30results about How to "Low expansion properties" patented technology

Disclosed is a fiber-reinforced composite resin composition which can be used as a sealing agent, an adhesive or a filler, specifically a fiber-reinforced composite resin composition which has low thermal expansion, high strength light weight and high thermal conductivity at such levels that have been required recently, particularly which has a high isotropic thermal conductivity at a satisfactory level. The composition comprises a fiber having an average fiber diameter of 4 to 200 nm. When the composition is cured in a plate-like shape, the cured product has a total light transmittance of 70% or higher per 50 [mu]m thickness as measured at an wavelength of 400 to 700 nm and thermal conductivities both in a thickness-wise direction and a plane-wise direction of 0.4 W / m. K or higher. In the cured product, the fiber is oriented randomly.

Disclosed is a fiber-reinforced composite resin composition which can be used as a sealing agent, an adhesive or a filler, specifically a fiber-reinforced composite resin composition which has low thermal expansion, high strength light weight and high thermal conductivity at such levels that have been required recently, particularly which has a high isotropic thermal conductivity at a satisfactory level. The composition comprises a fiber having an average fiber diameter of 4 to 200 nm. When the composition is cured in a plate-like shape, the cured product has a total light transmittance of 70% or higher per 50 [mu]m thickness as measured at an wavelength of 400 to 700 nm and thermal conductivities both in a thickness-wise direction and a plane-wise direction of 0.4 W / m. K or higher. In the cured product, the fiber is oriented randomly.

The invention relates to a heat-conducting polymer-base composite material and a preparation method thereof. The invention aims to solve the problems of high cost of the existing preparation method and poor heat conductivity of the obtained polymer-base composite material. The product is composed of a through-hole-bearing composite material plate, a filling material filled in the through hole of the through-hole-bearing composite material plate, film material layers positioned on the upper and lower surfaces of the through-hole-bearing composite material plate, and adhesive layers for bonding the film materials and the through-hole-bearing composite material plate. The method comprises the following steps: 1. preparing the through-hole-bearing composite material plate; 2. preparing a precuring plate; 3. preparing the composite plate; 4.preparing the cleaned composite plate; and 5. preparing the heat-conducting polymer-base composite material. The heat conductivity coefficient of the heat-conducting polymer-base composite material can reach 200-250 W / (m.K).

The invention provides a method for preparing a copper-based composite material. The preparation method includes the following steps: providing copper powder, zirconium tungstate powder and barium strontium titanate powder, and mixing the copper powder, zirconium tungstate powder and barium strontium titanate powder , to obtain the first mixed powder; utilize the method of dry ball milling to carry out ball milling to the first mixed powder, obtain the second mixed powder; carry out the first reduction heat treatment to the second mixed powder, obtain the third mixed powder; carry out the third mixed powder cold isostatic pressing to obtain the first block; hot pressing and sintering the first block to obtain the second block; and rolling the second block. The dry powder mixing process is used, thus improving the powder mixing efficiency and improving the powder mixing effect; the invention specially designs the reduction process, so that the oxidized powder in the powder mixing process can be accurately restored to the original state, and will not be reduced The oxide powder itself will not cause the oxygen content in the oxide to deviate from the ideal value, and the ordinary hot pressing sintering method is used, the technology is simple and mature, and the cost is low.

The invention belongs to the field of precision alloy, and particularly relates to a low-expansion magnetic shielding alloy for an optical fiber loop skeleton, and a preparation method thereof. The alloy comprises the following chemical components in percentage by weight: 32.0-35.2% of Ni, 3.0-3.5% of Co, 0.10-0.25% of Mn, less than or equal to 0.15% of Si, less than or equal to 0.02% of Cu, less than or equal to 0.01% of C, less than or equal to 0.01% of P, less than or equal to 0.01% of S, and the balance of Fe. The preparation method of the low-expansion magnetic shielding alloy comprises the following steps sequentially: preparation of high-purity raw materials, proportioning of ingredients, smelting of a vacuum induction furnace and vacuum arc remelting, forging and processing, sampling, thermal treatment, and performance test. The thermal treatment system comprises the steps of under protection of high-purity hydrogen gas, carrying out furnace heating to 970+ / -10DEG C, preserving heat for 2.5-3h, cooling to 550+ / -10DEG C at the speed of 200-250DEG C / h, rapidly cooling to 300DEG C below for discharging. Compared with the existing low-expansion alloy 4J32 and on the premise that low-expansion characteristic is kept, the low-expansion magnetic shielding alloy has high initial magnetic conductivity, integrates the two advantages of low expansion property and high magnetic shielding property, namely within the temperature range of -45DEG C to 75DEG C, the expansion coefficient of the alloy is 1.0*10<-6> / DEG C below; the initial magnetic conductivity is higher than 1.5mH / m.