CN-121583426-B - Metal lattice structure with customizable thermal expansion coefficient and design method thereof

CN121583426BCN 121583426 BCN121583426 BCN 121583426BCN-121583426-B

Abstract

The invention relates to the technical field of aviation materials, and discloses a metal lattice structure with a customizable thermal expansion coefficient and a design method thereof, each lattice unit of the lattice structure is an isosceles triangle formed by two waist elements and a bottom element, and each element is formed by a diamond frame and a diagonal line. Each element consists of two metal materials, the diamond frame is made of one metal material, the diagonal line is made of the other metal material, and the length proportion of the edges and the diagonal line of the diamond frame of the element and the material type can be adjusted to enable the lattice unit to have the characteristic that one of the negative thermal expansion coefficient, the zero thermal expansion coefficient, the positive thermal expansion coefficient or the thermal expansion coefficient mutation occurs near the Curie temperature point of the low expansion alloy of the abnormal thermal expansion phenomenon, so that the customizable requirement of the thermal expansion of the metal lattice structure is met.

Inventors

FU YU
LI ZUOJUN
TIAN WEI
ZHANG SHAOPING
ZHANG DONGZHE
ZHANG WANGYANG
LIU YANFEI

Assignees

中国航发四川燃气涡轮研究院

Dates

Publication Date: 20260505
Application Date: 20260123

Claims (8)

1. A metal lattice structure with a customizable thermal expansion coefficient is characterized by comprising a plurality of lattice unit cells which are periodically arranged in space, wherein each lattice unit cell is formed by fixedly connecting two waist unit cells and a bottom unit cell to form an isosceles triangle; Each elementary is composed of two metal materials, wherein each side of the rhombus frame of the waist elementary and each diagonal of the bottom elementary are made of one metal material, and each side of the rhombus frame of the waist elementary and each diagonal of the bottom elementary are made of the other metal material.
2. The metal lattice structure of claim 1, wherein the diamond frames of the lattice unit cells of the lattice structure are of a first metal material and the diagonals of the waist cells are of a second metal material, and the diamond frames of the bottom cells are of the second metal material and the diagonals of the bottom cells are of the first metal material, and the coefficient of thermal expansion of the first metal material is less than the coefficient of thermal expansion of the second metal material over the same temperature range.
3. The metal lattice structure of claim 1, wherein the diamond frames of the lattice unit cells of the lattice structure are of a second metal material, the diagonals of the waist cells are of a first metal material, the diamond frames of the bottom cells are of the first metal material, the diagonals of the bottom cells are of a second metal material, and the coefficient of thermal expansion of the first metal material is less than the coefficient of thermal expansion of the second metal material over the same temperature range.
4. A metal lattice structure according to claim 2 or 3, wherein the coefficient of thermal expansion of the second metal material is more than 1.5 times that of the first metal material.
5. A metal lattice structure according to claim 2 or 3, wherein the first metal material comprises one of titanium alloy, invar alloy, low expansion superalloy, and the second metal material comprises one of aluminum alloy, stainless steel, nickel-based superalloy, cobalt-based superalloy.
6. The metal lattice structure of claim 1, wherein three elements in an isosceles triangle are connected by welding, pinning, bolting or mortise and tenon embedding.
7. A method of designing a metal lattice structure having a customizable thermal expansion coefficient for achieving the metal lattice structure of any one of claims 1-6, comprising: Constructing analysis models between the thermal expansion coefficients of the metal materials of the diagonals of the waist primitive and the bottom primitive, and the thermal expansion coefficients of the diamond frames and the corresponding diagonal dimension parameters of the waist primitive and the bottom primitive and the thermal expansion coefficients of the lattice unit along the normal direction of the bottom primitive of the isosceles triangle; according to the thermal expansion coefficients of the selected metal materials of the rhombus frames and the bottom base elements, the thermal expansion coefficients of the metal materials of the rhombus frames and the bottom base elements are analyzed by adopting the analysis model to obtain the combination of the rhombus frames and the corresponding diagonal dimension parameters of the rhombus frames and the bottom base elements which meet the target thermal expansion coefficients of the metal lattice structure.
8. The method of claim 7, wherein the analytical model constructed is Wherein Is the thermal expansion coefficient of lattice unit cells along the normal direction of the base element of the isosceles triangle, Is the thermal expansion coefficient of the metal material of the rhombus frame of the waist element and the diagonal line of the bottom element, Is the thermal expansion coefficient of the metal material of the rhombus frame of the diagonal line and the bottom line of the waist element, Is the side length of the rhombus frame of the waist primitive, The diagonal line of the waist element is long, The side length of the base element diamond frame, The bottom primitive is diagonally long.

Description

Metal lattice structure with customizable thermal expansion coefficient and design method thereof Technical Field The invention relates to the technical field of aviation materials, and discloses a metal lattice structure with a customizable thermal expansion coefficient and a design method thereof. Background The thermal expansion coefficient is used as a physical quantity for quantifying the thermal deformation behavior of a material and is used for measuring the change degree of the volume and shape of the material/structure caused by the change of the external temperature. Traditional metallic materials have physical properties of thermal expansion and contraction. When two materials with different thermal expansion are combined (heterogeneous material structure), serious thermal stress concentration is caused by thermal mismatch, and particularly in the aerospace field, the original structural precision of the high-precision heterogeneous material structure is damaged by thermal deformation caused by temperature change. The clearance control member is widely used in the field of aeroengines to control rotor-stator clearances, such as rotor blades and outer rings/cases, and comb teeth and honeycomb inner rings. In an aeroengine, the rotor-stator clearance of the clearance control member is a critical parameter, which has a very important influence on the performance and safety of the engine. The reduced clearance benefits engine performance, increases engine efficiency, and reduces fuel consumption, while too small a clearance increases the risk of contact between components, which can lead to wear, overheating, and even failure. The design of the radial clearance of the advanced aeroengine clearance control component is to consider both performance and safety, and the final design aim is to keep the radial clearance to be minimum under all working conditions of the engine, and the radial clearance is not subjected to serious rub under the conventional flight condition. In practical applications, it is desirable to have a large negative thermal expansion coefficient, a large positive thermal expansion coefficient, or a zero thermal expansion coefficient. However, at present, research on customizable thermal expansion lattices is mainly focused on expanding the thermal expansion coefficient, and most of the lattices have isotropic thermal expansion coefficients, or have large negative thermal expansion coefficients or large positive thermal expansion coefficients in a single direction, so that large thermal expansion range changes, particularly abrupt changes of the thermal expansion coefficients, cannot be realized. Disclosure of Invention The invention aims to provide a metal lattice structure with a customizable thermal expansion coefficient and a design method thereof, which can meet the customizable thermal expansion requirement of the metal lattice structure. In order to achieve the technical effects, the technical scheme adopted by the invention is as follows: The metal lattice structure with the customizable thermal expansion coefficient is formed by periodically arranging a plurality of lattice unit cells in space, wherein each lattice unit cell is formed by fixedly connecting two waist unit cells and one bottom unit cell to form an isosceles triangle; Each elementary is composed of two metal materials, wherein each side of the rhombus frame of the waist elementary and each diagonal of the bottom elementary are made of one metal material, and each side of the rhombus frame of the waist elementary and each diagonal of the bottom elementary are made of the other metal material. Further, the diamond-shaped frame of the lattice unit waist element of the lattice structure is made of a first metal material, the diagonal line of the waist element is made of a second metal material, the diamond-shaped frame of the bottom element is made of a second metal material, the diagonal line of the bottom element is made of a first metal material, and the thermal expansion coefficient of the first metal material is smaller than that of the second metal material in the same temperature range. Further, the diamond-shaped frame of the lattice unit waist element of the lattice structure is made of a second metal material, the diagonal line of the waist element is made of a first metal material, the diamond-shaped frame of the bottom element is made of a first metal material, the diagonal line of the bottom element is made of a second metal material, and the thermal expansion coefficient of the first metal material is smaller than that of the second metal material in the same temperature range. Further, the thermal expansion coefficient of the second metal material is 1.5 times or more the thermal expansion coefficient of the first metal material. Further, the first metal material comprises one of a titanium alloy, an invar alloy and a low expansion superalloy, and the second metal material comprises one of an aluminu