of the well known hot or cold densification techniques can be used for giving the particle mass added tensile strength.
  • FIG. 3 shows a conventional form of simple ringrolling mill wherein the workpiece 10 is rolled between the MANDREL and the powered DRIVE ROLL as indicated by the direction arrows, for expanding the workpiece 10 into a ring.
  • the process initially is generally the same as conventional ring-rolling; however, the present invention essentially differs therefrom by processing a particle mass rather than a solid article.
  • ring-rolling mill of FIG. 3 is shown by way of example only, and that different forms of known ring-rolling equipment such as free roll and trap set-ups, multiple rolls, etc. can be used where suitable in practicing the invention.
  • the maximum possible compressive stresses must be applied with minimum possible resultant tensile stresses, and at a temperature compatible with the properties of the specific particle and can material employed.
  • the tensile stresses that can be tolerated during ring-rolling are greatly dependent upon the tensile strength of the encapsulated sintered particle mass.
  • the tensile stresses depend, among other things, on the mandrel diameter and the ring thickness of the particle mass. The larger the diameter of the mandrel and the smaller the particle ring thickness, the lower the resultant tensile stress in the roll gap during ring-rolling. This also means a higher ratio of compressive stress to resultant tensile stress. Under such conditions, the present process can be made to approach the extrusion process, where compressive stresses predominate.
  • the following is a qualitative analysis primarily for the purpose of bringing out the main process features of ring-rolling a toroidal particle mass, or toroidal workpiece, essentially composed of sinterable particles.
  • D is the mandrel diameter
  • t is the ring thickness prior to roll pass
  • I is the ring thickness after roll pass
  • a is a working constant, depending upon the relationship of the diameter of the drive roll to that of the mandrel.
  • the constant a may range between 05 and 1.0, the former value applying where the drive roll and mandrel diameters are equal and the internal diameter of the ring (workpiece) is considerably larger than that of the mandrel.
  • the constant a approaches 10.
  • the thicknesses of the outer and inner walls of the workpiece are considerably less than t so that the canning material simply functions as a carrier of the particle mass into the roll gap.
  • the particle mass is thus drawn into the roll gap at points A and B so as to pass progressively through various stages of densification.
  • Corresponding reduction in thickness of the workpiece takes place, the thickness being I; as indicated, at the end of the roll pass.
  • the particles along the line AB are not subject to compacting pressure until they pass line ACB which as measured from the mid-point of line AB, is distance x therefrom. It can be shown that the approximate value of x is:
  • a being the angle of internal friction of the particle mass.
  • Case I 10 to 20 for hard, uncompacted, spherical and free flowing powder articles such as superalloys;
  • Case ll 40 to 60 for irregular, uncompacted powder particles of ductile metals and alloys of Al, Ni, Cu, Fe, etc.;
  • Case llI 60 to 80 for a highly predensified mass of ductile metals and alloys of Al, Ni, Cu, Fe, etc.
  • Case I D/t t /5At v.
  • Case II D/t t 22At Vl.
  • Case ll] D/r, r,,/l7lAr vu.
  • Equations V, VI and VII above show that D/t for Cases 1 to Ill would exceed values 2.0, 0.45 and 0.06, respectively.
  • the optimum D/t value may necessarily be above 5, for the given examples of t and At above.
  • experience has shown that a hot densification step is highly desirable for increasing the tensile strength and angle a of the mass prior to hot rolling; this brings the optimum ratio D/t to approximately 2 or thereabout.
  • minimum heat loss through the can material and effective stress transmission to the particle mass are very desirable; also, advantageous techniques that can be used here include trap ring-rolling (with contoured drive wheel and mandrel), or the standard four-roll machine for additional compaction near the edges of the ring.
  • a toroid or donut-shaped can of suitable material with one end open;
  • Ring-rolling the filled and sealed can at suitable temperature in one or more stages to produce a sound ring of the desired size, configuration, and micro-structure;
  • Table 1 describes the five cans which were made from 6061 Al alloy pipes and plates (all in. thick). For welding, type 4043 wire was used. The dimensions of all the cans prior to filling with powders were 5 in. ID,
  • Sample 1 did not crack, nor did it open at any weld; Samples 2 and 3 each had a transverse crack. and
  • Ring-rolling was done in a conventional ring-rolling machine as described above. As indicated, sample No.
  • the good containing sample cans were made from 1018 steel results of the ring-rolling of nickel particles are closely seamless pipes with /2 in. wall thickness and I025 steel related to the following factors: /2 in. thick plates), as illustrated in FIG. 2.
  • the nickel particles are relatively fine, and irregu-
  • the Ni particles were compacted to increase the denlar, and compacted to give 57-67 percent density sity and interparticle contact area, and then were and large contact area between particles. Heating heated to develop some sintered tensile strength prior the nickel particles in the can at 2,150F for 1 hour to ring-rolling.
  • the cans were also evacuated of gas is considered to have given considerable tensile prior to sealing. strength to the sintered particle mass.
  • Inco particles are hard not only at room temperature but also at elevated temperature and as they are course and spherical, they are not easily sintered. They are further characterized by high flow strength (even at elevated temperatures), mobility, a high minimum D/t ratio, and low sintered tensile strength.
  • Carts 3 and 4 were ring-forged at 2,200F for determining the effect of hot-densification prior to ringrolling.
  • Sample 3 was ring-forged in three stages and reduced to the final dimensions given in Table V. Due to prolonged heating in a nonprotective atmosphere, about 12 percent of the steel was lost by oxidation.
  • Sample 4 was ring-forged in two stages to a lesser degree and reduced to the final dimensions also listed in the Table. The steel loss was about 6 percent.
  • Can 6 was made from 54 inch thick lnconel 718 plate with overall ID-to-wall thickness ratio larger than that of the steel can samples.
  • the can was evacuated and welded shut with an lnco filler rod. lnco was also used as can material to determine whether its higher strength is helpful in transmitting the applied stresses to the particle mass during ring-rolling.
  • Sample 1 Considering the very limited soaking time and temperature (1 hour at 2,100F) before the first ring-rolling stage, the strength of the particle mass under such mild sintering was accordingly very low. Soaking time between the subsequent three rolling stages was also very low, never. more than a few minutes at 2100F.
  • the mandrel diameter was 4.75 in.
  • the ratio D/t was initially about 3 and gradually raised to about 9 near the end of the 4th (final) rolling stage.
  • the ring was saw-cut and examined after final rolling, the particles were loose, showing little cohesive strength and very little deformation.
  • a minimum D/t ratio of at least 5 is expected at the beginning of ring-rolling, to be gradually raised to above 15 or thereabout near the end of rolling.
  • Sample 2 This sample was ring-rolled the same as sample 1 except for contouring during the last (4th) rolling stage. Its appearance after rolling was good; there were no visible cracks either in the steel shell or welds. The contoured profile readily.
  • the rolled ring (as-cut) and the contoured profile are shown respectively in FIGS. 4 and 5.
  • the ring wall thickness is about 0.9 in. at the ridges and about 0.36 in. at the two intermediate sections, FIG. 5.
  • the D/t ratio is approximately 3.
  • the ratio gradually increases to about 6 by the time the third ring-rolling stage is completed.
  • Sample 1 teaches that in all probability no significant densification has taken place so far.
  • the drive roll was fitted with a contoured ring to give the crosssection shown in FIG. 5.
  • the D/t ratio at sections 2 and 4 is approximately 30, whereas the ratio at sections 1, 3 and 5 is only about 10. The higher D/t ratio at sections 2 and 4 explains the greater densification.
  • Sections 1 and 5 have the same D/t ratio as section 3; however, the applied stresses transmitted to the particle masses in sections 1 and are probably considerably less than those transmitted to the section 3 mass because of the steel end plates. This would account for the densities in sections 1 and 5 being lower than in section 3.
  • top and bottom can plates be thinner and bowed outward; this configuration would transmit stresses to the particle mass more uniformly and effectively.
  • the use of a four-roll machine could provide more uniform compaction, i.e., increase densities at top and bottom of the ring.
  • Sample 3 As shown in Table V, this sample was ringforged to a considerable degree for determining the effect of hotdensification prior to ring-rolling.
  • the ringrolling operation was carried out at a starting temperature of 2180F. After relatively brief rolling, the steel can opened up at several spots along the length of the ring. Failure was directly related to weak regions in the can caused by approximately 20 percent weight loss of the steel shell during heatings prior to ring-forging and ring-rolling due to oxidation; non-uniform thickness of the steel shell developed during ring-forging and nonuniform densification of the lnconel particles mass due to improper ring-forging.
  • Sample 4 This sample behaved like sample 3, except that the can shell opened lengthwise to a lesser degree, and then only during the last stage of ring-rolling. Sample 4 was ring-forged considerably less than sample 3. This resulted in less weight loss of the steel shell due to oxidation; furthermore, the can shell thickness remained more uniform. After rolling, examination showed densification in several regions of the ring.
  • Sample 5 This sample was rolled in the same manner as sample 1.
  • the can was not ring-forged prior to ringrolling.
  • the soaking temperature was lowered to 2,120F during the subsequent two rolling stages.
  • the steel can and the welds came through the ordeal intact even though the final ring ID was 34 in., considerably larger than any other rolled rings. This clearly shows that the steel shell can withstand temperatures at least up to 2120F.
  • the rolled ring was saw-cut and examined for densification of the lnco particles. Densification was poor, due most likely to low temperature (2,120F.) in the last two rolling stages, and to a low D/t ratio. Initially, D/t was only about 3. Only near the last stage did D/t reach 12. which was probably too low for the lower soaking temperature.
  • Sample 6 in this sample the can shell was fabricated from lnconel 718 plate instead of carbon steel. Shell thickness was A inch instead of /2 inch as in the other cans. The overall wall thickness was smaller, and the D/t (approx. was higher during the last rolling stage. It was ring-rolled at higher average temperatures than the others. Only during the last of the four rolling stages did the ring crack lengthwise at one spot. As to overall densification, this sample was the best. A metallographic examination of the cross-section showed that the density of the lnco particle mass was nearly 100 percent in the center section and gradually decreased with increasing distance from the center.
  • a GROUP Vlll A METAL MATRIX Rings consisting of finely-divided carbide particles of the refractory metals, i.e., titanium, tungsten and vanadium bonded together by a Group VIII A metal, iron group, i.e., iron, nickel and cobalt are commercially desirable products.
  • a ring consisting of TiC in a ferrous matrix was obtained by ring-rolling a toroid containing TiC prealloyed powder and a steel powder.
  • the toroid or donut-shaped can was prepared in the following manner:
  • Can material lnconel Can dimensions: Height 5.85 inches, 0D. 11
  • the powder used to produce this ring was manufactured by the Sintercast Division of Chromalloy American Corporation and sold under the Trademark FER- RO-TiC, Grade C. This powder was a blend of 45 percent titanium-carbide (volume) and medium alloy tool steel.
  • the as-received blended powder Prior to compacting in the can, the as-received blended powder was hydrogen treated at 2,150F for 40 minutes, in order to lower the oxygen level.
  • the levels of carbon, oxygen and hydrogen after this treatment were 6.83 percent, 0.706 percent and 0.0079 percent, respectively.
  • the annular interior of the can was then evacuated and simultaneously heated at 550F for approximately 68 hours.
  • the sealed can was ring-rolled in the following manner with a 42 inch drive roll and no trap:
  • the product has achieved a desirable hardness level and degree of uniformity.
  • the hereinbefore ring was obtained by ring-rolling a carefully prepared can in the solid state, i.e., at a temperature below the solidus temperature of the metal matrix material. This ring could also have been obtained by ring-rolling the can at a temperature above the solidus temperature of the metal matrix material.
  • Ring-rolling conducted at a temperature wherein the matrix material is at least partially in the liquid state offers the following advantages over ring-rolling a similar can in the solid state: (a) less force is required for deformation, thereby enabling larger rings to be rolled, and (b) satisfactory wetting of TiC particles by the ferrous base matrix is assured. This provides improved bonding at the carbide metal matrix interface.
  • Ti and Ti-base particles are compressible at room temperature.
  • the procedures developed for ring-rolling of Al and Ni particles described above are considered completely adequate for producing Ti and Ti alloy rings using the PRR process of the invention.
  • the process invention is well suited to many other combinations of particle materials and encapsulating cans for making special rings, including the following:
  • Ti-Be Particles in Ti Can Ti on the outside provides corrosion resistance.
  • Ti-Be composite (Be to Ti ratio could be higher than the conventional Ti-Be composites) provides the high strength-to-density ratio. This combination has unique potential in the manufacture of rings for high speed aircraft.
  • the invention is also applicable to super-alloy rings subject to critical operating conditions, such as those used in engine structures for high speed aircraft.
  • Such rings require high mechanical strength at operating temperatures materially higher than l,500F.
  • superalloy particles ordinarily yield products with a very fine grain size
  • the mechanical strength thereof at high temperatures is lower than for cast-alloy products, for example, wherein grain growth has increased the high temperature strength. Due to the complex nature of many superalloys, adequate grain size cannot be achieved by conventional heat treatments below the solidus temperature.
  • the workpiece When using alloyed particles, the workpiece is heated to a temperature approximating the solidus temperature (for sintering the particle mass), and then ring-rolled to increase the density of the sintered mass. Following the preliminary ring-rolling, the ring is reheated to a point above the solidus temperature, the temperature limit being higher with increased density of the particle mass. Ring-rolling is started at this point and continued until the ring temperature is well below the solidus temperature. The harmful effects of any cast structures in the ring can be eliminated by rolling at a small deformation rate per pass. Heating and ring- I rolling as described above through the solidus temperature range is repeated. The ring is provided with a final heat treatment for stabilizing the grain size and shape.
  • the rings with complex cross-sectional shapes can be produced more easily because (a) the encapsulating containers can be designed to preformed shapes, (b) the porous structure of the particle mass in the can has greater formability than a solid form and (0) higher rolling temperatures can be used due to the more homogeneous microstructure.
  • the anticipated material loss in producing rings according to the invention is less than 20 percent, even with complex shaped rings of advanced alloys.
  • the material loss in the conventional process as the forged billet is transformed into the unfinished ring, ranges from 20 to 50 percent (before final machining).
  • the material loss approaches the 50 percent level in rings made from the more difficultto-work superalloys (e.g., Rene 4i, Udimet 700, Wasploy and IN lOO etc.) and in rings of complex crosssection.
  • alloys with large freezing ranges such as aluminum can be made into rings with savings in labor and materials; also, blending of metal particles allows a wider range of compositions and properties than attainable by other ring fabrication methods.
  • One of the more important advantages is the improved homogeneity in metal rings, especially super alloy rings, achieved by particle ringrolling. This homogeneity is due to each superalloy particle being a highly homogeneous microingot. Segregation of carbides and intermetallic phases of the type commonly found in cast superalloys is on a very fine scale in superalloy particles. Thus, a high degree of homogeneity is present in rings made from superalloy particles; this results in greatly improved hot workability over a wide and higher range of temperatures during ring fabrication, with obvious savings in labor costs.
  • Another advantage is in the use of the method as a development tool or technique. For example, by eliminating the casting and hot forging problems which must be solved each time a new composition is to be evaluated, the invention tends to simplify and reduce the cost of development of new complex superalloys in ring shape.
  • super alloy means a nickel and/or cobalt base alloy used for high temperature service where relatively high stresses (tensile, thermal, vibratory, and shock) are encountered and where oxidation resistance is frequently required.
  • superalloys contain intermetallic formers (Ti, Al, etc.) and solid solution strengthening refractory metals (Cb, Mo, W, Ta, etc.).
  • the major part of the strengthening at high temperatures is due to the precipitation of the so called gamma prime" phase, generally referred to as Ni (Al, Ti).
  • Chromium is present to provide oxidation resistance along with some auxiliary strengthening. Zirconium and boron are added for increased malleability or high temperature creep resistance or both.
  • a metal working system having means for ringrolling an annular workpiece wherein the workpiece is rolled between a rotating mandrel and a drive roll having a larger diameter than that of the mandrel, the method of making a ring which comprises:
  • a. forming a toroid-like encapsulating metal can having an annular cavity
  • the toroidal can comprises essentially two concentric cylinders radially spaced to form the annular cavity, and the ratio of the wall thickness of the inner cylinder to the wall thickness of the outer cylinder prior to ring-rolling, is substantially equal to the ratio of the overall outside diameter of the can to the inside diameter thereof, where the finally rolled wall thicknesses respectively, are to be substantially equal.
  • a blended powder comprising a refractory metal carbide selected from the group consisting of titanium, tungsten and vanadium and a metal selected from the group consisting of iron, nickel and cobalt;
  • Equation IV Equation IV-- 001. 7, line 46, .Col. 7, line t Col. 7, line 4,

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  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Powder Metallurgy (AREA)
US00374184A 1972-11-02 1973-06-27 Method of particle ring-rolling for making metal rings Expired - Lifetime US3834003A (en)

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US00374184A US3834003A (en) 1972-11-02 1973-06-27 Method of particle ring-rolling for making metal rings
FR7338668A FR2205384B1 (cs) 1972-11-02 1973-10-30
GB5098973A GB1405223A (en) 1972-11-02 1973-11-02 Method of particle ring-rolling for making metal rings
DE2354991A DE2354991C3 (de) 1972-11-02 1973-11-02 Verfahren zum Heißpressen von Metall-oder Legierungspulver und Anwendung dieses Verfahrens
US05/463,231 US3982904A (en) 1973-06-27 1974-04-23 Metal rings made by the method of particle ring-rolling

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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982778A (en) * 1975-03-13 1976-09-28 Caterpillar Tractor Co. Joint and process for forming same
US4016008A (en) * 1975-07-31 1977-04-05 The International Nickel Company, Inc. Clad metal tubes
US4343072A (en) * 1978-09-25 1982-08-10 Societe Nouvelle De Roulements Method of manufacturing composite rings for bearings
US4362563A (en) * 1978-12-06 1982-12-07 Diehl Gmbh & Co. Process for the production of metallic formed members
US20040141866A1 (en) * 2003-01-16 2004-07-22 Forsberg Charles W. Manufacture of annular cermet articles
US20060196033A1 (en) * 2003-07-09 2006-09-07 Thomas Ficker Annular composite workpieces and a cold-rolling method for producing said workpieces
CN100458241C (zh) * 2006-12-18 2009-02-04 宁波东联密封件有限公司 轻质硬质合金密封环及其制造方法
WO2013037094A1 (zh) * 2011-09-15 2013-03-21 上海高更高实业有限公司 轻质梯度硬质合金密封环及制造方法
CN103100623A (zh) * 2012-12-12 2013-05-15 贵州航宇科技发展股份有限公司 Tc17钛合金复杂异形截面环形件的辗轧成形方法
CN105563042A (zh) * 2016-01-29 2016-05-11 柳州市安龙机械设备有限公司 硬质合金密封环的加工方法
CN110814352A (zh) * 2019-11-15 2020-02-21 武汉理工大学 空心梯度管件的热压烧结方法
CN118720143A (zh) * 2024-09-02 2024-10-01 北京钢研高纳科技股份有限公司 粉末高温合金环形件的制备方法

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SE452124B (sv) * 1984-06-19 1987-11-16 Kloster Speedsteel Ab Emne till verktygsmatris av kompoundstal och sett att framstella dylikt
FR2687337B1 (fr) * 1992-02-13 1994-04-08 Valtubes Procede de realisation de tubes par travail a chaud de poudres metalliques et tubes ainsi obtenus.
GB0317765D0 (en) 2003-07-30 2003-09-03 Rolls Royce Plc Deformed forging
DE102013007327A1 (de) * 2013-04-27 2014-10-30 Volkswagen Aktiengesellschaft Als Verbundbauteil ausgebildetes Zahnrad, mit einem aus Blech gebildeten Zahnkranzkörper und einem aus Sintermetall gebildeten Radnabenkörper

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2373405A (en) * 1941-02-14 1945-04-10 Callite Tungsten Corp Process of making seamless hollow bodies of refractory metals
US3409973A (en) * 1961-06-27 1968-11-12 Westinghouse Electric Corp Process for producing annular composite members

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2373405A (en) * 1941-02-14 1945-04-10 Callite Tungsten Corp Process of making seamless hollow bodies of refractory metals
US3409973A (en) * 1961-06-27 1968-11-12 Westinghouse Electric Corp Process for producing annular composite members

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982778A (en) * 1975-03-13 1976-09-28 Caterpillar Tractor Co. Joint and process for forming same
US4016008A (en) * 1975-07-31 1977-04-05 The International Nickel Company, Inc. Clad metal tubes
US4343072A (en) * 1978-09-25 1982-08-10 Societe Nouvelle De Roulements Method of manufacturing composite rings for bearings
US4362563A (en) * 1978-12-06 1982-12-07 Diehl Gmbh & Co. Process for the production of metallic formed members
US20040141866A1 (en) * 2003-01-16 2004-07-22 Forsberg Charles W. Manufacture of annular cermet articles
US6811745B2 (en) * 2003-01-16 2004-11-02 Ut-Battelle, Llc Manufacture of annular cermet articles
US20060196033A1 (en) * 2003-07-09 2006-09-07 Thomas Ficker Annular composite workpieces and a cold-rolling method for producing said workpieces
US8161620B2 (en) * 2003-07-09 2012-04-24 Technische Universität Dresden Annular composite workpieces and a cold-rolling method for producing said workpieces
CN100458241C (zh) * 2006-12-18 2009-02-04 宁波东联密封件有限公司 轻质硬质合金密封环及其制造方法
WO2013037094A1 (zh) * 2011-09-15 2013-03-21 上海高更高实业有限公司 轻质梯度硬质合金密封环及制造方法
CN103100623A (zh) * 2012-12-12 2013-05-15 贵州航宇科技发展股份有限公司 Tc17钛合金复杂异形截面环形件的辗轧成形方法
CN103100623B (zh) * 2012-12-12 2014-10-22 贵州航宇科技发展股份有限公司 Tc17钛合金复杂异形截面环形件的辗轧成形方法
CN105563042A (zh) * 2016-01-29 2016-05-11 柳州市安龙机械设备有限公司 硬质合金密封环的加工方法
CN110814352A (zh) * 2019-11-15 2020-02-21 武汉理工大学 空心梯度管件的热压烧结方法
CN118720143A (zh) * 2024-09-02 2024-10-01 北京钢研高纳科技股份有限公司 粉末高温合金环形件的制备方法

Also Published As

Publication number Publication date
DE2354991C3 (de) 1981-09-24
DE2354991B2 (de) 1981-01-29
DE2354991A1 (de) 1974-05-16
GB1405223A (en) 1975-09-10
FR2205384A1 (cs) 1974-05-31
FR2205384B1 (cs) 1976-10-01

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