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Processing of nickel-free materials
It was noted that little use has been made of warm compaction in production of automotive parts. Properties, including wear, of warm compacted parts were investigated. It was reported that engine sprockets had been made by warm compaction. Methods of controlling density and dimensional tolerances were discussed.
Development of undercut automotive engine part T.Hirao et al. (Nissan Motor Co. Ltd., Japan.) It was noted that it is difficult to make under-cut shape parts by any method. It was reported that an under-cut shape sprocket had been made on a computer controlled press with new design dies and tools. The process was described.
Modelling and simulation Experimental determination of densification function of metal powder M.f?rochu, S.Turenne. (Ecok Polytechnique de Montreal, Canada.) It was noted that considerable experimental effort is required to validate compaction models and that there may be large divergences between different sets of results. A review of previous experimental work was presented. Experimental techniques considered included isostatic-uniaxial, angled blocks and pre-corn, pacted methods. Results from these were compared and discussed.
Review of modelling of die compaction P.Breevin et al. (European Powder Metallurgy Associatwn, Shrewsbury, UK.)
High-fatigue strength material for high-stress parts without heat treatment M.Yoshidn et ai. (Kobe Steel Ltd., Japan.f
High fatigue strength of PM parts was discussed with regard to the need for heat treatment to achieve this. It was reported that a steel with high fatigue strength, which did not require heat treatment, had been developed. This was formed from a prealloyed Ni+ MO steel powder, a multi-component fine powder and Ni powder, added to enhance assintered fatigue strength. Fatigue, wear and impact properties were shown to be equivalent to, or better than, a 4%Ni-1.5%CuOS%Mo case hardened steel for use as a synchroniser hub.
Near net shape bearing caps K.Suganqu, M.Su,@moto. (Sumitomo
Electric industries
Ltd., Japan.) It was noted that bearing caps are conventionally made by machining from solid, expensive for close dimensional tolerance and that cost can be reduced by use of PM. Manufacture of PM bearing caps was described. The upper surface is formed by a single punch and the lower by 3 punches to control density distribution. Width accuracy is attained by a sizing operation which reduces the need for machining.
A European international collaborative project, PM MODMET, was reviewed. The exercise showed that the current state of technology is capable of accurately predicting density distriy butions and punch loadings on more simple shaped parts. More complex shaped parts are under investigation and it is shown that accum cy depends on assumptions concerning initial powder fill. The work carried out by the consortium was summarised and comments were made about future trends in modelling of compaction.
Inverse modelling of powder compaction - effect of friction and material behaviour
Analysis of powder compaction was reviewed. It was noted that experiments may not achieve homogeneity of relevant state conditions. To counteract this difficulty inverse modelling was studied to monitor powder pressing and to obtain material and friction parameters from tests under heterogeneous conditions. The importance of low,pressure conditions was emphasized. If correctly modelled it was shown that it is possible to model friction at low pressures in cylindrical die compression tests.
Design and evaluation of die pressing experiments for inverse modelling
Thermal spray forming of piston ring groove reinforcement K.Koduma et al. (Toyota Motor Corporation, [email protected] It was shown that to attain low emissions and low fuel consumption the operating terns perature and pressure of diesel engines has increased. This has imposed a need for higher wear resistance in top piston ring grooves. It was reported that a thermal spray technique had been used to reinforce the top ring areas of diesel engine pistons.
40
MPR
December
2001
Experiments for inverse modelling of compaction were described. A range of experiments were designed and evaluated.
Thermal-mechanical coupled analysis of warm compaction A.K.Ariffn
Coupled of warm
et al. (Kebangmun University, Malaysia.)
thermat-mechanical analysis compaction was carried out.
Development of a numerical model was described. The model was used to generate a green compact by uniaxial die compaction. The powder was assumed to be thermo-elastoplastic for which constitutive laws were derived. Yield criteria for parriculate materials and finite element methods were used. Equations were solved.
Quality management and environmental management Life-cycle assessment of powder metallurgy .I .Teengzeliur.(EGgantis AB, Hijguniis, Sweden.)
It was noted that PM is characterized by advantages of high utilization of material and low consumption of energy. A disadvantage lies in higher use of alloy elements. Life Cycle Assessment (LCA) was used to compare PM with other production methods. It was shownb how LCA can be used to evaluate different PM process steps and alloys for part manufacture in order to quantify environmental effects.
Processing of nickel-free materials P.Orth. (MIBA SintermetallAG, Vorch dorf, Austria.)
Widespread use of Ni was noted with respect to application in sinter-hardening steels and it’s high cost. It was reported that investiga, tions had been carried out with the object of developing steels free from Ni but with properties comparable with Ni steels. Results con, cerning powder characteristics, processing behaviour and properties were presented. Examples of parts made from the new alloys were shown.
Consolidation of iron-copper from recycled scrap
Difficulty in separating Cu from scrap Fe base alloys was noted. It was shown that PM provides a means of using the scrap Fe-& material instead of removing the Cu. A method of recycling scrap Fe-Cu was shown to be melting and rapid solidification to powder and heavy warm rolling to disperse the Cu evenly in the steel. A tensile strength of 1GPa and 8% elongation were attained.
Green forming of mechanically alloyed aluminium-silicon alloys T.Aizawa et al. (University of’%kyo, Japan.)
Use of Al-Si alloys was discussed. It was shown that mechanical alloying and warm compaction can produce Al-5 alloys with a fine structure more cheaply than by use of rapid solidification to powder. Production of a high Si alloy with a Si grain size of 5mm from cast Al-5 chips and fine Si powder was reported.
www.metal-powder.net
Development of undercut automotive engine part T.Hirao et al. (Nissan Motor Co. Ltd., Japan.) It was noted that it is difficult to make under-cut shape parts by any method. It was reported that an under-cut shape sprocket had been made on a computer controlled press with new design dies and tools. The process was described.
Modelling and simulation Experimental determination of densification function of metal powder M.f?rochu, S.Turenne. (Ecok Polytechnique de Montreal, Canada.) It was noted that considerable experimental effort is required to validate compaction models and that there may be large divergences between different sets of results. A review of previous experimental work was presented. Experimental techniques considered included isostatic-uniaxial, angled blocks and pre-corn, pacted methods. Results from these were compared and discussed.
Review of modelling of die compaction P.Breevin et al. (European Powder Metallurgy Associatwn, Shrewsbury, UK.)
High-fatigue strength material for high-stress parts without heat treatment M.Yoshidn et ai. (Kobe Steel Ltd., Japan.f
High fatigue strength of PM parts was discussed with regard to the need for heat treatment to achieve this. It was reported that a steel with high fatigue strength, which did not require heat treatment, had been developed. This was formed from a prealloyed Ni+ MO steel powder, a multi-component fine powder and Ni powder, added to enhance assintered fatigue strength. Fatigue, wear and impact properties were shown to be equivalent to, or better than, a 4%Ni-1.5%CuOS%Mo case hardened steel for use as a synchroniser hub.
Near net shape bearing caps K.Suganqu, M.Su,@moto. (Sumitomo
Electric industries
Ltd., Japan.) It was noted that bearing caps are conventionally made by machining from solid, expensive for close dimensional tolerance and that cost can be reduced by use of PM. Manufacture of PM bearing caps was described. The upper surface is formed by a single punch and the lower by 3 punches to control density distribution. Width accuracy is attained by a sizing operation which reduces the need for machining.
A European international collaborative project, PM MODMET, was reviewed. The exercise showed that the current state of technology is capable of accurately predicting density distriy butions and punch loadings on more simple shaped parts. More complex shaped parts are under investigation and it is shown that accum cy depends on assumptions concerning initial powder fill. The work carried out by the consortium was summarised and comments were made about future trends in modelling of compaction.
Inverse modelling of powder compaction - effect of friction and material behaviour
Analysis of powder compaction was reviewed. It was noted that experiments may not achieve homogeneity of relevant state conditions. To counteract this difficulty inverse modelling was studied to monitor powder pressing and to obtain material and friction parameters from tests under heterogeneous conditions. The importance of low,pressure conditions was emphasized. If correctly modelled it was shown that it is possible to model friction at low pressures in cylindrical die compression tests.
Design and evaluation of die pressing experiments for inverse modelling
Thermal spray forming of piston ring groove reinforcement K.Koduma et al. (Toyota Motor Corporation, [email protected] It was shown that to attain low emissions and low fuel consumption the operating terns perature and pressure of diesel engines has increased. This has imposed a need for higher wear resistance in top piston ring grooves. It was reported that a thermal spray technique had been used to reinforce the top ring areas of diesel engine pistons.
40
MPR
December
2001
Experiments for inverse modelling of compaction were described. A range of experiments were designed and evaluated.
Thermal-mechanical coupled analysis of warm compaction A.K.Ariffn
Coupled of warm
et al. (Kebangmun University, Malaysia.)
thermat-mechanical analysis compaction was carried out.
Development of a numerical model was described. The model was used to generate a green compact by uniaxial die compaction. The powder was assumed to be thermo-elastoplastic for which constitutive laws were derived. Yield criteria for parriculate materials and finite element methods were used. Equations were solved.
Quality management and environmental management Life-cycle assessment of powder metallurgy .I .Teengzeliur.(EGgantis AB, Hijguniis, Sweden.)
It was noted that PM is characterized by advantages of high utilization of material and low consumption of energy. A disadvantage lies in higher use of alloy elements. Life Cycle Assessment (LCA) was used to compare PM with other production methods. It was shownb how LCA can be used to evaluate different PM process steps and alloys for part manufacture in order to quantify environmental effects.
Processing of nickel-free materials P.Orth. (MIBA SintermetallAG, Vorch dorf, Austria.)
Widespread use of Ni was noted with respect to application in sinter-hardening steels and it’s high cost. It was reported that investiga, tions had been carried out with the object of developing steels free from Ni but with properties comparable with Ni steels. Results con, cerning powder characteristics, processing behaviour and properties were presented. Examples of parts made from the new alloys were shown.
Consolidation of iron-copper from recycled scrap
Difficulty in separating Cu from scrap Fe base alloys was noted. It was shown that PM provides a means of using the scrap Fe-& material instead of removing the Cu. A method of recycling scrap Fe-Cu was shown to be melting and rapid solidification to powder and heavy warm rolling to disperse the Cu evenly in the steel. A tensile strength of 1GPa and 8% elongation were attained.
Green forming of mechanically alloyed aluminium-silicon alloys T.Aizawa et al. (University of’%kyo, Japan.)
Use of Al-Si alloys was discussed. It was shown that mechanical alloying and warm compaction can produce Al-5 alloys with a fine structure more cheaply than by use of rapid solidification to powder. Production of a high Si alloy with a Si grain size of 5mm from cast Al-5 chips and fine Si powder was reported.
www.metal-powder.net