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CN-121972670-A - Aluminum-based powder fuel with crystal boundary oxygen vacancy channel and preparation method and application thereof

CN121972670ACN 121972670 ACN121972670 ACN 121972670ACN-121972670-A

Abstract

The invention discloses an aluminum-based powder fuel with a crystal boundary oxygen vacancy channel, a preparation method and application thereof, and particularly relates to the technical field of metal fuel and aluminum-based alloy powder fuel. The method comprises the steps of heating and melting pure aluminum to form an aluminum melt, adding an Al-RE intermediate alloy into the aluminum melt, adjusting the total content of rare earth elements RE in the melt to be 0.1-7 wt%, and finally carrying out controlled supersonic atomization and rapid solidification on the melt after uniform mixing to obtain aluminum-based alloy powder. The invention constructs rare earth oxide channel rich in oxygen vacancy defect at grain boundary after powder combustion, and further promotes oxidation combustion. The lattice distortion caused by the atomic radius difference of the double rare earth (Ce/La) and the in-situ solid solution of boron atoms are utilized, so that the formation energy of oxygen vacancies is greatly reduced. The high-concentration oxygen vacancies form a high-speed oxygen transmission channel in the combustion process, the obstruction of a compact oxide film is broken, so that oxygen can quickly permeate into the particle core, and the burnout rate and the energy release efficiency of aluminum powder are remarkably improved.

Inventors

  • Mineyama
  • Wu Lijihexige
  • XINBAYAER
  • BAOYINHEXI

Assignees

  • 内蒙古工业大学

Dates

Publication Date
20260505
Application Date
20260407

Claims (8)

  1. 1. A method of preparing an aluminum-based powder fuel having grain boundary oxygen vacancy channels, the method comprising: heating and melting pure aluminum to form an aluminum melt; Adding an Al-RE intermediate alloy into the aluminum melt, and regulating the total content of rare earth RE in the melt to be 0.1-7wt%, wherein the rare earth RE comprises a first rare earth element and a second rare earth element, the first rare earth element is one or more of Ce, pr and Tb, and the second rare earth element is one or more of La, nd, sm, gd, Y, sc, dy, er; Step three, carrying out controlled supersonic atomization and rapid solidification on the melt after uniform mixing to obtain aluminum-based alloy powder; the controlled supersonic speed atomization rapid solidification in the step three is to lead the Al-RE intermetallic compound phase to be separated out at the grain boundary of the powder solidification structure and form a three-dimensional distribution network structure extending along the grain boundary by regulating the supercooling degree and the cooling rate of an atomization medium, and simultaneously introduce non-equilibrium state lattice distortion into the Al-RE intermetallic compound phase and the adjacent grain boundary area thereof; The non-equilibrium lattice distortion is configured to induce, during subsequent combustion oxidation, a rare earth oxide phase having an intrinsic concentration of oxygen vacancy defects above its thermodynamic equilibrium state, thereby forming diffusion channels enriched in oxygen vacancy defects.
  2. 2. The preparation method according to claim 1, wherein the content of the first rare earth element is 0.05 to 4wt% and the content of the second rare earth element is 0.01 to 4wt%.
  3. 3. The method of claim 1, wherein the B source is an Al-B master alloy.
  4. 4. The method according to claim 1, wherein in the third step, the process parameter of controlled supersonic atomization and rapid solidification is an atomization medium of argon, nitrogen or a mixture thereof, the atomization pressure is 3-8MPa, and the superheating temperature of the melt is controlled to be 50-150 ℃ above the liquidus line, so as to achieve a local cooling rate of 10 4 -10 6 K/s.
  5. 5. The aluminum-based powder fuel with the crystal boundary oxygen vacancy channel is characterized by comprising an aluminum matrix and a three-dimensional Al-RE intermetallic compound phase network distributed at a crystal boundary, wherein the intermetallic compound at the crystal boundary is oxidized and combusted to form the structural characteristic of being rich in oxygen vacancy defects, and the Al-RE intermetallic compound simultaneously contains a first rare earth element and a second rare earth element, and the first rare earth element and the second rare earth element show a co-enrichment characteristic in the crystal boundary region.
  6. 6. The aluminum-based powder fuel with grain boundary oxygen vacancy channels of claim 5, wherein the three-dimensional network of Al-RE intermetallic compound phases is in-situ coupled with B element, and the Al-RE phase is an Al-RE-B ternary transition layer with a width of 1-50nm at the interface of the aluminum matrix, or an Al-RE-B ternary transition layer is formed at the interface of the Al-RE phase and the aluminum matrix.
  7. 7. The aluminum-based powder fuel with grain boundary oxygen vacancy channels of claim 6, wherein the Al-RE intermetallic compound phase is mainly Al 11 (first rare earth element, second rare earth element) 3 solid solution phase, local distortion of lattice fringes exists, lattice strain value epsilon is >0.5%, and boron element is enriched in the distortion region.
  8. 8. Use of an aluminium-based powder fuel having grain boundary oxygen vacancy channels in an additive or energy component of a solid propellant, explosive, pyrotechnic or metal fuel.

Description

Aluminum-based powder fuel with crystal boundary oxygen vacancy channel and preparation method and application thereof Technical Field The invention relates to the technical field of metal fuel and aluminum-based alloy powder fuel, in particular to an aluminum-based powder fuel with a crystal boundary oxygen vacancy channel, and a preparation method and application thereof. Background Aluminum powder is widely applied to solid rocket propellants, explosives and other energetic material systems because of the advantages of high volume energy density, good storage stability, environmental friendliness of combustion products and the like. However, the conventional micron-sized aluminum powder has a remarkable defect in practical application that a dense and high-melting-point aluminum oxide (Al 2O3) film is extremely easy to form on the surface of particles in the combustion or oxidation process. The 'core-shell' structure seriously prevents the diffusion of external oxygen into the particles and the transmission of internal heat to the surfaces, so that the reaction front is difficult to effectively advance to the core of the particles, thereby causing the problems of ignition delay, incomplete combustion, high residue rate, large two-phase flow loss and the like, and greatly limiting the full play of the energy efficiency of the aluminum-based fuel. The prior art generally improves the combustion performance of aluminum powder by refining the particle size of the powder, introducing a catalyst or performing surface coating modification on the aluminum powder. However, the simple dependence on particle size refinement brings about the problems of safety and cost, and the added catalyst or surface coating has the defects of weak interfacial binding force, easy flaking after being heated, difficult formation of continuous action channels in the particles, and the like. Chinese patent CN119614259a discloses an aluminum lithium alloy powder fuel, which is prepared by adding Li (2-10%), mg (0.1-5%) and rare earth elements (RE, 0.1-3%), and by assisting with heat treatment to regulate the distribution of precipitated phases such as Al3 (Li, RE), and aims to utilize the "micro-explosion" characteristic of lithium to break up aluminum particles in situ to promote combustion. However, li is extremely active in chemical property, has strict requirements on preparation, storage and use environments, has higher safety risks, and the micro-explosion effect belongs to a physical crushing mechanism, and has limited improvement of combustion thoroughness due to the lack of an effective oxygen internal diffusion path for a particle area where micro-explosion does not occur. Another more promising technical route is to construct grain boundary diffusion channels. Chinese patent CN119977737a proposes an Al-RE rare earth alloy powder fuel in which oxygen diffusion channels are formed at grain boundaries. According to the technology, rare earth intermediate alloy (such as Al-Ce) is added into pure aluminum, and supersonic atomization and unbalanced solidification are carried out, so that rare earth intermetallic compounds (such as Al 11Ce3) are separated out at a crystal boundary to form a three-dimensional network structure. During combustion, al 11Ce3 at the grain boundaries preferentially oxidizes, producing loose rare earth oxides (such as CeO 2), thereby establishing physical oxygen diffusion channels from the particle surface to the core. Compared with the traditional aluminum powder and micro-explosion alloy, the technology realizes the directional internal diffusion of oxygen through structural design, and the combustion efficiency is obviously improved. However, the oxygen transport mechanism of this technology relies mainly on the macroscopic "loose structure" of rare earth oxides and the intrinsic vacancies in the crystal structure, and there is no targeted design for how to further regulate the defect type and concentration (e.g., oxygen vacancies) within the channel from the atomic scale to enhance the diffusion kinetics of oxygen. In addition, a single rare earth oxide channel has a ceiling in heat release intensity, and if high-enthalpy components are introduced to release heat cooperatively while maintaining high-efficiency oxygen transmission, the dual enhancement of transmission-heat release is expected to be realized, and the energy release efficiency and burnout rate are further improved. Therefore, development of a novel aluminum-based powder fuel which can construct a stable three-dimensional network structure at a grain boundary, form a high-efficiency diffusion channel rich in active defects such as oxygen vacancies and the like in situ in the combustion process, and simultaneously can introduce high-enthalpy components to realize synergistic effect, thereby fundamentally solving the problem of incomplete combustion of the traditional aluminum powder and meeting urgent requirements of high-performance prop