Interparticle Neck Connections in Innovative Insulated Iron Powder Compounds

Abstract

Goal of the present paper is the analysis of the interparticle neck connections in a system made of insulated iron powder compounds with dierent additions of an AlMgSiCu alloy (0.25, 0.5 and 0.75 wt%). The introduction of the aluminium alloy powder has been made in order to improve the mechanical properties, evaluated as the transverse rupture strength, without decreasing the magnetic properties (evaluated in terms of iron loss and coercivity force). The fracture analysis of investigated systems puts into evidence the breaking of interparticle neck connections. Heat treatment (at the temperature of 500• C) contributes to the early stages of interparticle neck developments. The chosen aluminium alloy presents a sort of pre-sintering behaviour at 500• C, with the possibility of mass-transport processes around the insulated iron powder compounds. The air heat treatment applied aims at providing an increase in the mechanical behaviour of the material, with a nal good rigidity after the cooling process. Fracture surfaces and transverse rupture strength values show that, at 500 MPa, the strength and the area related to the inter-particle necks can be correlated to the occasional broken insulated point-to-point surfaces that hinder the development of inter-particles necks.

FABRICATION OF TRANSPARENT MgAl2O4 SPINEL CERAMICS BY PECS PROCESSING OF COMBUSTION - SYTHESIZED NANOPOWDERS

“…4a). Moreover, most of the grains were in submicron sized and the interparticle necks were not occurred in comparison with sintered alloys [20]. Grain sizes distribute in a narrow range from 0.3 m to 0.7 m with the average value of 0.48 m (Fig.…”

The Impact of Shear Gap Size on the Quality of the Sheared Surface in Electrical Steel Sheet Blanking

“…Low magnetic losses reduce heat generation and energy consumption. Mechanical properties affect shearability, resistance to fatigue fracture resulting from sudden changes in mechanical stress and resistance to material deformation at high rotor or stator speeds [3][4][5]. The chemical composition of these steels is similarespecially as far as the basic alloying elements are concerned, and the manufacturing processes have not changed significantly for years.…”

Heat Treatment Effect on Interface Microstructure and Hardness of a Medium Carbon Steel Cladded by Aisi 316 Stainless Steel

“…Often a hardness peak is detected at stainless/carbon steel interface [38]: such peak needs to be carefully taken as low as possible for the possible deleterious effect they should excerpt in the material performance. Therefore, a specific heat-treatment is required in order to improve hardness values at metals interface [39][40][41][42][43][44][45]. Aim of this paper is to analyze the interface properties of a austenitic stainless steel cladded by carbon steel.…”