Central South University

Other

Boyun Huang

Zuming Liu

Quan Li

Xueqian Lv

Kai Peng

Fan Zhao

Qizhong Huang

Mengmei Ma

Zhean Su

Mingyu Zhang

Pengfei Su

Yang Guo

Jianxun Chen

Shiqi Chen

Qinglong Duan

Zhiyong Xie

A preparation method for an iron-based alloy powder EBSD test sample includes the following steps: surface electrolytic activation of an iron-based powder; ultrasonically cleaning the powder, and drying the powder to obtain a surface activated powder; adding the surface activated powder to a chemical embedding solution for ultrasonic dispersion; after the ultrasonic dispersion, performing a plating process; then heating to 80-92° C. for chemical reaction to prepare an iron-based alloy bulk which coated with nickel. The plating process is as follows: still standing, stirring, and repeating the still standing is taken as a cycle, and at least one cycle is performed to complete the plating process. Then grinding and electropolishing are done to the obtained iron-based alloy bulk coated with nickel to obtain the iron-based alloy powder EBSD test sample.

Preparation method for iron-based alloy powder EBSD test sample

A multi-scale and multi-phase dispersion strengthened iron-based alloy, and preparation and characterization methods thereof are provided. The alloy contains a matrix and a strengthening phase. The strengthening phase includes at least two types of the strengthening phase particles with different sizes. A volume of the two types of the strengthening phase particles with different sizes having a particle size less than or equal to 50 nm accounts for 85-95% of a total volume of all the strengthening phase particles. The matrix is a Fe&#x2014;Cr&#x2014;W&#x2014;Ti alloy. The strengthening phases include crystalline YOphase, Y&#x2014;Ti&#x2014;O phase, Y&#x2014;Cr&#x2014;O phase, and Y&#x2014;W&#x2014;O phase. The characterization method comprises electrolytically separating the strengthening phases in the alloy, and then characterizing by using an electron microscope. The tensile strength of the prepared alloy is more than 1600 MPa at room temperature, and is more than 600 MPa at 700&#xb0; C.

Multi-scale and multi-phase dispersion strengthened iron-based alloy, and preparation and characterization methods thereof

An oxide dispersion-strengthened (ODS) iron-based alloy powder and a characterization method thereof are provided. The alloy powder comprises a matrix and strengthening phases. The strengthening phases include at least two types of strengthening phase particles with different sizes, wherein a volume of the particles with a particle size of less than or equal to 50 nm accounts for 85-95% of a total volume of all the strengthening phase particles. The matrix is a Fe&#x2014;Cr&#x2014;W&#x2014;Ti alloy. The characterization method of the ODS iron-based alloy powder comprises separating the strengthening phases from the powder matrix through electrolysis, and analyzing and characterizing the strengthening phases using an electron microscope.

Oxide dispersion-strengthened iron-based alloy powder and characterization method thereof

The invention relates to a method for eliminating hollow defects in atomized superalloy powder, and pertains to the field of powder metallurgy materials. A ball-milling processing is conducted on the atomized alloy powder to eliminate the hollow defect, obtain solid powder and increase powder utilization efficiency. By controlling mill ball diameters, mass ratio of mill balls with different diameters, mass ratio of ball to powder and ball milling time, a multi-directional impact on the powder is achieved, thereby control powder shape and obtain solid spherical powder. The invention eliminates powder hollow defect by using ball milling process and equipment. This invention with high powder utilization efficiency, short ball milling time and simple operating process, can be used for large-scale preparation and application.

Method for eliminating hollow defect in atomized alloy powder

A method for producing carbon paper, including: 1) employing a polyacrylonitrile-based carbon fiber as a reinforcing material, a phenolic resin or epoxy resin as a bonding agent, and molding and preparing the carbon fiber into a carbon fiber blank by a dry paper-making method; and 2) stacking and putting a product obtained in step 1) into a reaction furnace for deposition process, the pressure in the reaction furnace being 1 kPa to 1 atmosphere, with methane, propene, or liquefied petroleum gas as a carbon source gas, nitrogen or argon gas as a diluent gas, the concentration of the carbon source gas being 5-100%, the gas flow rate being 0.1-5 L/min, and the temperature in the reaction furnace being controlled at between 800&#xb0; C. and 1100&#xb0; C., and the time of deposition process being 1-5 h.

Method and device for producing carbon paper

Growing community of inventors

Hunan, China

Boyun Huang