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Iron & steel
Literature
Review~~~~~~~~~~~!!!!!!!!
presented at TMS/AIMF Fall Indianapolis. October 2-5. 1989.
Meeting.
Mechanical alloying is a solid state processing procedure whereby elemental or master alloy feedstocks are mechanically combined in a fracturing/cold welding process in order to produce composite alloys. As a consequence of the MA process, a fine grained microstructure is developed with various intermetallic phases and oxide and carbide dispersoids. This paper examines the microstructures developed in MA AI with "and without transition metal addition. MECHANICAL ALLOYING ANDREACTION MILLING OF DISPERSION STRENGTIIENED Al MATERIALS AND SUPERALLOYS H Denninger,ot al, (Univ.ofVienna. Inst. forChern. Techn. of Inorganic Materials).Paper presented at TMS/AIMF Fall Meeting. Indianapolis, October 2-5,1989. This paper describes the results of fundamental investigations into the behaviour of different metal powders and powder mixtures during high energy milling. The influence of added dispersoids, milling agents, on the milling atmosphere and the energy introduced are described. The paper discusses the correlations between various measures applied during the different stages of material production and the resulting properties.
intermetallic). These alloys possess very good mechanical strength at both room and elevated temperatures due not only to the Al-transitionmetal intermetallic phase. but also because of the oxide and carbide dispersion of particles introduced into the microstructure fromthe MAprocess.This paper reviews the tensile, creep and creep rupture, fracture toughness. and fatigue and fatigue crack growth properties of mechanically alloyed Al base materials and assess their suitability for use at elevated temperatures.
Copper MICROSTRUCTURE AND MECHANICAL PROPERTIES OF CU·15wt%Ni·8wt%Sn ALLOY PROCESSED BYTHE OSPREY PROCESS RH Cookey.] VWood (OpenUniv., Milton Keynes. UK). Paper presented at the 1989 Powder Metallurgy Group Meeting. 9·11 October 1989. Bowncss-on-Wlndermere. The effects of Osprey processing on the performance of Cu-15wt%Ni·8\\1%Sn has been investigated in terms of microstructure and mechanical properties.
EFFECTS OF PROCESSING ADDITIVES DURING TIlE MECHANICAL ALLOYING OF Al
AIalloys produced frompowders manufactured by solid state milling processes. such as mechanical alloying, have unique combinations of properties. The structure of these materials is characterized by fine grains and finely distributed oxide and carbide particles. The originof this structure, and thus alloy properties. can be traced to the mechanical alloying process and the resultant powder characteristics. Due to the characteristics of aluminum. processing additives arc normally used to prevent excessive agglomeration of the powder during milling. These additives can be solids. liquids, or gases.The effects ofadditives on the milling processsand subsequent processing and properties are discussed.
A REVIEW OF TIlE MECHANICAL PROPERTIES OF DISPERSION STRENGTHENED MECHANICAU.Y ALLOYED AI FOR ELEVATED TEMPERATURE APPLICATIONS
JA Hawk. ct al, (Dept. of Mats,Science, Univ. of Va.• Charlollesville. USA). Paper presented at TMS/AIMF Fall Meeting. Indianapolis. October _2-5, 1989. Mechanical alloying has provided a means of producing AI alloys with high volume fractions of thermally stable Al-transition metal intcrmetalllc phases (e.g. , alloying with Ti gives an AIJTi
MPR January 1990
MJ Nash (GKN Bound BrookLtd).Paper presented at the 1989PowderMetallurgyGroup Meeting.9-11 October 1989. Bowness-on-Windermere. Over a number of years many processes have been utilised for protectingsintered Fe parts in corrosive environments. These were usually taken from the solid steel treatment and applied to sinlerings with varying degrees of success. Over the last few years several processes have been developed that can be applied to sintering. Their effectiveness and the necessary precautions to make them effective have been examined. SURFACE INTEGRITY OF TURNED FERROUS POWDER M~'TALLURGY COMPONENTS GT Smith (SouthamptonInst.of HigherEducation). Paper presented at the 1989 Powder Metallurgy 9-11 October 1989. Group Meeting. Bowncss-on-Windermere. A review of the surface texture produced by secondary machining PMcomponents is presented along with suggestions for improving the finish. MICROSTRUCTURE AND PROPERTIES OF HARDENED PHOSPHORUS ALLOYED SINTERED STEELS
Injection Moulding
] H Weber (lncoMAP Ligh Alloys. Inco Alloys International, Huntington, WV. USA). Paper presented at TMS/AIMF Fall Meeting, Indianapolis, October 2-5, 1989.
SURFACE TREATMENTS FORTIlE CORROSION PROTECTION OF SINTERED Fe-PARTS
EXTRACTION DEBINDING OF INJECTION MOULDED PARTSBYCONDENSED SOLVENT S T Lin. R MGerman,(RensselaerPolytechnic Inst., Troy, NY, USA). Powder Metallurgy International, No 5. 1989. 19-24. A brief review of the various methods of debinding injection moulded parts is followed by details of a process termed extraction debinding by condensed solvent.
Iron & Steel
P Engdahl. et al, (Hiiganas. Sweden). Paper presented at the 1989 Powder Metallurgy Group Meeting, 9·11 October 1989. Bowness-onWindermere. Results are presented concerning the impactenergy. hardness and microstructure of hardened and case-hardened phosphorus-alloyed sintered steels. Possible causes of the embrittlernent associated with these materials are discussed. CHARACTERIZATION OF FINEPRECIPITATES IN MICROALLOYED STEELS ] R Michael (Bethlehem ' Steel Corporation, Bethlehem, pA. USA). Paper presented at TMS/AIMF Fall Meeting. Indianapolis. October 2-5, 1989.
EFFECT OF C UPONTHE DIMENSIONAL AND MICROSTRUCTURAL CHARACTERISTICS OF Fe-CuCOMPACTS DURING SINTERING
The techniques associated with microanalysis of small precipitates and experimental results of precipitate chemistries and their influence on steel properties are"discussed.
R L Lawcock, T J Davies (GKN Technology Ltd). Paper presented at the 1989 Powder Metallurgy Group Meeting. 9·11 October 1989. Bowness-on-Winderrnere.
PROCESSING CONDITION OF OXIDE DISPERSION STRENGTHENED FERRITIC STEEL BYMECHANICAL ALLOYING
The work presented here confirms the dihedral angle effects reported by Chadwick et al and the dilatometry studies ofDautzenbergand Dorwcillcr. New explanations arc offered concerning the reasons for maximum growth at 8\\1% Cu and for the effectof increased shrinkage during isothermal sintering with increasing carbon content. It is also shown that the interaction of C with the solid state diffusion of Cu in Fe plays an important role in the boundary penetration phenomenon.
T Okuda, et al, (PowderReactor&NuclearFuel Dov. Corp.). Paper presented at TMS/AIMFFall Meeting. Indianapolis. October 2-5. 1989. An effort is underway to develop oxide dispersion strengthened ferritic steels as a candidate core materialforlargescale FBR's. Manyfactorsaffecting high strengthening were investigated in the mechanical alloying and following extrusion process for 12Cr-'1'203 base ferritic steels.
67
~~~~~~~~~~~~Literature SYNERGISTIC EFFECTS OF Si AND ON SINTERING OF FERROUS METAL POWDER COMPACTS
x Qu, et al, Canadian Metollurgicol Quarter/y. Vol. 28, No.4. 1989, 345-352. The sintering and alloying behaviour of ferrous metal powder compacts has been studied using dilatometry and scanning electron microscopy. Twobinary compositions. Fe-3\\1 % Si and Fe-3wt % FeJP (0.46wt % Pl. and one ternary. Fe-3 wt % Si-3 wt % FeJP were compared.
TEMPERATURE INFLUENCE OF REDUCTION ANNEALING ON OXYGEN CONTENT IN SINTERED COMPACTS FROMPRE-ALLOYING WATER-ATOMIZED Fe-1Cr-0.7 Mn-0.2MoSTEEL POWDER . V Vrabel. Prokroky Ptaskove Meta/urgie•. No.2. 1989.57-71. This paper deals with problems related to reduction of complex oxides Fe-Cr-Mn in prealloycd water atomized Fe-1Cr-0.7Mn-O.2Mo powder steel during reduction annealing and sintering. Influence ofreduclion annealing temperature on oxygen content in powder after annealing and influence of starting oxygen content in compacts on final oxygen content in compacts after sintering were studied. By otpimising annealing and sintering parameters combination the mean oxygen content in sintercd compacts was reduced to a value of 0.05 mass %.
High Alloy Tool Steels
Titanium METASTABLE PHASE FORMATION IN RAPIDLY-SOLIDIFIED TiAI E L Hall. S CHuang.' (GE Corp. Res. and Dev.• Schenectady. NY, USA). Paper presented at TMSfAIMF Fall Meeting. Indianapolis, October 2-5, 1989. Ti-AI binary alloys containing from 46 to 70 at. % AIwere rapidly solidified by meltspinning, and the microstructures of these melt-spun ribbons studied usins analytical electron microscopy. Comparison ofth~ results with conventionally-processed ingots of the same alloys and with the equilibrium phase diagram .showed that metastable microstructures had formed in each of the ribbons. The microstructures of each of the ribbons arc described in detail. and the results rationalised with regard to metastable extensions of the equilibrium phase diagram.
M Igharo, J V Wood (Open University). Paper presented at the 1989 Powder Metallurgy Group Meeting, 9-11 October 1989. Bowness-onWindermere. A review paper of the effects of consolidation parameterson the properties of sintered high speed steels.
PHYSICAL METALLURGY OF I1IGII TEMPERATURE INTERMETALLlC·BASED ALLOYS BYMECHANICAL ALLOYING R C Bonn, et al, (Inca Alloys. International. Huntington. WV. USA). Paper presented at TMSfAIMF Fall Meeting, Indianapolis. October 2-5: 1989.
Bowness-on-Windermere.
The ability to make alloys via solid state processing from normally incompatible components is one of the attractions of mechanical alloying (MA). There is considerable interest in the development of intermetallic systems such as aluminides for, inter alia, improved density-compensated streng~h properties, oxidation resistance, and low strategic clement content. This paper reports on the structural development of selected intermetallic systems synthesized by mechanical alloying. Systems based on Ni, Ti. Nb, and Al will be described. and the implications and potential usc of some unique microstructures discussed.
This paper reports on work undertaken to evaluate the process of mechanical alloying for sintered steels with a dispersed in-soluble hard phase and to optimize the processing parameters.
SHOCK CONSOLIDATION OF Ti ALUMINIDE POWDERS A Ferreira.et aI,(Univ.ofCalifornia,San Diego. CA.
MECHANICALLY ALLOYED SINTERED STEELS WITHI1IGII CARBIDE CONTENT C Cutsfeld, (University and Nuclear Research Centre. Karlsruhe. West Germany.) Paper presented at the 1989 Powder Metallurgy Group 9-11 October. 1989. Meeting.
68
USA). Paper presented at TMSfAIMF Fall Meeting, Indianapolis, October 2-5.1989. R-STi-aluminido powders with base compositions Ti-14wt%AI- 21\\1%Nb(FCT) and Ti(30-33]\\1%AI (14-20)\\1%Nb (BCC) were shock consolidated usins explosives in a cylindrical geometry with a flyerO tube. SEM. TEM and mechanical testing results are reported along with the processing conditions. MA, CHARACTERIZATION AND CONSOLIDATION OF Ti ANDNi ALUMINIDES P Nash. et al (Departmentof Metallurgicaland Mat. Eng.• Illinois. Institute of Technology. Chicago. II. USA). Paper presented at TMSfAIMF Fall Meeting, Indianapolis, October 2-5. 1989.
Mechanical alloying is being investigated as a processing route for the production of aluminide intermetallics. This programme involves powder production and characterization,consolidation and thermal treatments and determination of microstructure-property relationships. An attritor STRUCTURE AND MECHANICAL PROPERTIES mill is beinz used to produce powder and the OF TiAl COMPACT PRODUCED BYHOT processing parameters are being systematically PRESSING OF MECHANICALLY ALLOYED varied to establish the optimum milling conditions. POWDER Powder is being characterized using thermal analysis, optical and electron microscopyand x-ray H Suzimoto, et al, (Ritsumeikan Univ., Kyoto). j. diffraction. Consolidation of the powder is being japa::Inst. Metals. Vol.53. No 6.1989,628-634, in" approached in several different ways including Japanese). cold isostatic pressing, sintcring, extrusion and hot pressing. The results of the program so far are The mixture of elemental powders ofTi {64 mass% presented and future directions discussed. (50 at%)) and Al (36 mass% (50 at%)) was offered to a mechanical alloying process. The processed powder was vacuum hot pressed at 1173 K for 3.6 REACTION SINTERING·HOT PRESSED TiAI ks under 100 MPa. the produced compact having relative density of 99.8%. J C Rawers, et al. (Albany. OR. USA). Paper presented at. TMSfAIMF Fall Meeting. Indianapolis, October 2-5. 1989.
Ceramics EFFECTS OF CONSOLIDATION PARAMETERS ON THEPROPERTIES OF SINTERED I1IGII SPEED STEELS
Review
Ti aluminide intermetallic alloys and composites were formed from elemental powders by reaction sintering in a hot press. The principal phase formed was TiAI with a significant second-phase concentration of TiJAI. Physical properties (phases formed and density) and mechanical properties (transverse rupture stress and hardness) of the reaction sintered compacts were investigated. FABRICATION AND PROPERTIES OF PM TITANIUM ALUMINIDES K Shibue, S Yamauchi (Sumitomo Light Metal Industries, Ltd,Chitose,Minato-ku,Nagoya. Japan). Paper presented at TMSfAIMF Fall Meeting, Indianapolis, October 2-5.1989. The purpose of this work was to fabricate fully dense PM TiAI by means of the reactive sintering process. Relativedensity of PM TiAI was obtained over 97%, and the tensile strength of PM TiAI was equivalent to that of 1M TiAI. Titanium and aluminum powders were prepared. and roactlvc-sintering using a vacuum furnace of hot isostatic pressing. Materials produced by .the reactive sintering were characterized by optical metallography, scanning electron microscopy. X-ray and thermal analyses and mechanical properties.
MPR January 1990
Review~~~~~~~~~~~!!!!!!!!
presented at TMS/AIMF Fall Indianapolis. October 2-5. 1989.
Meeting.
Mechanical alloying is a solid state processing procedure whereby elemental or master alloy feedstocks are mechanically combined in a fracturing/cold welding process in order to produce composite alloys. As a consequence of the MA process, a fine grained microstructure is developed with various intermetallic phases and oxide and carbide dispersoids. This paper examines the microstructures developed in MA AI with "and without transition metal addition. MECHANICAL ALLOYING ANDREACTION MILLING OF DISPERSION STRENGTIIENED Al MATERIALS AND SUPERALLOYS H Denninger,ot al, (Univ.ofVienna. Inst. forChern. Techn. of Inorganic Materials).Paper presented at TMS/AIMF Fall Meeting. Indianapolis, October 2-5,1989. This paper describes the results of fundamental investigations into the behaviour of different metal powders and powder mixtures during high energy milling. The influence of added dispersoids, milling agents, on the milling atmosphere and the energy introduced are described. The paper discusses the correlations between various measures applied during the different stages of material production and the resulting properties.
intermetallic). These alloys possess very good mechanical strength at both room and elevated temperatures due not only to the Al-transitionmetal intermetallic phase. but also because of the oxide and carbide dispersion of particles introduced into the microstructure fromthe MAprocess.This paper reviews the tensile, creep and creep rupture, fracture toughness. and fatigue and fatigue crack growth properties of mechanically alloyed Al base materials and assess their suitability for use at elevated temperatures.
Copper MICROSTRUCTURE AND MECHANICAL PROPERTIES OF CU·15wt%Ni·8wt%Sn ALLOY PROCESSED BYTHE OSPREY PROCESS RH Cookey.] VWood (OpenUniv., Milton Keynes. UK). Paper presented at the 1989 Powder Metallurgy Group Meeting. 9·11 October 1989. Bowncss-on-Wlndermere. The effects of Osprey processing on the performance of Cu-15wt%Ni·8\\1%Sn has been investigated in terms of microstructure and mechanical properties.
EFFECTS OF PROCESSING ADDITIVES DURING TIlE MECHANICAL ALLOYING OF Al
AIalloys produced frompowders manufactured by solid state milling processes. such as mechanical alloying, have unique combinations of properties. The structure of these materials is characterized by fine grains and finely distributed oxide and carbide particles. The originof this structure, and thus alloy properties. can be traced to the mechanical alloying process and the resultant powder characteristics. Due to the characteristics of aluminum. processing additives arc normally used to prevent excessive agglomeration of the powder during milling. These additives can be solids. liquids, or gases.The effects ofadditives on the milling processsand subsequent processing and properties are discussed.
A REVIEW OF TIlE MECHANICAL PROPERTIES OF DISPERSION STRENGTHENED MECHANICAU.Y ALLOYED AI FOR ELEVATED TEMPERATURE APPLICATIONS
JA Hawk. ct al, (Dept. of Mats,Science, Univ. of Va.• Charlollesville. USA). Paper presented at TMS/AIMF Fall Meeting. Indianapolis. October _2-5, 1989. Mechanical alloying has provided a means of producing AI alloys with high volume fractions of thermally stable Al-transition metal intcrmetalllc phases (e.g. , alloying with Ti gives an AIJTi
MPR January 1990
MJ Nash (GKN Bound BrookLtd).Paper presented at the 1989PowderMetallurgyGroup Meeting.9-11 October 1989. Bowness-on-Windermere. Over a number of years many processes have been utilised for protectingsintered Fe parts in corrosive environments. These were usually taken from the solid steel treatment and applied to sinlerings with varying degrees of success. Over the last few years several processes have been developed that can be applied to sintering. Their effectiveness and the necessary precautions to make them effective have been examined. SURFACE INTEGRITY OF TURNED FERROUS POWDER M~'TALLURGY COMPONENTS GT Smith (SouthamptonInst.of HigherEducation). Paper presented at the 1989 Powder Metallurgy 9-11 October 1989. Group Meeting. Bowncss-on-Windermere. A review of the surface texture produced by secondary machining PMcomponents is presented along with suggestions for improving the finish. MICROSTRUCTURE AND PROPERTIES OF HARDENED PHOSPHORUS ALLOYED SINTERED STEELS
Injection Moulding
] H Weber (lncoMAP Ligh Alloys. Inco Alloys International, Huntington, WV. USA). Paper presented at TMS/AIMF Fall Meeting, Indianapolis, October 2-5, 1989.
SURFACE TREATMENTS FORTIlE CORROSION PROTECTION OF SINTERED Fe-PARTS
EXTRACTION DEBINDING OF INJECTION MOULDED PARTSBYCONDENSED SOLVENT S T Lin. R MGerman,(RensselaerPolytechnic Inst., Troy, NY, USA). Powder Metallurgy International, No 5. 1989. 19-24. A brief review of the various methods of debinding injection moulded parts is followed by details of a process termed extraction debinding by condensed solvent.
Iron & Steel
P Engdahl. et al, (Hiiganas. Sweden). Paper presented at the 1989 Powder Metallurgy Group Meeting, 9·11 October 1989. Bowness-onWindermere. Results are presented concerning the impactenergy. hardness and microstructure of hardened and case-hardened phosphorus-alloyed sintered steels. Possible causes of the embrittlernent associated with these materials are discussed. CHARACTERIZATION OF FINEPRECIPITATES IN MICROALLOYED STEELS ] R Michael (Bethlehem ' Steel Corporation, Bethlehem, pA. USA). Paper presented at TMS/AIMF Fall Meeting. Indianapolis. October 2-5, 1989.
EFFECT OF C UPONTHE DIMENSIONAL AND MICROSTRUCTURAL CHARACTERISTICS OF Fe-CuCOMPACTS DURING SINTERING
The techniques associated with microanalysis of small precipitates and experimental results of precipitate chemistries and their influence on steel properties are"discussed.
R L Lawcock, T J Davies (GKN Technology Ltd). Paper presented at the 1989 Powder Metallurgy Group Meeting. 9·11 October 1989. Bowness-on-Winderrnere.
PROCESSING CONDITION OF OXIDE DISPERSION STRENGTHENED FERRITIC STEEL BYMECHANICAL ALLOYING
The work presented here confirms the dihedral angle effects reported by Chadwick et al and the dilatometry studies ofDautzenbergand Dorwcillcr. New explanations arc offered concerning the reasons for maximum growth at 8\\1% Cu and for the effectof increased shrinkage during isothermal sintering with increasing carbon content. It is also shown that the interaction of C with the solid state diffusion of Cu in Fe plays an important role in the boundary penetration phenomenon.
T Okuda, et al, (PowderReactor&NuclearFuel Dov. Corp.). Paper presented at TMS/AIMFFall Meeting. Indianapolis. October 2-5. 1989. An effort is underway to develop oxide dispersion strengthened ferritic steels as a candidate core materialforlargescale FBR's. Manyfactorsaffecting high strengthening were investigated in the mechanical alloying and following extrusion process for 12Cr-'1'203 base ferritic steels.
67
~~~~~~~~~~~~Literature SYNERGISTIC EFFECTS OF Si AND ON SINTERING OF FERROUS METAL POWDER COMPACTS
x Qu, et al, Canadian Metollurgicol Quarter/y. Vol. 28, No.4. 1989, 345-352. The sintering and alloying behaviour of ferrous metal powder compacts has been studied using dilatometry and scanning electron microscopy. Twobinary compositions. Fe-3\\1 % Si and Fe-3wt % FeJP (0.46wt % Pl. and one ternary. Fe-3 wt % Si-3 wt % FeJP were compared.
TEMPERATURE INFLUENCE OF REDUCTION ANNEALING ON OXYGEN CONTENT IN SINTERED COMPACTS FROMPRE-ALLOYING WATER-ATOMIZED Fe-1Cr-0.7 Mn-0.2MoSTEEL POWDER . V Vrabel. Prokroky Ptaskove Meta/urgie•. No.2. 1989.57-71. This paper deals with problems related to reduction of complex oxides Fe-Cr-Mn in prealloycd water atomized Fe-1Cr-0.7Mn-O.2Mo powder steel during reduction annealing and sintering. Influence ofreduclion annealing temperature on oxygen content in powder after annealing and influence of starting oxygen content in compacts on final oxygen content in compacts after sintering were studied. By otpimising annealing and sintering parameters combination the mean oxygen content in sintercd compacts was reduced to a value of 0.05 mass %.
High Alloy Tool Steels
Titanium METASTABLE PHASE FORMATION IN RAPIDLY-SOLIDIFIED TiAI E L Hall. S CHuang.' (GE Corp. Res. and Dev.• Schenectady. NY, USA). Paper presented at TMSfAIMF Fall Meeting. Indianapolis, October 2-5, 1989. Ti-AI binary alloys containing from 46 to 70 at. % AIwere rapidly solidified by meltspinning, and the microstructures of these melt-spun ribbons studied usins analytical electron microscopy. Comparison ofth~ results with conventionally-processed ingots of the same alloys and with the equilibrium phase diagram .showed that metastable microstructures had formed in each of the ribbons. The microstructures of each of the ribbons arc described in detail. and the results rationalised with regard to metastable extensions of the equilibrium phase diagram.
M Igharo, J V Wood (Open University). Paper presented at the 1989 Powder Metallurgy Group Meeting, 9-11 October 1989. Bowness-onWindermere. A review paper of the effects of consolidation parameterson the properties of sintered high speed steels.
PHYSICAL METALLURGY OF I1IGII TEMPERATURE INTERMETALLlC·BASED ALLOYS BYMECHANICAL ALLOYING R C Bonn, et al, (Inca Alloys. International. Huntington. WV. USA). Paper presented at TMSfAIMF Fall Meeting, Indianapolis. October 2-5: 1989.
Bowness-on-Windermere.
The ability to make alloys via solid state processing from normally incompatible components is one of the attractions of mechanical alloying (MA). There is considerable interest in the development of intermetallic systems such as aluminides for, inter alia, improved density-compensated streng~h properties, oxidation resistance, and low strategic clement content. This paper reports on the structural development of selected intermetallic systems synthesized by mechanical alloying. Systems based on Ni, Ti. Nb, and Al will be described. and the implications and potential usc of some unique microstructures discussed.
This paper reports on work undertaken to evaluate the process of mechanical alloying for sintered steels with a dispersed in-soluble hard phase and to optimize the processing parameters.
SHOCK CONSOLIDATION OF Ti ALUMINIDE POWDERS A Ferreira.et aI,(Univ.ofCalifornia,San Diego. CA.
MECHANICALLY ALLOYED SINTERED STEELS WITHI1IGII CARBIDE CONTENT C Cutsfeld, (University and Nuclear Research Centre. Karlsruhe. West Germany.) Paper presented at the 1989 Powder Metallurgy Group 9-11 October. 1989. Meeting.
68
USA). Paper presented at TMSfAIMF Fall Meeting, Indianapolis, October 2-5.1989. R-STi-aluminido powders with base compositions Ti-14wt%AI- 21\\1%Nb(FCT) and Ti(30-33]\\1%AI (14-20)\\1%Nb (BCC) were shock consolidated usins explosives in a cylindrical geometry with a flyerO tube. SEM. TEM and mechanical testing results are reported along with the processing conditions. MA, CHARACTERIZATION AND CONSOLIDATION OF Ti ANDNi ALUMINIDES P Nash. et al (Departmentof Metallurgicaland Mat. Eng.• Illinois. Institute of Technology. Chicago. II. USA). Paper presented at TMSfAIMF Fall Meeting, Indianapolis, October 2-5. 1989.
Mechanical alloying is being investigated as a processing route for the production of aluminide intermetallics. This programme involves powder production and characterization,consolidation and thermal treatments and determination of microstructure-property relationships. An attritor STRUCTURE AND MECHANICAL PROPERTIES mill is beinz used to produce powder and the OF TiAl COMPACT PRODUCED BYHOT processing parameters are being systematically PRESSING OF MECHANICALLY ALLOYED varied to establish the optimum milling conditions. POWDER Powder is being characterized using thermal analysis, optical and electron microscopyand x-ray H Suzimoto, et al, (Ritsumeikan Univ., Kyoto). j. diffraction. Consolidation of the powder is being japa::Inst. Metals. Vol.53. No 6.1989,628-634, in" approached in several different ways including Japanese). cold isostatic pressing, sintcring, extrusion and hot pressing. The results of the program so far are The mixture of elemental powders ofTi {64 mass% presented and future directions discussed. (50 at%)) and Al (36 mass% (50 at%)) was offered to a mechanical alloying process. The processed powder was vacuum hot pressed at 1173 K for 3.6 REACTION SINTERING·HOT PRESSED TiAI ks under 100 MPa. the produced compact having relative density of 99.8%. J C Rawers, et al. (Albany. OR. USA). Paper presented at. TMSfAIMF Fall Meeting. Indianapolis, October 2-5. 1989.
Ceramics EFFECTS OF CONSOLIDATION PARAMETERS ON THEPROPERTIES OF SINTERED I1IGII SPEED STEELS
Review
Ti aluminide intermetallic alloys and composites were formed from elemental powders by reaction sintering in a hot press. The principal phase formed was TiAI with a significant second-phase concentration of TiJAI. Physical properties (phases formed and density) and mechanical properties (transverse rupture stress and hardness) of the reaction sintered compacts were investigated. FABRICATION AND PROPERTIES OF PM TITANIUM ALUMINIDES K Shibue, S Yamauchi (Sumitomo Light Metal Industries, Ltd,Chitose,Minato-ku,Nagoya. Japan). Paper presented at TMSfAIMF Fall Meeting, Indianapolis, October 2-5.1989. The purpose of this work was to fabricate fully dense PM TiAI by means of the reactive sintering process. Relativedensity of PM TiAI was obtained over 97%, and the tensile strength of PM TiAI was equivalent to that of 1M TiAI. Titanium and aluminum powders were prepared. and roactlvc-sintering using a vacuum furnace of hot isostatic pressing. Materials produced by .the reactive sintering were characterized by optical metallography, scanning electron microscopy. X-ray and thermal analyses and mechanical properties.
MPR January 1990