naa a22 4500 510823599 CHVBK 20180411083545.0 cr unu---uuuuu 180411e20131001xx s 000 0 eng 10.1007/s12541-013-0233-5 doi (NATIONALLICENCE)springer-10.1007/s12541-013-0233-5 Dimensional and geometrical precision of powder metallurgy parts sintered and sinterhardened at high temperature [Elektronische Daten] [Ilaria Cristofolini, Melania Pilla, Andrea Rao, Stefano Libardi, Alberto Molinari] The effect of the sintering and sinter-hardening temperature on the dimensional and geometrical precision of ring-shaped parts was investigated. The parts were produced with a 3%Cr-0.5%Mo-0.5%C steel, compacted to 6.8 g/cm3 and sinter/sinter-hardened at 1250°C, 1300°C and 1350°C. The increase in the sintering temperature enhances the fraction of load bearing section and leads to an expected significant improvement of mechanical properties. Dimensional shrinkage increases with the sintering temperature, however, the dimensional and geometrical precision obtained in all the cases is very good even at very high sintering temperature. Dimensional variations are anisotropic, and the effect of anisotropy was estimated by evaluating the lack of precision attained when green parts are designed assuming an isotropic behavior. Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg, 2013 Sintered steels nationallicence Sintering temperature nationallicence DG&T nationallicence Anisotropy nationallicence A : area of the cross section of the pore [μm2] nationallicence cext : circumference related to the external diameter in the sintered/ sinter-hardened part [mm] nationallicence cext 0 : circumference related to the external diameter in the green part [mm] nationallicence cint : circumference related to the internal diameter in the sintered/ sinter-hardened part [mm] nationallicence cint 0 : circumference related to the internal diameter in the green part [mm] nationallicence De : external diameter of the sintered/sinter-hardened part [mm] nationallicence De0 : external diameter of the green part [mm] nationallicence Deq : equivalent diameter of pore [μm] nationallicence Dext : required value for the external diameter of the final part [mm] nationallicence Di : internal diameter of the sintered/sinter-hardened part [mm] nationallicence Di0 : internal diameter of the green part [mm] nationallicence Dint : required value for the internal diameter of the final part [mm] nationallicence fcircle : shape factor nationallicence h : height of the sintered/sinter-hardened part [mm] nationallicence H : required value for the height of the final part [mm] nationallicence h0 : height of the green part [mm] nationallicence P : perimeter of the cross section of the pore [μm] nationallicence t : wall thickness in the sintered/sinter-hardened part [mm] nationallicence t0 : wall thickness in the green part [mm] nationallicence w : maximum deviation of measured θ from the nominal value in the sintered/sinter-hardened part nationallicence w0 : maximum deviation of measured θ from the nominal value in the green part nationallicence ΔV/V0 : volume change nationallicence Δθ : maximum difference between θ in the sintered/sinter-hardened part and θ in the green part nationallicence Φ : fraction of load bearing section nationallicence ɛ : fractional porosity nationallicence ɛi : isotropic dimensional change nationallicence ɛr : dimensional change in the radial direction nationallicence ɛz : dimensional change in the axial direction nationallicence ɛθ ext : dimensional change in the tangential direction in the external circumference nationallicence ɛθ int : dimensional change in the tangential direction in the internal circumference nationallicence θ : angle formed by the median planes of the grooves in the sintered/ sinter-hardened part [°] nationallicence θ0 : angle formed by the median planes of the grooves in the green part [○] nationallicence Cristofolini Ilaria Department of Industrial Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy aut Pilla Melania Department of Industrial Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy aut Rao Andrea R & D Key — RK S.r.l., Viale Caproni 7, 38068, Rovereto (Trento), Italy aut Libardi Stefano TFM Group, Via del Lavoro 32, Grisignano (Padova), Italy aut Molinari Alberto Department of Industrial Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy aut International Journal of Precision Engineering and Manufacturing Springer Berlin Heidelberg 14/10(2013-10-01), 1735-1742 2234-7593 14:10<1735 2013 14 12541 https://doi.org/10.1007/s12541-013-0233-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12541-013-0233-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cristofolini Ilaria Department of Industrial Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy aut NATIONALLICENCE 700 1- Pilla Melania Department of Industrial Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy aut NATIONALLICENCE 700 1- Rao Andrea R & D Key — RK S.r.l., Viale Caproni 7, 38068, Rovereto (Trento), Italy aut NATIONALLICENCE 700 1- Libardi Stefano TFM Group, Via del Lavoro 32, Grisignano (Padova), Italy aut NATIONALLICENCE 700 1- Molinari Alberto Department of Industrial Engineering, University of Trento, Via Mesiano, 77, 38123, Trento, Italy aut NATIONALLICENCE 773 0- International Journal of Precision Engineering and Manufacturing Springer Berlin Heidelberg 14/10(2013-10-01), 1735-1742 2234-7593 14:10<1735 2013 14 12541 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer