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Production of PM γtitanium aluminide sheet
of 420 MPa, 13% elongation and fracture toughness of 75 MPa.m’/ were quoted.
and uniaxial compression to calibrate the constitutive equation of the model.
EXTENSION OF SOLID SOLUBILITY OF MAGNESIUM IN TITANIUM BY MECHANICAL ALLOYING
A COMBINATION OF CASTING, FORGING, PM BONDING, AND COATING TO MARE HIGH PERFORMANCE PARTS
F.H.Froes et al. (University of Idaho, Moscow, Idaho, USA. 1 The equilibrium solubility of Mg in Ti is very low. It was reported that MA had been used to process Ti-(5,10,15,20 etc.)wt%Mg. Structure evolution was monitored. About 12%Mg dissolved in the 16,3%Mg alloy compared with 0.7% at 890°C. Nanometre-sized grains were observed in the as-milled powders. Solubility of 0 and N also increased, 0 more than N.
New methods and processes HIP-QUENCHING - A BEAT TRJWTMENT METHOD F.X.Zimmerman, C.Bergman. (ABB Pressure Systems AB, Sweden.) Use of HIP was discussed and it was noted that the slow cooling rates resulted in low productivity. Development of HIP furnaces with faster cooling capaoutlined. In addibility was tion, HIP-quenching was shown to be at up to possible, with cooling 1000”C.min-l.
X.Song et al. (Bindy Co, USA.) A novel manufacturing approach which combines PM with casting, forging, bonding and coating was presented. Flexibility of shape forming, full densification with fine microstructures, powder coating and various bondings are amongst the features. The methods can be used for a range of materials and for single or multiple parts. Some examples were shown with structures and properties. IMPROVEMENTS IN CRYOMILL PROCESSING B.J.M.Aikin, J.J.Juhas. (NASA Lewis Research Centre, USA.) Cryomilling, involving milling at cryogenic temperatures, was used to process Ni aluminide powders in liquid N for up to 12 hours. 1 to 4wt% of N was absorbed by the alloy. Up to 2Ovol%AIN and 2%Al,O, were detected in the alloy. Various problems were outlined with the steps taken against them. Process modifications improved the properties of the cryomilled product, including greater homogeneity.
tored. Mg,Ge was the easiest to form. Synthesis of Mg,Si in metastable and equilibrium states was reported. Phase formation was discussed in terms of thermodynamics. DEVELOPMENT OF A PM PROCESS FOR MAKING NIOBIUM ALUMINIDE SI-IAFES J.H.Moll et al. (Crucible Research, USA.) Investigations aimed at the production of near net shapes in Nb,Al were described. Inert gas atomized powders, ceramic moulds and HIP were used. Special materials were used to allow use of high HIP temperatures. Nb was added to prealloyed powder to improve ductility. Some complex shapes were made. Structures and properties were described.
Composite materials EFFECTS OF HOT FORGING ON STRUCTURE AND PROPERTIES OF ALUMINIUM ALLOY coMFosITEs R.Angers et al. (Lava1 University, Canada.) It was reported that A16061-SiC composites had been hot forged from sintered preforms with the object of establishing the influence of process conditions of structure and properties. The results are held to demonstrate that hot forging of sintered compacts is a viable process route for metal matrix composites.
DEVELOPMENT AND APPLICATION OF RIP TECHNOLOGY
Intermetallic materials
H.Zheng et al. (Central Iron and Steel Research Inst., Beijing, China.) The paper reported on the use of HIP technology for processing a range of ferrous and non-ferrous materials for use in various applications. Equipment capacities and working limits were given as: size 69 by 110 cm, temperature maximum 2000°C and pressure 200 MPa.
PRODUCTION OF PM TITANIUM ALUMINIDE SHEET
DISTRIBUTION OF SILICON CARBIDE IN ALUMINIUM ALLOY COMPOSITE
H.Clemens et al. (Plansee Ag, Reutte, Austria.) The advantages of PM processing for production of yTiA1 over cast/ wrought technology were discussed. It was reported that compacts of Ti-48at%Al-2%Cr and Ti-48%Al-2% Cr-2%Nb had been produced from gas atomized powder and rolled into sheet. The fine grain size and homogeneity of the PM alloys were superior to those made from ingots. Mechanical properties were described.
F.H.Froes et al. (University of Idaho, Moscow, USA.) A comparison of ways of distributing Sic in A12024-5wt%SiC composites, based on experiment, was presented. The methods were ball milling of Al and Sic powders, rapid solidification of Sic flakes and solidification of Al alloy mixed with Sic into ingot. Powder and flake products were compacted and, with the ingot material, were extruded under high energy conditions, solution treated and aged to peak hardness. Distribution of Sic was discussed.
CALIBRATION OF CONSTITUTLVE MODEL FOR HOT ISOSTATIC PRESSING OF BORON POWDER PStutz et al. (University of Grenoble, Grenoble, France.) It was reported that HIP can be used to make net shape parts from B powder but care must be exercised in design of tools and HIP cycle. The need for a model to predict the behaviour of B powder during compaction was noted and a viscoplastic model describing the mechanical behaviour was presented. Experiments were described, using interrupted HIP 44
MPR December
1997
FORMATION OF INTERMETALLIC COMPOUNDS INMAGNESIUMALLOYS DURINGlWECBANICALALLOYING F.H.Froes et al. (University of Idaho, Moscow, Idaho, USA.) It was reported that MA had been used to process Mg-Sn, Mg-Ge and Mg-Si elemental powders. Synthesis of intermetallic compounds was moni-
INNOVATIONS IN PRODUCTION OF AL-ALLOY BABE METAL MATRIX COMPOSITES A.V.Bezroukov, A.I.Litvintsev. (Alspors Technology Ltd, Russia.) It was reported that A12124alloy(15 to 17%)SiC composites had been prepared by a spray deposition
and uniaxial compression to calibrate the constitutive equation of the model.
EXTENSION OF SOLID SOLUBILITY OF MAGNESIUM IN TITANIUM BY MECHANICAL ALLOYING
A COMBINATION OF CASTING, FORGING, PM BONDING, AND COATING TO MARE HIGH PERFORMANCE PARTS
F.H.Froes et al. (University of Idaho, Moscow, Idaho, USA. 1 The equilibrium solubility of Mg in Ti is very low. It was reported that MA had been used to process Ti-(5,10,15,20 etc.)wt%Mg. Structure evolution was monitored. About 12%Mg dissolved in the 16,3%Mg alloy compared with 0.7% at 890°C. Nanometre-sized grains were observed in the as-milled powders. Solubility of 0 and N also increased, 0 more than N.
New methods and processes HIP-QUENCHING - A BEAT TRJWTMENT METHOD F.X.Zimmerman, C.Bergman. (ABB Pressure Systems AB, Sweden.) Use of HIP was discussed and it was noted that the slow cooling rates resulted in low productivity. Development of HIP furnaces with faster cooling capaoutlined. In addibility was tion, HIP-quenching was shown to be at up to possible, with cooling 1000”C.min-l.
X.Song et al. (Bindy Co, USA.) A novel manufacturing approach which combines PM with casting, forging, bonding and coating was presented. Flexibility of shape forming, full densification with fine microstructures, powder coating and various bondings are amongst the features. The methods can be used for a range of materials and for single or multiple parts. Some examples were shown with structures and properties. IMPROVEMENTS IN CRYOMILL PROCESSING B.J.M.Aikin, J.J.Juhas. (NASA Lewis Research Centre, USA.) Cryomilling, involving milling at cryogenic temperatures, was used to process Ni aluminide powders in liquid N for up to 12 hours. 1 to 4wt% of N was absorbed by the alloy. Up to 2Ovol%AIN and 2%Al,O, were detected in the alloy. Various problems were outlined with the steps taken against them. Process modifications improved the properties of the cryomilled product, including greater homogeneity.
tored. Mg,Ge was the easiest to form. Synthesis of Mg,Si in metastable and equilibrium states was reported. Phase formation was discussed in terms of thermodynamics. DEVELOPMENT OF A PM PROCESS FOR MAKING NIOBIUM ALUMINIDE SI-IAFES J.H.Moll et al. (Crucible Research, USA.) Investigations aimed at the production of near net shapes in Nb,Al were described. Inert gas atomized powders, ceramic moulds and HIP were used. Special materials were used to allow use of high HIP temperatures. Nb was added to prealloyed powder to improve ductility. Some complex shapes were made. Structures and properties were described.
Composite materials EFFECTS OF HOT FORGING ON STRUCTURE AND PROPERTIES OF ALUMINIUM ALLOY coMFosITEs R.Angers et al. (Lava1 University, Canada.) It was reported that A16061-SiC composites had been hot forged from sintered preforms with the object of establishing the influence of process conditions of structure and properties. The results are held to demonstrate that hot forging of sintered compacts is a viable process route for metal matrix composites.
DEVELOPMENT AND APPLICATION OF RIP TECHNOLOGY
Intermetallic materials
H.Zheng et al. (Central Iron and Steel Research Inst., Beijing, China.) The paper reported on the use of HIP technology for processing a range of ferrous and non-ferrous materials for use in various applications. Equipment capacities and working limits were given as: size 69 by 110 cm, temperature maximum 2000°C and pressure 200 MPa.
PRODUCTION OF PM TITANIUM ALUMINIDE SHEET
DISTRIBUTION OF SILICON CARBIDE IN ALUMINIUM ALLOY COMPOSITE
H.Clemens et al. (Plansee Ag, Reutte, Austria.) The advantages of PM processing for production of yTiA1 over cast/ wrought technology were discussed. It was reported that compacts of Ti-48at%Al-2%Cr and Ti-48%Al-2% Cr-2%Nb had been produced from gas atomized powder and rolled into sheet. The fine grain size and homogeneity of the PM alloys were superior to those made from ingots. Mechanical properties were described.
F.H.Froes et al. (University of Idaho, Moscow, USA.) A comparison of ways of distributing Sic in A12024-5wt%SiC composites, based on experiment, was presented. The methods were ball milling of Al and Sic powders, rapid solidification of Sic flakes and solidification of Al alloy mixed with Sic into ingot. Powder and flake products were compacted and, with the ingot material, were extruded under high energy conditions, solution treated and aged to peak hardness. Distribution of Sic was discussed.
CALIBRATION OF CONSTITUTLVE MODEL FOR HOT ISOSTATIC PRESSING OF BORON POWDER PStutz et al. (University of Grenoble, Grenoble, France.) It was reported that HIP can be used to make net shape parts from B powder but care must be exercised in design of tools and HIP cycle. The need for a model to predict the behaviour of B powder during compaction was noted and a viscoplastic model describing the mechanical behaviour was presented. Experiments were described, using interrupted HIP 44
MPR December
1997
FORMATION OF INTERMETALLIC COMPOUNDS INMAGNESIUMALLOYS DURINGlWECBANICALALLOYING F.H.Froes et al. (University of Idaho, Moscow, Idaho, USA.) It was reported that MA had been used to process Mg-Sn, Mg-Ge and Mg-Si elemental powders. Synthesis of intermetallic compounds was moni-
INNOVATIONS IN PRODUCTION OF AL-ALLOY BABE METAL MATRIX COMPOSITES A.V.Bezroukov, A.I.Litvintsev. (Alspors Technology Ltd, Russia.) It was reported that A12124alloy(15 to 17%)SiC composites had been prepared by a spray deposition