Powder metallurgy processes – Powder metallurgy processes with heating or sintering – Powder pretreatment
Reexamination Certificate
2000-03-24
2001-09-25
Mai, Ngoclan (Department: 1742)
Powder metallurgy processes
Powder metallurgy processes with heating or sintering
Powder pretreatment
C419S028000, C419S029000, C419S043000, C148S514000, C148S557000, C148S688000, C148S695000
Reexamination Certificate
active
06294130
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to manufacture of metallic products such as sheet, strip, rod, wire or band, especially of difficult-to-work intermetallic alloys like aluminides of iron, nickel and titanium.
BACKGROUND OF THE INVENTION
Fe
3
Al intermetallic iron aluminides having a body centered cubic ordered crystal structure are disclosed in U.S. Pat. Nos. 5,320,802; 5,158,744; 5,024,109; and 4,961,903. An iron aluminide alloy having a disordered body centered crystal structure is disclosed in U.S. Pat. No. 5,238,645 wherein the alloy includes, in weight % 8-9.5 Al, ≦7 Cr, ≦4 Mo, ≦0.05 C, ≦0.5 Zr and ≦0.1 Y, preferably 4.5-5.5 Cr, 1.8-2.2 Mo, 0.02-0.032 C and 0.15-0.25 Zr.
Iron-base alloys containing 3-18 wt % Al, 0.05-0.5 wt % Zr, 0.01-0.1 wt % B and optional Cr, Ti and Mo are disclosed in U.S. Pat. No. 3,026,197 and Canadian Patent No. 648,140. U.S. Pat. No. 3,676,109 discloses an iron-base alloy containing 3-10 wt % Al, 4-8 wt % Cr, about 0.5 wt % Cu, less than 0.05 wt % C, 0.5-2 wt % Ti and optional Mn and B.
Iron-base aluminum containing alloys for use as electrical resistance heating elements are disclosed in U.S. Pat. Nos. 1,550,508; 1,990,650; and 2,768,915 and in Canadian Patent No. 648,141. The alloys disclosed in the '508 patent include 20 wt % Al, 10 wt % Mn; 12-15 wt % Al, 6-8 wt % Mn; or 12-16 wt % Al, 2-10 wt % Cr. All of the specific examples disclosed in the '508 patent include at least 6 wt % Cr and at least 10 wt % Al. The alloys disclosed in the '650 patent include 16-20 wt % Al, 5-10 wt % Cr, ≦0.05 wt % C, ≦0.25 wt % Si, 0.1-0.5 wt % Ti, ≦1.5 wt % Mo and 0.4-1.5 wt % Mn and the only specific example includes 17.5 wt % Al, 8.5 wt % Cr, 0.44 wt % Mn, 0.36 wt % Ti, 0.02 wt % C and 0.13 wt % Si. The alloys disclosed in the '915 patent include 10-18 wt % Al, 1-5 wt % Mo, Ti, Ta, V, Cb, Cr, Ni, B and W and the only specific example includes 16 wt % Al and 3 wt % Mo. The alloys disclosed in the Canadian patent include 6-11 wt % Al, 3-10 wt % Cr, ≦4 wt % Mn, ≦1 wt % Si, ≦0.4 wt % Ti, ≦0.5 wt % C, 0.2-0.5 wt % Zr and 0.05-0.1 wt % B and the only specific examples include at least 5 wt % Cr.
Resistance heaters of various materials are disclosed in U.S. Pat. No. 5,249,586 and in U.S. patent application Ser. Nos. 07/943,504, 08/118,665, 08/105,346 and 08/224,848.
U.S. Pat. No. 4,334,923 discloses a cold-rollable oxidation resistant iron-base alloy useful for catalytic converters containing ≦0.05% C, 0.1-2% Si, 2-8% Al, 0.02-1% Y, <0.009% P, <0.006% S and <0.009% O.
U.S. Pat. No. 4,684,505 discloses a heat resistant iron-base alloy containing 10-22% Al, 2-12% Ti, 2-12% Mo, 0.1-1.2% Hf, ≦1.5% Si, ≦0.3% C, ≦0.2% B, ≦1.0% Ta, ≦0.5% W, ≦0.5% V, ≦0.5% Mn, ≦0.3% Co, ≦0.3% Nb, and ≦0.2% La.
Japanese Laid-open Patent Application No. 53-119721 discloses a wear resistant, high magnetic permeability alloy having good workability and containing 1.5-17% Al, 0.2-15% Cr and 0.01-8% total of optional additions of <4% Si, <8% Mo, <8% W, <8% Ti, <8% Ge, <8% Cu, <8% V, <8% Mn, <8% Nb, <8% Ta, <8% Ni, <8% Co, <3% Sn, <3% Sb, <3% Be, <3% Hf, <3% Zr, <0.5% Pb, and <3% rare earth metal.
A 1990 publication in Advances in Powder Metallurgy, Vol. 2, by J. R. Knibloe et al., entitled “Microstructure And Mechanical Properties of P/M Fe
3
Al Alloys”, pp. 219-231, discloses a powder metallurgical process for preparing Fe
3
Al containing 2 and 5% Cr by using an inert gas atomizer. To make sheet, the powders were canned in mild steel, evacuated and hot extruded at 1000° C. to an area reduction ratio of 9:1. After removing from the steel can, the alloy extrusion was hot forged at 1000° C. to 0.340 inch thick, rolled at 800° C. to sheet approximately 0.10 inch thick and finish rolled at 650° C. to 0.030 inch.
A 1991 publication in Mat. Res. Soc. Symp. Proc., Vol. 213, by V. K. Sikka entitled “Powder Processing of Fe
3
Al-Based Iron-Aluminide Alloys,” pp. 901-906, discloses a process of preparing 2 and 5% Cr containing Fe
3
Al-based iron-aluminide powders fabricated into sheet. To make sheet, the powders were canned in mild steel and hot extruded at 1000° C. to an area reduction ratio of 9:1. The steel can was removed and the bars were forged 50% at 1000° C., rolled 50% at 850° C. and finish rolled 50% at650° C. to 0.76 mm sheet.
A paper by V. K. Sikka et al., entitled “Powder Production, Processing, and Properties of Fe
3
Al”, pp. 1-11, presented at the 1990 Powder Metallurgy Conference Exhibition in Pittsburgh, Pa., discloses a process of preparing Fe
3
Al powder by melting constituent metals under a protective atmosphere, passing the metal through a metering nozzle and disintegrating the melt by impingement of the melt stream with nitrogen atomizing gas. An extruded bar was produced by filling a 76 mm mild steel can with the powder, evacuating the can, heating 1½ hour at 1000° C. and extruding the can through a 25 mm die for a 9:1 reduction. A sheet 0.76 mm thick was produced by removing the can, forging 50% at 1000° C., rolling 50% at 850° C. and finish rolling 50% at 650° C.
Oxide dispersion strengthened iron-base alloy powders are disclosed in U.S. Pat. Nos. 4,391,634 and 5,032,190. The '634 patent discloses Ti-free alloys containing 10-40% Cr, 1-10% Al and ≦10% oxide dispersoid. The '190 patent discloses a method of forming sheet from alloy MA 956 having 75% Fe, 20% Cr, 4.5% Al, 0.5% Ti and 0.5% Y
2
O
3
.
A publication by A. LeFort et al., entitled “Mechanical Behavior of FeAl
40
Intermetallic Alloys” presented at the Proceedings of International Symposium on Intermetallic Compounds—Structure and Mechanical Properties (JIMIS-6), pp. 579-583, held in Sendai, Japan on Jun. 17-20, 1991, discloses various properties of FeAl alloys (25 wt % Al) with additions of boron, zirconium, chromium and cerium. The alloys were prepared by vacuum casting and extruding at 1100° C. or formed by compression at 1000° C. and 1100° C.
A publication by D. Pocci et al., entitled “Production and Properties of CSM FeAl Intermetallic Alloys” presented at the Minerals, Metals and Materials Society Conference (1994 TMS Conference) on “Processing, Properties and Applications of Iron Aluminides”, pp. 19-30, held in San Francisco, Calif. on Feb. 27-Mar. 3, 1994, discloses various properties of Fe
40
Al intermetallic compounds processed by different techniques such as casting and extrusion, gas atomization of powder and extrusion and mechanical alloying of powder and extrusion and that mechanical alloying has been employed to reinforce the material with a fine oxide dispersion. The article states that FeAl alloys were prepared having a B2 ordered crystal structure, an Al content ranging from 23 to 25 wt % (about 40 at %) and alloying additions of Zr, Cr, Ce, C, B and Y
2
O
3
.
A publication by J. H. Schneibel entitled “Selected Properties of Iron Aluminides”, pp. 329-341, presented at the 1994 TMS Conference discloses properties of iron aluminides. This article reports properties such as melting temperatures, electrical resistivity, thermal conductivity, thermal expansion and mechanical properties of various FeAl compositions.
A publication by J. Baker entitled “Flow and Fracture of FeAl”, pp. 101-115, presented at the 1994 TMS Conference discloses an overview of the flow and fracture of the B2 compound FeAl. This article states that prior heat treatments strongly affect the mechanical properties of FeAl and that higher cooling rates after elevated temperature annealing provide higher room temperature yield strength and hardness but lower ductility due to excess vacancies.
A publication by D. J. Alexander entitled “Impact Behavior of FeAl Alloy FA-350”, pp. 193-202, presented at the 1994 TMS Conference discloses impact and tensile properties of iron aluminide alloy FA-350. The FA-350 alloy includes, in atomic %, 35.8% Al, 0.2% Mo, 0.05% Zr and 0.13% C.
A publication by C. H. Kong entitled “The Effect of Ternary Additions on the Vac
Hajaligol Mohammad R.
Sikka Vinod K.
Burns Doane , Swecker, Mathis LLP
Chrysalis Technologies Incorporated
Mai Ngoclan
LandOfFree
Method of manufacturing metallic products such as sheet by... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing metallic products such as sheet by..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing metallic products such as sheet by... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497419