PM Disc Research Articles

Experimental-Base Analysis of the Effect of Adding PM Disc to the Hysteresis Motor Under Steady-State Conditions

Experimental-Base Analysis of the Effect of Adding PM Disc to the Hysteresis Motor Under Steady-State Conditions

Effects of Long Term Exposures on Fatigue of PM Disk Superalloys

Abstract Turbine disks in some advanced engine applications may be exposed to temperatures above 700°C for extended periods of time, approaching 1000 h. These exposures could affect near-surface composition and microstructure through formation of damaged and often embrittled layers. The creation of such damaged layers could significantly affect local mechanical properties. Powder metal disk superalloys LSHR and ME3 were exposed at temperatures of 704, 760, and 815°C for times up to 2020 h, and the types and depths of environmental attacked were measured. Fatigue tests were performed for selected cases at 704 and 760°C, to determine the impacts of these exposures on properties. Fatigue resistance was reduced up to 98 % in both superalloys for some exposure conditions. The changes in surface composition and phases, depths of these changed layers, failure responses, and failure initiation modes were compared.

A new TEM method for the characterization of the tertiary γ′ nano-precipitates in a PM disk superalloy: influence of ageing

An original method for characterizing the γ′-phase tertiary precipitates in a Ni-based superalloy manufactured by powder metallurgy is described. This investigation is made using post mortem transmission electron microscopy (TEM). It is based on the analysis of sheared areas within crept specimens, which allows the precipitates revealed by the dislocations in their glide plane to be observed. The characteristics of these nano-precipitates, i.e. their size, their volume fraction and the channel width between them, are determined for two different heat treatments (HTs). The results show a wide distribution of the microstructural parameters for a given HT, but only slight differences between the microstructures produced by the two different HTs. This microstructural information allows a better understanding of the wide variety of the deformation micromechanisms observed during creep at high temperature.

Performance characteristics improvement of a PM disk motor by using soft magnetic composite material

The paper presents a comparison of the magnetic field and magnetic characteristics of a PM disk motor with laminated magnetic stator open slot core, laminated magnetic stator closed slot core with soft magnetic composite and soft magnetic composite stator core. The data for this analysis is provided by a 2D FEM calculation of the magnetic field. After the proper modelling of the motor a calculation of the magnetic field for no load and current load is performed, for the three models. The results of the magnetic field distribution, air gap flux density distribution and the values of the magnetic and electric parameters for the three models are also presented.

Improved design of a novel PM disk motor by using soft magnetic composite material

This paper will present some aspects of soft magnetic composite (SMC) material application in electrical machines. The stator cores of the prototype axial field permanent magnet disk motor (PMDM), which is under consideration, are made of wound strip cores. Two types of PMDM stators are analyzed: laminated and SMC material stators. The comparison analysis is based on the production complexity and the magnetic properties and calculated parameters. The magnetic parameters under consideration are the flux densities in various sections of the magnetic circuit and the iron losses in these sections. The values for both types of stators are calculated using finite-element-method (FEM) analysis. The production complexity and the values of the magnetic parameters are in favor of the SMC material stators in relation to the laminated stators.

Clean melting of high strength PM disc alloys : S.J. Patel, I.C. Elliott, (INCO Alloys Ltd, Hereford, England)

Clean melting of high strength PM disc alloys : S.J. Patel, I.C. Elliott, (INCO Alloys Ltd, Hereford, England)