An investigation was conducted of the relationship between the orientations of recrystallized grains, the deformation amount and the tensile temperature with the tapered single crystals of A1 and Cu. In A1 single crystals, the orientations of recrystallized grains became concentrated when plastic deformation fully entered into the third work hardening stage during tensile test at—78—300℃, and had a crystallographic relationship with the deformed parent in rotating around the [111] about 30—50°, but it was rand random after tensile test at—196℃. In Cu single crystals, the orientations of recrystallized grains were also radom after tensile test at 20—400℃.In consideration of the difference of stacking fault energy in AI and Cu and in A1 with decreasing temperature, the deformed structure in third work hardening stage would be different. From the point of view that the nucleation of recrystallization occurred by the growth of subgrains of large difference in orientation with surrounding matrix and of taking the lead during the recovery process, the different relationship between the orientations of recrystallized grains and the deformed parent can be explained.

Brief historical details concerning the defects of solid helium are reviewed.The plastic deformation in hop ~4He, anomalous temperature dependence of the sound velocity and the force for the steady creep in ~4He and bcc ~3He are discussed.

A study was made of the electron diffraction patterns of extracted μ-phase which identified with that of X-ray powder diffraction in superalloy GH302.It is shown that the reflections with—h+k+l≠3n spots, e.g. {100}, {200},etc.in [C01] zone and {110},{101}, etc. in [111] zone (indexed as hexagonal) are forbidden for the R3m space group. These "forbidden" diffractions cannot be attributed to double diffraction with neither non-zero Laue zone nor other phases such as MgZn_2 type Laves phase. Based on diffraction extinction law, it seems to be a primitive hexagonal lattice (P6). Its lattice constant is consistent with that of μ-phase (R3m) described as hexagonal. It may be a kind of local-ordering structure of μ-phase.

The effect of temperature at slag face on A1 and Ti control and the relation between temperature distribution round liquid metal pool/molten slag pool interface and quality of ingot surface have been investigated during ESR process of superalloy. If the insulation of the mould from its base plate was poor and rather higher temperature appeared at slag face, in the later refining stage the rate of O_2 penetration to slag from atmosphere,ν_(s—g)~(O2),is 2—3 times faster and also in the earlier stage the tendency towards the A1 increasing is greater than that of good insulation. An increase in voltage may cause the temperature at slag face to rise and the Ti loss to accelerate, e.g. every 0.03% more Ti loss at nearly 1 V increased.The temperature distribution round liquid metal pool/molten slag pool interface may be expressed by t=ae~(B/d)(B<0), it has a great influenc upon the quality of ingot surface. The method to ascertain this temperature distribution is presented.The evaluation of quality may be proposed by the change of slag coating thickness, δ=B/(ln t_1—lna). It is shown that the quality of ingot surface is perhaps depended on the electric current distribution in the molten slag pool, the heat conducting conditions at mould wall, the liquidus temperature of slag and the change of all factors affecting the temperature at "high temperature region".

Studies were made on high pressure hydrogen reduction of Ni ammoniacal solution to metallic Ni with fine Ni powder, which was also prepared by hydrogen reduction with Cr~(2+) as nucleating agent, added as solid seed. Results indicate that the reduction was carried out under chemical reaction rate control region. The rate of reduction is proportional to the amount of Ni powder as solid seed added,and to the square root of partial pressure of hydrogen and is not influenced by the concentration of Ni ion in solution up to most of Ni reduced. Both activation of hydrogen molecules and phase transformation of Ni are believed to proceed on the surface of Ni powder added. Reaction can be considered to proceed according to the following scheme with reaction 4 as the rate controlling step:(5) 2H~++2NH_3=2NH_4~+ fast

The deterioration of aluminide coating formed on two cast nickel-base superalloys by pack cementation or by vapour calorizing under reduced pressure has been investigated.To evaluate the coating stability, the oxidation tests were made by exposure to static air under 800-1000℃ for 3000-5000 h or 1100℃ for 100 h.The microstructures of these coatings formed not only by both processes but also on both alloys are quite similar. It is observed that the outer zone of coating consists mainly of NiAl and Ni_2A1_3 phases on which the Ti (C, N) and Al_3Ti are dispersed; and the inner zone is composed of NiA1, Ni_3Al, Ti(C, N), M_(23)C_6 and M_6C near the underlying metal. The deterioration of the aluminide coating after a long-term exposure at elevated temperature seems to be closely related to the phase transformation of the outer zone, the sequence of whic(?) may be as follows:Ni_2Al_3+NiAl(enriched in Al)→NiAl(enriched in Ni)→→-NiAl+Ni_3Al→Ni_3Al→Ni_3Al+γ The Ni_2Al_3 and NiAl(enriched in Al) phases are extremely unstable and disappear after a short exposure below 1000℃, while NiAl(enriched in Ni) phase is very stable and not even altered to Ni_3Al after oxidized at 900℃ for 5000 h. The nucleation of the Ni_3Al phase along the grain boundary of NiAl indicates the initiation of coating deterioration. An end of its deterioration is that the transformation of NiAl into Ni_3Al+γ is just finished. The granular phases in the inner zone are carbides,mainly as M_(23) C_6 or M_6C differing with either alloy, all of them disappear at1100℃. It is also found that the σ phase in the diffusion zone may be vanished after 100 h exposure at 1000℃.

Changes in the structure and the magnetic domain patterns in amorphous Gd-Co alloy films after annealing at room temperature in a low vacuum of 10~(-2) mmHg for 2 weeks as well as heating in a high vacuum of 5×10~(-7) mmHg were investigated by electron diffraction and Lorentz electron microscopy. It was found that the phase separation could be achieved either by annealing at room temperature in low vacuum or by heating in high vacuum.The diffraction intensity profiles of the films and their magnetic domain patterns were changed as a result of phase separation. The nearest neighbor coordination number between Gd and Co atoms was obviously decreased, meanwhile the magnetic bubbles in the domain patterns were apparently decreased or even disappeared, resulting in the fact that the in-plane domain appeared. This probes once again that the magnetic anisotropy in amorphous Gd-Co alloy films is definitely related to the nearest neighbor coordination number between Gd and Co atoms and that the latter may be intuitively shown in the electron diffraction intensity profile.It was also found that during heating at 350℃, Co crystallized first with α-Co as its main product and β-Co the subordinate. The α-Co gradually transformed into β-Co with the increase of temperature. The oxidation of Co had not been observed even at 950℃ while Gd was oxidized seriously before its crystallization.No trace of Gd-Co alloy or metal Gd could be found in the whole process of crystallization.The change of the magnetic domain patterns with the heating temperature was shown in the present paper. The influence of both the phase separation and the degree of short range order on the magnetic anisotropy in films was discussed.

A study was made of the optimum composition of 2-17 type Sm(Co, Cu, Fe,Zr)_z magnets. It shows that Sm content is about 27 wt%, instead of 25.5 wt% reported by Ojima. It is shown that the liguid phase sintering process, quite other than a simple solid phase sintering, is favourable to control and to adjust exactly their compositions, to play fully the active role in step aging treatment, to enhance strongly the coercivity and the energy product and to prepare successfully magnets with excellent properties. The highest valuc of energy product, 30.5 MGs·Oe, has been obtained.

The Suitable contents of such effective constituents determined on the basis of the MnS process may be available to produce the oriented-grain Fe-3%Si as:C 0.03-0.05%, Mn 0.06-0.08%, S 0.018-0.025%, [Mn] [S]=(11-20)×10~(-4) and O_2 0.007%. The magnetic properties of Fe-3%Si have also been influenced by the slab reheating temperature. It was observed that with the raise of the reheating temperature, the primary grain size reduced and the secondary coarsened, thus,its magnetic properties may be remarkably improved, B_(10)>1.78Wb/m~2, and stabilized.The proper reheating temperature is elevated as the increase of product [Mn] [S].However, the reheating temperature became relatively insensitive to the magnetic properties when an appropriate amount of Al and N_2 was added. The secondary grains may coarsen and value B_(10) may improve further. The starting temperature of the secondary recrystallization seems to be in correspondance with that at the beginning of rapid growth of primary grains and of the aggregation of MnS particles.

The fine grains in the product of oriented-grain silicon steel sheet with high induction has been investigated using metallographic etch pits technique. It was Shown that by the slab reheated under an exceedingly high temperature,the hot rolled band of large elongated grain structure may be produced, and its {100}<011>-<001> components in the primary recrystallization texture enhanced.In these regions the primaries are enlarged and the lined grain structure is appeared after final annealing, while the slab reheated under lower temperature, the product in which the solution of the MnS and A1N has not be completed yet,may be obtained with mixed grain structure. In addition, it is presented that the lined fine grain structure could be reduced or prevented by increasing carbon content of the steel, by raising hot reduction or by adopting two stages in cold rolled process.

The effect of FeO_n on the properties of converter end slag (low P content)has been studied with phase diagram analysis and petrograph observation. Referring data taken from end slag of oxygen blown converter to the CaO-SiO_2-FeO_n system, the phase equilibrium under elevated temperatures is calculated and regressed.Thus, the relationship between FeO_n contained and percentage of balanced liquid phase in converter slag (low P content), of which C_2S, C_3S and CaO already crystallized out, may be obtained. It is demonstrated that adjustment of FeO_n content is significant of relation to the properties of the converter end slag.Furthermore, certain problems such as the slag viscosity, "slag melting" and slag making with respect to slag properties have also been discussed.

An attempt was made to ascertain the correlation of equilibrium constant of the polymerization of binary silicate melts with the chemical bond parameters such as ratio of the effective nuclear charge of metallic ion to its radius, as well as the ionization potential and electronegativity in Allred-Rochow scale. The three-parameter equation derived was employed to estimate the equilibrium constant by which the polymerization of certain binary silicate systems is characterized. It was also evaluated the activities of metallic oxides, the anion distribution in silicate and mean chain length, etc. in connexion of expression of polymerization.The result is shown that both free oxygen ion concentration and degree of silicate polyanion polymerization increase with the increase of the charge-radious ratio, ionization potential and electronegativity in Allred-Rochow scale.Fair agreement of the calculated values of activities was found with the experiment data. This may be available to predict some properties of silicate melts.

The bond parameter approach to the wetting behaviour of molten glass on certain Pt alloys was attempted on the basis of their equilibrium contact angle tests. It seems to indicate that the dependence of the wetting behaviour on the bond parameters of pure metals, and Pt-alloy constituents as well as glass components itself may be qualitatively generalized.

Using the method of linear response theory in lattice dynamics on the basis of Tyson's model, the response displacements of atoms on cleavage plane at the incipience of brittle fracture was derived and an expression for evaluating brittle fracture surface energy of metals was found. The brittle fracture surface energy for a number of bcc and fcc metals has been calculated and the results coincide with order of magnitude in experimental measurements.

Based upon the linear relationship between Δα and Δ_p of cracked specimen in the stable growth stage and after yielding of the toughness band, a new method using double-specimen for J_(IC) testing was developed by essential estimation of medium or high toughness materials. Its simplicity and accuracy may be available to the industrial laboratories on the requirement of engineering design.

An investigation of self-powdering of RE-Si-Fe alloy was conducted by means of X-ray diffraction analysis and electron microscopy. It is identified that the presence of REP, or CeC_2, La_2C_3 may be the cause of self-powdering when it exposed to weather or soaked in water. Its self-powdering behaviour is aggravated by both hydrogen embrittlement and stress corrosion.