Magnetic properties of Cu–Mn–Sb alloys containing 4.98∼59.80% Mn and 10.03∼79.71% Sb have been measured. It has been found that the alloys consisting of about 17∼40% Mn, 10∼54% Sb and 9∼65% Cu show high coercivity when tempered at 150°∼650°C after chill-casting and the alloy consisting of 22.04% Mn, 33.00% Sb and the rest Cu exhibits the highest coercive force _IH_C of 2000 Oe and a residual intensity of magnetization Ir of 12 e.m.u. It has further been determined by means of electron microscopic observation and X-ray analysis that these high-coercivity alloys contain many acicular fine particles of the ferrimagnetic compound Mn₂Sb dispersed in the matrix of the nonmagnetic α_Cu phase. The high coercivity of these alloys is probably caused by the energies of crystal magnetic anisotropy and shape magnetic anisotropy of these small particles composed of a single magnetic domain.

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Measurements of the Young’s moduli, Hardness and temperature coefficients of the modulus at room temperature were carried out so as to investigate the effects of 0.1∼3.0% additions of 25 third elements on the properties of Pd–Au alloys “Pallagold”, 45, 50 and 55% Au, when annealed at 1000°C for 1 hr or further heated at 360°C after water quenching and cold working, respectively. The third elements added were Pt, Ir, In, Ta, Ag, Fe, Ni, Co, Mn, Cu, V, Mo, W, Sb, Sn, Zn, Cr, Al, Ti, Si, Cd, Be, Zr, B and Nb. The results show that the Young’s modulus and hardness in the ternary alloys are in general larger than those in the binary alloys, and also that the temperature coefficient of the modulus in negative sign is increased by the addition of the third elements.

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The thermal expansion coefficient and the temperature coefficient of Young’s modulus in nickel-copper alloys have been determined with a vertical dilatometer previously designed by one of the present authors and by means of a vibrator-controlled oscillator system, respectively. And it has been found that the mean linear coefficient of thermal expansion (0°∼40°C) vs. composition curve against the composition axis is convex in the ferromagnetic region and concave in the paramagnetic region and also the mean temperature coefficient (0°∼40°C) of Young’s modulus shows negative values in the whole composition range of the alloys except the maximum value of +2.1×10⁻⁵ in the alloy containing 29.85% Cu.

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The thermal expansion and Young’s modulus of the cobalt and palladium alloys have heen measured in the temperature range from 0° to 990°C with a dilatometer and by means of an electrostatic vibrator-controlled oscillator system, respectively. It has been found that the mean linear coefficient of thermal expansion (0°∼40°C) shows a maximum value in the α phase alloy containing 90% Pd which has a ferromagnetic Curie Point of 150°C and the mean temperature coefficient of Young’s modulus (0°∼40°C) shows a positive value in the composition range of 90.5∼95% Pd, its largest positive value being +59.78×10⁻⁵ in the alloy containing 94% palladium.

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Structural changes in copper single crystals during high temperature creep deformation were investigated by means of the Berg-Barrett method. Creep tests were performed in argon atmosphere at 0.75 Tm=745°C and 0.85 Tm=880°C (Tm : the melting temperature in degrees Kelvin). In order to obtain the three-dimensional information on the substructures, two kinds of observation surfaces were prepared by cutting the specimens crept to various strains electrochemically : one parallel to the primary slip plane (111) and the other parallel to the (\bar101) plane on which deformation bands due to the primary slip are formed. A third observation surface is the original specimen surface, i.e. the (1\bar21) plane which is normal to the lattice rotation axis in the deformation band.
In the transient creep stage pillar-like subgrains elongating in the direction of [1\bar21] were observed. They were surrounded by sub-boundaries parallel to the (111) and (\bar101) plane which were twist and tilt boundaries, respectively. Spacings between the sub-boundaries were about 30∼50 μ at 745°C and 50∼100 μ at 880°C; the spacings remained almost the same throughout the steady-state creep stage. In the examination of the (111) plane, apparent lattice twisting of the (111) plane about the [1\bar21]-axis was found with a period of about 10 μ. The increase in the twist angle was the most remarkable structural change during creep deformation.

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Dislocation arrangements and substructure formation due to high-temperature creep deformation were investigated in copper single crystals by means of the etch-pit technique. Etch-pit observation was made on the surfaces parallel to the primary slip plane, (111), and to the critical slip plane, (\bar111).
At an early stage of transient creep, in some regions, which will be called “region A”, subgrains elongating in the direction of the deformation band (10∼20μ×50∼200μ in size) were seen in the (111) observation. Cell structures (cell size : ∼100μ) were observed in the other regions, which will be called “region B”, adjacent to region A. Regions A and B were bordered along the plane of the deformation band, (\bar101). With the progress of transient creep deformation, the width of the long subgrains in region A increased and the cells in region B changed into well-developed subgrains, decreasing in their size. At the end of transient creep the width of the long subgrains in region A and the size of subgrains originating from the cell structures in region B were 20∼40μ and ∼50μ, respectively. The facts show that the structures in regions A and B tend to become similar with creep deformation. During steady-state creep, little change occurred in the shape and size of the substructures.
Many primary dislocations were observed within the subgrains and the cells in transient creep. The primary dislocations, which were generated during instantaneous elongation, decreased in transient creep and increased slightly in steady-state creep.

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Fine regular structures are occasionally visible in the grain boundary of an annealed Fe–Mn alloy when observed in a high-voltage electron microscope. They are in the form of either an array of dislocations or serrations in the grain boundary. The orientation relationship between the neighboring grains was near one of the coincidence relationships and the grain boundary plane corresponded to one of the densely packed planes of the coincidence site. The structure and possible behavior of such dislocation array in the coincidence boundary were considered theoretically.
It was concluded that the Burgers vector of the boundary dislocation makes up a three-dimensional lattice which depends on the coincidence system but is independent of the boundary plane orientation. Each boundary dislocation is generally bound to a step in the grain boundary whose height depends on the boundary plane on which the dislocation is located. The Burgers vectors of lattice dislocation form superlattice with the Burges vectors of the grain boundary dislocation. Therefore, a lattice dislocation on arriving at the grain boundary disintegrates into grain boundary dislocations if the temperature is high and grain boundary diffusion is active. The Burgers vector of some of the grain boundary dislocations are parallel to the coincidence grain boundary. However, the Peierls stress for the gliding of the boundary dislocation appears to be generally high.

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The mechanism which dominates the flow stress and work-hardening of pearlitic steel at small strains is investigated from both the analysis of tensile properties and microscopic observations of slip patterns. The flow stress and the work-hardening rate are shown to increase linearly with an inverse square root of the mean free ferrite path. The flow behavior of pearlite is characterized by the increase in the Petch slope with strain and by the minor dependence of the flow stress and work-hardening on the strain rate. Analysis of a strain-rate cycling experiment shows that a large part of the flow stress is the long-range internal stress and that the effective stress acting on dislocations is almost the same as that in ferritic iron. Microscopic observations have revealed that the increase in the density of dislocations takes place preferentially along the ferrite-cementite interface and that slip bands extend along the grain boundaries and through the gaps of lamellar cementites. Shear of cementites is eventually observed at the intersections with slip bands. Such features of the deformation of pearlite are consistently explained by the model that dislocations, which are generated at the interface between cementite and ferrite rather than those multiplied within the ferrite grains, develop a large amount of long range internal stress within the pearlitic ferrite. Deformation of cementites is not likely to affect the flow stress or work-hardening of pearlite.

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Transmission electron and optical microscopic observations were made on the Ni-24.4 at% Mo alloy (nearly stoichiometric Ni₃Mo) to clarify the decomposition process during isothermal annealing after quenching from the α-region (face-centered cubic structure).
It is found that the alloy quenched from the α-region shows a short-range order similar to that found in the Ni₄Mo alloy, and when annealed isothermally below the peritectoid temperature, γ(Ni₃Mo) does not precipitate directly from the short-range-ordered matrix, but a meta-stable phase Ni₂Mo (Pt₂Mo type superlattice) does. These precipitates of Ni₂Mo are lenticular in shape and grow to plates. The habit plane of the plate-shaped Ni₂Mo precipitates is of the {110}_α type. With increase in annealing time, β(Ni₄Mo) precipitates in the matrix, and Ni₂Mo and β coexist. On the other hand, γ nucleates predominantly at grain boundaries of α and grows. When annealed for a longer time, γ predominates by consuming the pre-existing Ni₂Mo and β.
The orientation relationships of each of precipitates (Ni₂Mo, γ and β) with the matrix were determined.

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Hardness test, electrical resistivity measurement, and electron microscope observation were carried out on arc-melted beryllium specimens with up to 0.2 wt% iron which were heat-treated at 900°C and aged at 400° to 700°C for various times.
From the results it was deduced that the amount of small dislocation loops produced probably by precipitation of excess quenched-in vacancies increased with increasing iron content, and that the vacancies combined preferentially with iron atoms, which resulted in the slowing down of their migration rate. The amount of the loops increased by the subsequent ageing, accompanied with the precipitation of iron onto the loops as well as onto other defects such as grain boundaries and dislocation lines.

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The coercive force _BH_C of the intermetallic compound SmCo₅ is not sufficient for its application as a permanent magnet in the cast state. This study deals with increasing of the coercive force of the SmCo₅ alloy system. Specimens are melted in an arc melt furnace which has the tungusten electrode and inactive gas Ar.
The directional magnetic properties are observed in the SmCo₅-SmCu₅ system alloy, as a result of freezing in a direction normal to the cold surface of the copper hearth. The maximum energy product, (BH)_max, of the 65 wt% SmCo₅-35 wt% SmCu₅ alloy has 5.78 MGOe in the as-cast state, when the measurement is carried out in a direction perpendicular to the chill plane. By annealing at 300°C for 1 hour, the (BH)_max value increases to 7.73 MGOe with Br 6450 G and _BH_C 3400 Oe. The magnetic properties in the direction perpendicular to the chill plane are superior to those in other directions and the chill plane shows a weak texture, (0001). These alloys have the easy direction of magnetization, which is the c-axis of the hexagonal crystal as in the case of SmCo₅.
The lattice constants of both a- and c-axes of the hexagonal crystal enlarge linearly with increasing copper content in alloy. The value of lattice constant ratio c⁄a keeps approximately 0.802 in all the alloys investigated.

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