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CN-121992330-A - Aluminum foil roller with WC coating and preparation method thereof

CN121992330ACN 121992330 ACN121992330 ACN 121992330ACN-121992330-A

Abstract

The invention discloses an aluminum foil roller with a WC coating and a preparation method thereof, and belongs to the technical field of metal material surface engineering. The invention provides a composite coating structure on the surface of a roller matrix, wherein the composite coating structure comprises a transition layer, a gradient layer and a working surface layer from inside to outside, and the structural design greatly improves the bonding strength of the coating and the matrix through pinning effect, micro-metallurgical bonding and gradient transition, optimizes the stress distribution in the coating, ensures that the roller can effectively resist the compressive stress and the shearing stress of an aluminum foil under high rolling force, fundamentally prevents early spalling and abrasion failure of the coating, and remarkably prolongs the service life. Meanwhile, the method provides a reliable remanufacturing way for the failed aluminum foil roller, and has remarkable economic benefit.

Inventors

  • LI YUXI
  • SONG CAN
  • LEI YONG
  • ZHOU WUXI
  • XU ZHAOPING

Assignees

  • 自贡长城表面工程技术有限公司

Dates

Publication Date
20260508
Application Date
20260204

Claims (10)

  1. 1. The aluminum foil roller with the WC coating is characterized by comprising a roller substrate and a working layer attached to the surface of the roller substrate, wherein the working layer is of a composite structure and sequentially comprises a transition layer, a gradient layer and a working surface layer from inside to outside, the transition layer is a metal alloy layer prepared by a high-speed thermal spraying technology and forms an interface of mechanical interlocking and micro-metallurgical bonding with the surface of the roller substrate subjected to roughening treatment, the gradient layer comprises a WC ceramic phase and a metal bonding phase, the proportion of the WC ceramic phase in the gradient layer is gradually increased from inside to outside, and the components of the working surface layer comprise WC hard alloy powder and an auxiliary agent capable of forming micro-metallurgical bonding and pinning effects with the WC hard alloy powder.
  2. 2. The coated WC aluminum foil roller as recited in claim 1, wherein the high-speed thermal spraying technique is supersonic flame spraying, high-speed air-fuel spraying, explosion spraying or overspeed explosion spraying.
  3. 3. The aluminum foil roll with WC coating according to claim 1, wherein the roughening treatment mode of the roll substrate surface is electric spark roughening, laser roughening or plasma roughening.
  4. 4. The aluminum foil roller with the WC coating according to claim 1, wherein the material of the transition layer is NiAl, niCr, niCrAl, niCrAlY or a metal alloy containing at least one of Ti, zr and Hf, and the thickness of the transition layer is 45-55 μm.
  5. 5. The aluminum foil roller with the WC coating according to claim 1, wherein the gradient layer is in transition from 50wt% to 95wt% of the content of the WC ceramic phase from inside to outside, and the thickness of the gradient layer is 50-300 μm.
  6. 6. The coated aluminum foil roll of claim 1 wherein the WC ceramic phase has a particle size of-30/+5 μm.
  7. 7. The roll of WC coated aluminum foil as recited in claim 6, wherein the metallic bond phase is NiAl, niCr, niCrAl, niCrAlY or a metallic alloy containing at least one of Ti, zr and Hf, and the metallic bond phase has a grain size of-45/+15 μm.
  8. 8. The aluminum foil roller with the WC coating according to claim 1, wherein the auxiliary agent is NiAl, niCr, niCrAl, niCrAlY or a metal alloy containing at least one of Ti, zr and Hf, and the auxiliary agent accounts for 0-20% of the mass of the WC hard alloy powder.
  9. 9. The aluminum foil roller with WC coating according to claim 1, wherein the thickness of the working surface layer is 190-210 μm.
  10. 10. The method for preparing the aluminum foil roller with the WC coating as set forth in any one of claims 1 to 9, characterized by comprising the following steps: S1, roughening the surface of a roller matrix; S2, spraying metal alloy powder on the roughened roller matrix surface by adopting a high-speed thermal spraying technology to form a transition layer; s3, spraying a gradient layer on the transition layer by controlling the powder feeding rate of the WC ceramic phase and the metal binding phase; S4, spraying mixed powder containing WC hard alloy powder and auxiliary agent on the gradient layer to form a working surface layer; S5: and (5) finely grinding and polishing the sprayed roller to obtain the product.

Description

Aluminum foil roller with WC coating and preparation method thereof Technical Field The invention belongs to the technical field of metal material surface engineering, and particularly relates to an aluminum foil roller with a WC coating and a preparation method thereof. Background The aluminum foil production process has extremely high performance requirements on the roller, and the roller needs to bear huge shearing force, rolling force, strong friction and adhesion of aluminum materials. Currently, high-performance aluminum foil rollers are mostly surface-strengthened by adopting a WC (tungsten carbide) -based cermet coating with high hardness and high wear resistance. However, conventional WC coating technology faces the following serious challenges when applied to aluminum foil rolls: 1. The bonding strength of the coating and the matrix is insufficient, namely, due to the obvious difference of physical properties (such as thermal expansion coefficient and elastic modulus) of the WC material and the roller matrix (usually high-strength forged steel or cast iron), the interface of the coating is easy to become a source of crack initiation and expansion under the alternating stress and thermal shock generated by high-speed rolling, so that the coating is peeled off. 2. The internal stress is concentrated, the internal structure of the WC coating with a single component is uniform, when the WC coating is subjected to huge compressive stress and shearing stress, the stress cannot be effectively dissipated, and transverse cracks are easily generated in the coating and finally failure occurs. 3. The anti-stripping capability is poor, namely, in aluminum foil rolling, the surface of a roller bears abrasion, and more importantly, huge shear stress caused by high rolling force, which puts extremely high requirements on the anti-stripping capability of the coating. The traditional coating is easy to peel off and lose efficacy in early stage under the working condition, but is in abnormal abrasion and lose efficacy, so that the service life of the roller is greatly shortened. 4. The roller remanufacturing is difficult, if the coating of the roller after failure peels off, the roller can damage the matrix, so that the performance of the repaired coating is difficult to ensure, and the roller can only be scrapped and treated, so that the cost is high. Therefore, the aluminum foil roller WC coating technology which can realize high-strength combination of the coating and the matrix, optimally distribute internal stress, remarkably improve the anti-stripping capability and the wear resistance, and support high-efficiency remanufacturing is developed, and has great engineering application value and economic benefit. Disclosure of Invention Aiming at the prior art, the invention provides an aluminum foil roller with a WC coating and a preparation method thereof, so as to solve the technical problems of insufficient bonding strength between the coating and a matrix and poor anti-stripping capability. In order to achieve the aim, the technical scheme adopted by the invention is that the aluminum foil roller with the WC coating comprises a roller substrate and a working layer attached to the surface of the roller substrate, wherein the working layer is of a composite structure and sequentially comprises a transition layer, a gradient layer and a working surface layer from inside to outside, the transition layer is a metal alloy layer prepared by a high-speed thermal spraying technology and forms an interface of mechanical interlocking and micro-metallurgical bonding with the surface of the roller substrate subjected to roughening treatment, the gradient layer comprises a WC ceramic phase and a metal bonding phase, the proportion of the WC ceramic phase in the gradient layer is gradually increased from inside to outside, and the components of the working surface layer comprise WC hard alloy powder and an auxiliary agent capable of forming micro-metallurgical bonding and pinning effects with the WC hard alloy powder. On the basis of the technical scheme, the invention can be improved as follows. Further, the high-speed thermal spraying technique is supersonic flame spraying, high-speed air fuel spraying, explosion spraying or overspeed explosion spraying. Further, the roughening treatment mode of the surface of the roller matrix is electric spark roughening, laser roughening or plasma roughening. Further, the material of the transition layer is NiAl, niCr, niCrAl, niCrAlY or a metal alloy containing at least one of Ti, zr and Hf, and the thickness of the transition layer is 45-55 mu m. Further, the content of the WC ceramic phase of the gradient layer is changed from 50wt% to 95wt%, and the thickness of the gradient layer is 50-300 mu m. Further, the WC ceramic phase had a particle size of-30/+5 μm. Further, the metal binder phase is NiAl, niCr, niCrAl, niCrAlY or a metal alloy containing at least one of Ti, zr and Hf, and