A high-speed machining tool made of a steel-bonded carbide and a method for preparing the same relate to the technical field of lathe tools made of steel-bonded carbides, and overcome the problems of traditional steel-bonded carbide lathe tools about low hardness and low toughness. The high-speed machining tool includes a skeleton, a main body, and a coating. The main body is consolidated by the skeleton from inside. The skeleton and the main body are both ringlike in shape. The main body has its outer surface covered by the coating. The high-speed machining tool is such made that the skeleton is hard and the main body is tough. The blade of the tool is hard and can transfer vibrations to the main body, thereby protecting the tool from brittle fractures and improving the overall performance of the tool.

The present disclosure discloses a method for coating a magnetic powder core with sodium silicate, including: using polyoxyethylene laurylether phosphate as a dispersant for sodium silicate and lignosulfonate as a dispersant for a metal magnetic powder, mixing a dispersed sodium silicate solution and a dispersed metal magnetic powder, coating the dispersed metal magnetic powder, and drying: adding an insulating adhesive and a lubricant, subjecting the resulting mixture to a compression molding, and finally, carrying out a high-temperature annealing treatment to obtain a sodium silicate coated magnetic powder core.

A sintered friction material is formed by pressure sintering mixed powder at 800° C. or above, the mixed powder consisting of, in mass %, Cu and/or Cu alloy: 40.0 to 80.0%, Ni: 0% or more and less than 5.0%, Sn: 0 to 10.0%, Zn: 0 to 10.0%, VC: 0.5 to 5.0%, Fe and/or Fe alloy: 2.0 to 40.0%, lubricant: 5.0 to 30.0%, metal oxide and/or metal nitride: 1.5 to 30.0%, and the balance being impurity.

A material of formula Li.sub.aTi.sub.b(A.sub.xS.sub.3-x).sub.c wherein A is a metalloid element chosen from selenium, tellurium and mixtures thereof, and the stoichiometric coefficients a, b, c and x are such that 0<x<2.2; 0.4≤a≤4.5; 0.9≤b≤1.1; and 0.9≤c≤1.1.

A titanium aluminide (TiAl) coating capable of improving high-temperature oxidation resistance of titanium alloys and a preparation method thereof are provided. The TiAl coating includes α-AlF.sub.3 nanoparticles, and a content of the α-AlF.sub.3 nanoparticles is 5-30 vol. % of the TiAl coating. The preparation method of the TiAl coating includes: using a TiAl alloy target and an α-AlF.sub.3 target as raw materials, and performing magnetron sputtering on a substrate surface to prepare a coating; the magnetron sputtering is double-target co-sputtering, and a substrate temperature during the magnetron sputtering is 150° C., the TiAl alloy target is performed direct current sputtering with a power of 0.5-2 kW, and the α-AlF.sub.3 target is performed radio frequency sputtering with a power of 0.07-0.2 kW. After the coating is obtained by the double-target co-sputtering, the obtained coating is heat-treated at 600-800° C. for 5-20 h to obtain a final coating.

A sintering composition, consisting essentially of: a solvent; and a metal complex dissolved in the solvent, wherein: the sintering composition contains at least 60 wt. % of the metal complex, based on the total weight of the sintering composition; and the sintering composition contains at least 20 wt. % of the metal of the metal complex, based on the total weight of the sintering composition.

A copper paste for joining contains metal particles and a dispersion medium, in which the copper paste for joining contains copper particles as the metal particles, and the copper paste for joining contains dihydroterpineol as the dispersion medium. A method for manufacturing a joined body is a method for manufacturing a joined body which includes a first member, a second member, and a joining portion that joins the first member and the second member, the method including: a first step of printing the above-described copper paste for joining to at least one joining surface of the first member and the second member to prepare a laminate having a laminate structure in which the first member, the copper paste for joining, and the second member are laminated in this order; and a second step of sintering the copper paste for joining of the laminate.

A method of manufacturing a composite material for thermal shields, and a composite material manufactured by the method are proposed. The method may include preparing a mixed powder including (i) a metal powder including a powder of aluminum or aluminum alloy and (ii) a polymer or ceramic powder. The method may also include sintering the mixed powder through pressureless sintering or spark plasma sintering to produce a composite material. According to the present disclosure, a powder of polymer, ceramic, and/or metal which have a relatively low level of thermal conductivity can be compounded with a metal material including aluminum through a sintering process of powder metallurgy, such as pressureless sintering or spark plasma sintering. Thus, a heterogeneous composite material with a low-level thermal conductivity (10 W/mk or less) can be obtained, and the composite material can be used as a material for various thermal shields.

A method for manufacturing a functionally graded composite material for a printed circuit board (PCB) is proposed. The method may include preparing two or more types of mixed powders with different contents of polymer or ceramic powder, each mixed powder comprising (i) a metal powder comprising a powder made of aluminum or an aluminum alloy and a powder of magnesium and (ii) the polymer or ceramic powder. The method may also include laminating the two or more types of mixed powders to form a functionally graded laminate in which a ratio of the content of the polymer or ceramic powder to the content of the metal powder in each of layers stacked in sequence from bottom to the top of the laminate differs. The method may further include preparing a functionally graded composite material by sintering the functionally graded laminate by pressureless sintering or spark plasma sintering.

The present invention discloses rare earth-bonded magnetic powder and a preparation method therefor. The bonded magnetic powder is of a multilayer core-shell structure, and comprises a core layer and an antioxidant layer (3), wherein the core layer is formed by RFeMB, R is Nd and/or PrNd, and M is one or more of Co, Nb, and Zr; and the core layer is coated with an iron-nitrogen layer (2). In addition, the present invention also discloses the preparation method for the rare earth-bonded magnetic powder and a bonded magnet. The oxidation and corrosion of magnetic raw powder during phosphorization and subsequent treatment process are effectively prevented, thereby further improving the long-term temperature resistance and environmental tolerance of the material.