摘要:
A method for surface processing at least a portion of a component of zirconium or hafnium alloy, including at least one operation of nanostructuring a surface layer of the alloy so as to confer on the alloy over a thickness of at least 5 μm a grain size which is less than or equal to 100 nm, the nanostructuring being carried out at a temperature which is less than or equal to that of the last thermal processing operation to which the component was previously subjected during its production.Component of zirconium or hafnium alloy processed in this manner.
摘要:
A method for producing a wear-resistant and corrosion-resistant stainless steel part for a nuclear reactor is provided. This method comprises steps of providing a blank in stainless steel; shaping the blank; finishing the blank to form the part in stainless steel, the finishing step allowing the prevented onset or the removal of work hardness on the outer surface of the part; hardening the outer surface of the part via diffusion of one or more atomic species.
摘要:
A cylindrical thin-wall sleeve including an SiC fiber-reinforced SiC composite material (SiC/SiC), which has a porosity of 40% or less and a wall thickness of 5 mm or less.
摘要:
A composite, copper clad neutron absorbing material is comprised of copper powder and boron powder enriched with boron 10. The boron 10 content can reach over 30 percent by volume, permitting a very high level of neutron absorption. The copper clad product is also capable of being reduced to a thickness of 0.05 to 0.06 inches and curved to a radius of 2 to 3 inches, and can resist temperatures of 900.degree. C. A method of preparing the material includes the steps of compacting a boron-copper powder mixture and placing it in a copper cladding, restraining the clad assembly in a steel frame while it is hot rolled at 900.degree. C. with cross rolling, and removing the steel frame and further rolling the clad assembly at 650.degree. C. An additional sheet of copper can be soldered onto the clad assembly so that the finished sheet can be cold formed into curved shapes.
摘要:
A dense essentially non-porous composite ceramic material of a diboride of group IVa metal, preferably titanium, and alumina in a 3:5 mole ratio has a macroscopically uniform structure made up of non-uniformly dispersed agglomerates of alumina of random shapes and dimensions and a fibrous sponge-like electrically conductive structure of submicronic grains of the group IVa metal boride in intimate wetting contact with the alumina agglomerates. The material is made by reaction hot pressing of coarse grain precursor powders.
摘要:
A neutron-absorber body for use in burnable poison rods in a nuclear reactor. The body is composed of a matrix of Al.sub.2 O.sub.3 containing B.sub.4 C, the neutron absorber. Areas of high density polycrystalline Al.sub.2 O.sub.3 particles are predominantly encircled by pores in some of which there are B.sub.4 C particles. This body is produced by initially spray drying a slurry of Al.sub.2 O.sub.3 powder to which a binder has been added. The powder of agglomerated spheres of the Al.sub.2 O.sub.3 with the binder are dry mixed with B.sub.4 C powder. The mixed powder is formed into a green body by isostatic pressure and the green body is sintered. The sintered body is processed to form the neutron-absorber body. In this case the B.sub.4 C particles are separate from the spheres resulting from the spray drying instead of being embedded in the sphere.
摘要翻译:用于核反应堆中的可燃毒物棒的中子吸收体。 身体由含有B4C,中子吸收剂的Al2O3基体组成。 高密度多晶Al2O3颗粒的区域主要被孔隙包围,其中一些有B4C颗粒。 该主体通过首先喷雾干燥已经加入粘合剂的Al 2 O 3粉末的浆料来生产。 将具有粘合剂的Al 2 O 3的团聚球的粉末与B4C粉末干混。 混合粉末通过等静压力形成生坯,并将生坯烧结。 将烧结体加工成中子吸收体。 在这种情况下,B4C颗粒与喷雾干燥而不是嵌入球体中的球体分开。
摘要:
This invention relates to a composite plate shaped billet, useful in the fabrication of nuclear control rods, which comprises a core of stainless steel containing about 2% Boron 10, a thin coating of zirconia on the surfaces of said core, said core and said zirconia coating being completely encased in a jacket of mild steel, said composite having been hot rolled between about 1075.degree. and about 1165.degree.C.
摘要:
A process for low temperature sintering of rare earth and actinide oxides which have a cubic to monoclinic transformation by heating a powder compact at a temperature just above the transformation temperature.
摘要:
IN THE FABRICATION OF POROUS METAL BODIES, AND IN PARTICULAR, CONTROL BODIES FOR NUCLEAR REACTORS WITH OR WITHOUT INTEGRAL FUEL MATERIAL, BY POWDER METALLURGICAL TECHNIQUES, THE UTILIZATION OF A METAL HYDRIDE BINDER IMPARTS GREEN STRENGTH OT THE BODY FORMED PRIOR TO SINTERING AND RESULTS IN A SINTERED BODY WITH SMOOTH, STRONG BONDS CONNECTING THE POWDER PARTICLES AND WITH CLEAN, UNCONTAMINATED INTERIOR SURFACES.
摘要:
A method for producing a wear-resistant and corrosion-resistant stainless steel part for a nuclear reactor is provided. This method includes steps of providing a tubular blank in austenitic stainless steel whose carbon content is equal to or lower than 0.03% by weight; shaping the blank; finishing the blank to form the cladding; hardening the outer surface of the cladding by diffusing one or more atomic species; the blank, before the providing step or during the shaping or finishing step, being subjected to at least one hyper quenching with sub-steps of: heating the blank to a sufficient temperature and for a sufficient time to solubilize any precipitates present; quenching the blank at a rate allowing the austenitic structure to be maintained in a metastable state at ambient temperature and free of precipitates.