A carbon nanotube (CNT) / metal nanocomposite powder production method for use in additive manufacturing and thermal spraying processes

Abstract

The invention relates to the production method of a carbon nanotube (CNT) / metal nanocomposite powder for use in additive manufacturing and thermal spraying processes. In the method of the invention, composite powders are produced that enable the combined use of CNTs and metal powders with very different densities and enable the production of nanocomposite structures by depositing CNTs on metal powders.

Description

[0001] A CARBON NANOTUBE (CNT) / METAL NANOCOMPOSITE POWDER PRODUCTION METHOD FOR USE IN ADDITIVE MANUFACTURING AND THERMAL SPRAYING PROCESSES

[0002] Technical Field of the Invention

[0003] The invention relates to the production method of a carbon nanotube (CNT) / metal nanocomposite powder for use in additive manufacturing and thermal spraying processes. The CNT / metal nanocomposite powder that is the subject of the invention has the potential to be used in additive manufacturing sectors in parts production, especially in the machinery and aviation industry, and in thermal surface coating processes.

[0004] State of the Art

[0005] Composites are a new group of materials that comprise at least two different material groups called matrix phase and reinforcement phase, and do not dissolve in each other in appropriate combinations in order to strengthen the properties for the purpose of use

[0001] . Today, in addition to traditional methods, composite production is also being developed with new and unconventional production techniques. Composite product printing with a three-dimensional printer technique known as additive manufacturing is one of these new composite production techniques. Additive manufacturing is a production technology the use of which in the industrial sector is rapidly increasing day by day. Additive manufacturing methods are used in cases where a small number of parts are required in composite production, when a design change is made in the part, or when a prototype of a new part needs to be produced. Additive manufacturing, unlike traditional production methods, is a production process based on creating layers directly from the material layer. This manufacturing method allows the production of complex shaped parts by creating minimum waste material due to layered production.

[0006] In the state of the art, CNT-based metal nanocomposite production is a known practice. The vast majority of these applications are carried out by sintering CNT particles together with reinforcement metal powders and / or adding them to a molten metal. Casting methods are methods that can only be economically produced in high quantities due to the cost of metal moulds to be used for part production. Therefore, the production of metal nanocomposite parts comprising CNTs by casting methods, the use of moulds and the high mould production costs are the problems that limit the use of these methods. In addition, the fact that CNTs are not mixed homogeneously into the structure is another important disadvantage in these methods. In addition, making a change in the design after the mould is produced is both costly and very difficult. This situation causes the manufacturing process to become difficult, the manufacturability of the part to decrease and the economic cost to increase.

[0007] In the sintering method, which is another prior art, expensive and difficult to change metallic moulds are needed to produce the nanocomposite part. In case these expensive metallic moulds are used, the number of parts to be produced must be high in order to reduce the production costs. Similar to the casting method, in the sintering process, making a change in the design after the mould is produced is generally not possible and is very costly.

[0008] In another prior art, composite production is carried out by forming carbon nanotubes (CNTs) on fibres with the chemical vapour deposition (CVD) method [2, 3]. However, this method is a method with both high initial investment cost and production cost, and these high production costs restrict the use of composites produced with this method in the industrial field.

[0009] In addition, when CNTs are directly mixed with a metal powder and sprayed onto a surface in the production of nanocomposite materials, the CNTs with very low density are separated and do not accumulate on the surface. For this reason, it is not possible to use CNTs and metal powders together in thermal spraying processes and to produce a coating layer with these methods. In addition, the formation of a coating layer containing CNTs is difficult due to the difficulty of activating CNTs in thermal processes and the fragility of CNTs.

[0010] Due to the limitations and inadequacies of the solutions in the state of the art, the difficulty of changing the metallic moulds used in the production of nanocomposites comprising CNTs, the problem that making a change in the design after the mould is produced being both costly and difficult, and the difficulty of producing CNTs in coating processes due to their low density and fragility, it has become necessary to make a development in this field.

[0011] Brief Description and Aims of the Invention

[0012] The invention relates to the production method of a (CNT) / metal nanocomposite powder for use in additive manufacturing and thermal spraying processes.

[0013] One aim of the invention is to create a nanocomposite powder that will provide economical production of nanocomposite parts. The CNT / metal nanocomposite powder produced with the method that is the subject of the invention is both used in coating methods as a coating material and reduces the production of nanocomposite parts with desired shapes with 3D printers in additive manufacturing to much more affordable costs. Thus, the need for moulds is eliminated and the initial investment cost is reduced. Therefore, the economical production of nanocomposite parts is provided.

[0014] Another aim of the invention is to provide a material with homogeneous distribution in additive manufacturing methods. With the method that is the subject of the invention, CNT / metal nanocomposite powder material that enables the presence of metal powders and CNTs together, enables the production of parts with desired properties with homogeneous distribution and is economically affordable.

[0015] Another aim of the invention is to develop a powder material that will enable the coating of the surface of any part in composite part production by spraying methods without the need for any mould. In the method of the invention, CNTs, which cannot be sprayed together with a metal powder due to their low density, are deposited on a metal powder and made usable in coating processes. In this way, the surface of any part can be coated with spraying methods.

[0016] It is aimed that this CNT / metal nanocomposite powder that is the subject of the invention is used in additive manufacturing and thermal spraying processes to reduce the production cost of composite parts and eliminate the need for mould use. Detailed Description of the Invention

[0017] The invention relates to the production method of a (CNT) / metal nanocomposite powder for use in additive manufacturing and spraying processes. The production of said CNT / metal nanocomposite powder allows the parts needed especially in advanced technology applications to be produced very easily and much more cheaply.

[0018] The production method of the carbon nanotube (CNT) / metal nanocomposite powder, which is the subject of the invention, comprises the process steps of: i. mixing carbon nanotubes (CNT) and metallic powders in polyvinyl alcohol (PVA) and pure water, ii. mixing metal powders and CNTs in an ultrasonic mixer to ensure a homogeneous mixture, and iii. producing nano-sized composite powder from carbon nanotube and metal powder by spray drying method.

[0019] Different metal powders can be used in said method, as well as different ratios of metal powders, PVA, CNT and pure water can be used. The fact that these parameters can be applied in different ratios allows the composite powder to have superior properties for the purpose.

[0020] The CNT / metal nanocomposite powder produced with the method that is the subject of the invention eliminates the use of moulds in composite part production, reducing production to much more affordable costs. The present invention provides a composite powder material production method that requires very low initial investments and has very low production costs. Therefore, the economical production of nanocomposite parts is also provided. With the method that is the subject of the invention, many advantages such as high strength provided by CNTs, high damping of electromagnetic waves, and very good electrical and thermal conductivity in different materials are provided. In said method, by placing CNTs in metallic materials which are more ductile than itself, both their density is increased and the use of CNTs and metal materials together in spraying processes is ensured. In the method that is the subject of the invention, composite powder production is carried out not only in the production of parts but also for use in various coating and additive manufacturing processes in order to obtain a composite structure on the surfaces of the parts. Since CNTs have a very low density, they usually separate spontaneously in any mixture and a homogeneous distribution cannot be obtained. For this reason, with said method, CNTs are distributed homogeneously and accumulated on all metal particles. Another factor that prevents CNTs from being distributed homogeneously is that CNTs accumulate and clump among themselves because their length / diameter ratio is very large. Therefore, accumulation on metal powders cannot be sufficiently achieved. This problem is also solved by vibrating CNTs with an ultrasonic mixer, preventing clumping, and ensuring homogeneous distribution on metal powders. In said method, polyvinyl alcohol acts as a polymer-based organic binder, after binding the CNT and metal powder together, it is dried with hot air, evaporated and removed from the environment. Thus, the CNT and metal powders are kept together and a ready-made nanocomposite powder is obtained for use in additive manufacturing and other methods. With the present invention, it is possible to obtain CNT-containing nanocomposite powders in a very simple and environmentally friendly way.

[0021] REFERENCES

[0022] [1] Callister D., Rethwisch D.G. 2007, Material Science and Engineering Calliester 577-619, Wiley Amerika.

[0023] [2] Yang Y., Zhang H., Yan Y. 2019, Synthesis of CNTs on stainless steel microfibrous composite by CVD: Effect of synthesis condition on carbon nanotube growth and structure. Composites Part B: Engineering, 160, p.369-383.

[0024] [3] Yang, G., Cheng, F„ Zuo, S„ Zhang, J., Xu, Y„ Hu, Y„ Hu, X. 2023, Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites. Polymers, 15, 2309.

Claims

CLAIMS1. Production method of a carbon nanotube (CNT) / metal nanocomposite powder for use in additive manufacturing and thermal spraying processes, comprising the process steps of: i. mixing carbon nanotubes (CNT) and metallic powders in polyvinyl alcohol (PVA) and pure water, ii. mixing metal powders and CNTs in an ultrasonic mixer to ensure a homogeneous mixture, and iii. producing nano-sized composite powder from carbon nanotube and metal powder by spray drying method.

2. A carbon nanotube (CNT) / metal nanocomposite powder produced by a method according to claim 1 .