(1975). (b) The grain coarsening associated with secondary recrystallisation process is very rapid. Once above the recrystallisation temperature, it may take only 5 minutes for complete secondary recrystallisation (Cairns et aI.,
(1982). (h) Prestraining can suppress the grain growth during secondary recrystallisation (Singer & Gessinger,
0.8 mm/min, mean RV 496 c. 3.2 mm/min, mean RV 517 e. 7.7 mm/min, mean RV 527 b. 1.4 mm/m in, mean RV 499 d. 5.0 mm/min,
1.4 mm/min, RV 508 b. 3.2 mm/min, RV 523 c. 5.0 mm/min, RV 533 1.5mm L-.-..J Figure 5.14. The microstructure recorded after zone annealing (at Tp = 1300 0c) specimens in a direction perpendicular to the rolling direction.
(1970). 105The grain structure of dispersion strengthened Ni-base alloys produced by mechanical alloying is generally characterised by coarse, elongated grains (Benjamin,
151Table 7.3. Hardness (HVN) data obtained after isothermal annealing of MA957 at different temperatures and for a variety of time periods.
187Table 9.2a. Hardness data obtained for aluminium alloy AI-5 after isothermally annealing at 400, 450, 500 and 550°C, for the time periods ranging from 900 to 3687200 seconds.
188Table 9.2b. Hardness data obtained for aluminium alloy AI-IS after isothermally annealing at 200,250,300 and 350 DC, for the time periods ranging from 900 to 3687200 seconds.
189Table 9.2b. Hardness data obtained for aluminium alloy AI-I5 after isothermally annealing at 400,450,500 and 550 DC, for the time periods ranging from 900 to 3687200 seconds.
2.2~ ·;"12 . 'I I ....... ~ ,'''
208Figure 10.3 Optical micrographs showing the equiaxed grain structure observed after zone annealing alloy AA3003 at 430°C with following specimen travel speeds (mm/min):
(1973). 223Table 12.1. Thermochemical properties of K2S04, after Brain and Knacke
224Symbols and abbreviations used in the Table 12.1.
(2000). 4.2E-l1 C i= 1.5E-1I i= b '" '" "- "- a a 3.2E-1I I i ~ 1.0E-1t ~ ~ 2.0(-11 5.2£-12 1.2(-11 2.2[·aa 2.2=:·33 S" le03 151'0 2023 2523 J223 52. 1000 IS"
(1986). 5.2 Alloy production Nickel base aDS alloys are produced by an advanced powder metallurgy route called mechanical alloying (Reetwood,
5.2. Temperatures recorded at three positions on the same sample during zone annealing at Tp = lI50°C. Note that the travel time through the R. F. coil increases with the row number in each tabulation.
6.2c. Microstructure and Vickers hardness data obtained for Inconel alloy MA956, after zone annealing at 1380 QCwith different specimen travel speeds.
(1963). 6.3 Microstructure of ODS Fe-er-AI Alloys Secondary recrystallisation (Aust,
(1977). a /' 6 •• LONG.- 2000°F - TRANS.
(1980). According to Hotzler and Glasgow
(1983). ASM, Metals Congress,
b a c c 4.2E-15 4.e::-15 e d b ;::: 3.e~-15 d ;::: 3.0::-15 c:: c:: e "- "- a 0 f I I ~
C.(1970), Differential Thermal Analysis, Pbls.
(1963). chapter 23 in "The Art and Science of Growing Crystals",
(1977). ferritic compositions are characterised by lower thermal expansion coefficient than Nibase alloys which should be beneficial to thermal fatigue life (Fischer et al.,
(2000). Figure Tp Profiles Specimen travel speeds mm/min. 7.14iA. 1150°C a - d 0.8, 104,3.2 and 5.0 7.14iB. 7.14iC. a-d a-d 0.8, lA, 3.2 and 5.0 0.8, lA,
(2000). Figure Tp Profiles Specimen travel speeds mm/min. 7.14iiA. 1250°C a - f 0.2, 0.4, 0.8, 1.4, 3.2 and 5.0 7.14iiB. 7.14iiC. a - f a - f 0.2,
Figure Tp Profiles Specimen travel speeds mm/min. 7.15iA. 1150°C a - d 0.8, 1.4, 3.2 and 5.0 7.15iB. 1150°C a-d 0.8, 1.4, 3.2 and 5.0 7.15iC. 1150°C a - d 0.8. 1.4. 3.2 and 5.0 169s.eE:-IS A
Figure Tp Profiles Specimen travel speeds mm/min. 7.15iiiA. 1350°C a - f 0.8, 1.4, 3.2, 5.0, 7.7 and 10.0 7.15iiiB. 1350°C a - f 0.8, 1.4, 3.2, 5.0, 7.7 and 10.0 7.15iiiC. 1350°C a -
(1989). Fracture and Fatigue in MMCs, Dissertation submited for the CPGS.
(1983). Frontiers of high temperature materials lI."
(1987). Graded SiC powder alloy powder ./ ~./ Blending 1 MMC powder 1 Canning J Deg3ssing ! (Consolidation) ! Secondary processing Figure 3.1. Flow sheet diagram illustrating the powder blending route commonly used to produce MMCs (after White et al.
(1983). Graduate Lectures on Thermal Analysis,
Grain Size (G') mm MA6000
(1979). growth results in a characteristic texture (Claudia et al.,
(2000). i ~ i 1000 'i \ ,u ,~ . " \ , : : "0 ;
(1986). in " High Temperature Alloys for Gas Turbines and other Applications."
(1972). in " The Superalloys",
(1983). in "Physical Metallurgy, part 2." 3rd
(1984). in "PM Aerospace Materials", A Metal Powder Report Conf.
(1984). in "Superalloys 1984."
(1972). in "The Superalloys"
(1963). Iron and its Dilute Solid Solutions,
(1984). It is thought that the recrystallisation response of MA6000 is less sensitive to its thermomechanical history than any other aDS nickel base superalloy (Gessinger,
(1981). Me tall.
(1979). Met Sci.
(1983). Metal Reference Book, Sixth Edition,
Micrographs taken after zone annealing MA6000 at Tp = 1100°C. The specimen travel speeds and hardness data are as follows: a.
(1972). of y phase is usually considered to be Ni3(AI-Ti), and is described as a superlattice, possessing CU3Au (L12)-type structure by Stoloff
Optical micrographs taken after isothermally annealing specimens from alloy MA6000 at 1100°C for: a. 900 seconds,
Peak temperature measured at point
(1988). Ph.D. Thesis, University of Cambridge. "The diffusion brazing of 237nickel-based ODS alloys."
(1962). Physical Metallurgy for Engineers,
(1984). Plastic Defonnation of Metals,
(1984). Powder Metallurgy of Superalloys." Butterworths,
(1985). Rapidly Quenched Metals
(1988). rccrystallises at a very similar temperature to the y -free MA754
(1963). Recovery and Recrystallisation of
(1963). Recovery and Recrystallisation of Metals, lnterscience,
(1965). Recovery, Recrystallisation and Grain Growth of Metals,
(1976). Recrystallisation and Grain Growth in Metals,
(1971). Recrystallisation of Metallic Materials,
(2000). seconds Time. seconds 600 o 1000
Showing the microstructure recorded after zone annealing. The specimens were prepared with the zone annealing direction perpendicular to the rolling direction at Tp =
(1980). Since the reference itself is MA6000 (annealed), y effects are absent in this output. Note that the temperature range over which the peaks are observed is consistent with the recrystallisation temperature reported by (Hotzler and Glassgow
(1975). size and grain aspect ratio (GAR) are increased by zone annealing (Cairns et al.,
(1965). Some coincidence site lattice (CSL) relations for cubic crystals, corrected from (Christian,
Temperature (0C) versus time (seconds) profiles, for samples of aDS alloy MA957, which were zone annealed (A) in the as-received condition,
Temperature (0C) versus time (seconds) profiles, for samples of aDS alloy MA957, which were zone annealed (A) in the as-received condition, CB & C) after pre-annealing at 550°C for 90 hours and 10 days respectively, at Tp =
(1978). Texture of Materials",
(1973). The enthalpy (H) for K2S04 at 540 QC is reported in the literature as 2.14 kcaVmol (Brain and Knacke,
(1980). The microstructure of MA6000 before the final recrystallisation heat treatment shows a very fine grained structure of the extruded and hot-rolled material, with an incredibly fine grain size of typically 0.21lm diameter (Hotzler &
(1970). The most highly developed steel, Incoloy alloy MA956 is an oxide dispersion strengthened FeCr-AI alloy produced by the mechanical alloying technique, which is explained in detail by Benjamin
(1980). The observations reported by Hotzler and Glasgow
(1979). The strength properties of this alloy (MA956) are rather similar to the ODS Ni-alloys discussed earlier and it possesses superior high gas velocity oxidation resistance at 1165 K (892°C) when compared with the Ni-base alloys (Whittenberger,
(1972). The Superalloys",
(1965). Theory of Transformations of Metals and Alloys",
(1975). Theory of Transformations of Metals and Alloys", Part I, 2nd ed.
(1984). there is no evidence to support this. MA6000, with 50-55 vol% of y (Gessinger,
(2000). Time. seconds 1400 1300 o~
(2000). Time. seconds Time, seconds 1200 1lOO .u 1000 l'