G. Y. Chin

New ductile Cr‐Co‐Fe permanent magnet alloys for telephone receiver applications

Cr‐Co‐Fe permanent magnet alloys have been investigated for potential replacement of Remalloy in the U‐type ring armature telephone receiver. Of particular interest would be an alloy which could be cold drawn into cup shape. Small additions of Al, V, Nb, Ti and Zr were added to the basic 28%Cr–15%Co–Fe ternary in an attempt to suppress γ phase formation and improve cold formability. As a result of extensive investigation we have discovered two Zr bearing alloys that are highly promising for fabrication as receiver magnets. One alloy consists of 0.25%Zr–1%Al and the other 0.25%Zr–0.25%Ti–1%Nb. After suitable heat treatment they yield values of Br=9600 G, Hc=460 Oe, BHmax=1.9×106 GOe and Br=8900 G, Hc=440 Oe, BHmax=1.8×106 GOe respectively.Cr‐Co‐Fe permanent magnet alloys have been investigated for potential replacement of Remalloy in the U‐type ring armature telephone receiver. Of particular interest would be an alloy which could be cold drawn into cup shape. Small additions of Al, V, Nb, Ti and Zr were added to the basic 28%Cr–15%Co–Fe ternary in an attempt to suppress γ phase formation and improve cold formability. As a result of extensive investigation we have discovered two Zr bearing alloys that are highly promising for fabrication as receiver magnets. One alloy consists of 0.25%Zr–1%Al and the other 0.25%Zr–0.25%Ti–1%Nb. After suitable heat treatment they yield values of Br=9600 G, Hc=460 Oe, BHmax=1.9×106 GOe and Br=8900 G, Hc=440 Oe, BHmax=1.8×106 GOe respectively.

A low cobalt ternary Cr-Co-Fe alloy for telephone receiver magnet use

The processing, structure, and properties of a low-cobalt, ternary Fe-28Cr-10.5Co isotropic magnet alloy (Chromindur II), developed for use in the telephone receiver, are described. The new alloy is easy to process, and permits a convenient low-temperature recrystallization anneal of heavily cold rolled strips leading to a fine-grained, ductile, single-phase structure suitable for cold forming into the desired magnet shape prior to aging. Optimization of the microstructural control process during spinodal decomposition is discussed with a particular emphasis on solving the problem of critical control during aging required for desirable magnetic properties. It is shown that, in order to reproducibly achieve an optimum combination of wavelength and amplitude during decomposition, two drastically different continuous cooling curves, connected at some intermediate temperature, must exist. This newly devised, two-stage aging technique permits a reasonably wide heat treating window, and accomodates heat-to-heat compositional variations. Satisfactory isotropic magnet properties are reproducibly obtained by industrial heat treatment leading to a successful commercial application of the new alloy in the ring armature type telephone receiver.

Competition among {110}, {112}, and {123} slip modes in BCC metals

The conditions for the activation of various combinations of {ll0} <111>, {112} <1ll>, and {123} <111> slip modes have been examined by analyzing the yield loci. It is found that {ll0} slip will occur in preference to the other two modes if α > 1.155 and α2 > 1.134, where α1 and α2 are respectively the critical resolved shear stress for slip on {112} and {123} systems relative to {ll0} slip. Slip occurs on {112} systems alone if α1 < 0.866 and α1 < 0.917α2: and on {123} systems alone if α2 < 0.945 and α2 < 0.982α1. The influence of {112} slip asymmetry and {112} <111> twinning on the choice of deformation modes has also been analyzed.

Lateral constraints in plane strain compression of single crystals

AbstractIn plane strain compression tests where the walls of a channel suppress lateral flow, the lateral stress developed at the walls varies with the crystal orientation. We have applied a crystal plasticity analysis to calculate the ratio of lateral stress (σyy) to the compression stress (σxx) for fcc crystals compressed on the (110) plane and extended in various directions in (110). It was found that σyy/σxx is equal to zero from (110)[001] to

Plastic deformation of V3Si single crystals at elevated temperatures

(110)[\bar 112]

Directional solidification of Co-Cu-R permanent-magnet alloys

, at which point it rises discontinuously to a value of 1.5. It then decreases to a value of 1.0 for

Hardness and bounding in A15 superconducting compounds

(110)[\bar 111]