Self-lubricating and high wear-resistant aluminum alloy turning tool blade material and preparation method thereof

Abstract

The application discloses a self-lubricating and high-wear-resistance aluminum alloy turning tool piece material, which is composed of the following components in percentage by mass: C: 2.3-2.8%, Si: 2.4-2.7%, Ni: 6.0-7.0%, W: 2-3%, Cr: 0.5-1.5%, Mo: 0.5-1.5%, V: 0.5-1.0%, Al: 0.1-0.5%, and the balance of Fe. The application further discloses a preparation method of the self-lubricating and high-wear-resistance aluminum alloy turning tool piece material, and solves the problems of rough machining surface, short service life and high cutting cost caused by aluminum adhesion during the use of the aluminum alloy special turning tool piece in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of material preparation technology for lathe cutting tools, specifically relating to self-lubricating and highly wear-resistant aluminum alloy lathe cutting tool materials, and also to a method for preparing the aforementioned self-lubricating and highly wear-resistant aluminum alloy lathe cutting tool materials. Background Technology

[0002] Aluminum and aluminum alloys are widely used in many fields such as transportation, aerospace, and building decoration. To date, they remain the preferred material for achieving lightweight performance in parts and components.

[0003] With the increasing application of aluminum alloys as a key consumable in lightweight manufacturing, the volume of aluminum alloy processing is also increasing. In the aluminum alloy manufacturing sector, the consumption of machining tools has become one of the bottlenecks to expanding the profit margins of the aluminum industry chain. While high-speed steel tools with a hardness greater than 60 HRC are "good at cutting" steel harder than aluminum, they are "difficult to cut" aluminum, which is softer than steel. Therefore, to improve the quality and efficiency of aluminum processing, companies are forced to choose tungsten-cobalt cemented carbides, which are 10 times more expensive than high-speed steel. However, the problem of aluminum cutting is not solved by the insufficient hardness of high-speed steel. Cemented carbides have extremely high hardness but poor toughness and brittleness. The cutting edge is prone to chipping and damage during manufacturing and transportation, increasing the cost of aluminum alloy cutting.

[0004] Aluminum alloys, due to their low hardness (around 120 HB at most) and high plasticity, are prone to deformation during cutting, leading to significant friction between the chips and the cutting tool face. The heat generated by friction and deformation softens the aluminum alloy chips, making them difficult to break. This prevents timely heat dissipation, triggering an "aluminothermic reaction" and causing adhesion. Adhesion increases frictional resistance, further exacerbating friction, creating a vicious cycle that prevents cutting or drastically deteriorates the cutting surface. Therefore, the fundamental material principle behind the challenges in cutting aluminum alloys is not insufficient tool hardness, but rather the "aluminothermic reaction" between aluminum and iron on the primary and secondary cutting surfaces, resulting in adhesion and preventing the cutting process. To address this, it is necessary to solve the Al / Fe adhesion problem during aluminum alloy cutting while simultaneously considering tool manufacturing costs, improving the cost-effectiveness of aluminum alloy cutting, and promoting the further development of the domestic aluminum processing industry. Summary of the Invention

[0005] One objective of this invention is to provide a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which solves the problems of low workpiece surface quality, short tool life, and high cost of aluminum alloy cutting caused by aluminum adhesion to the cutting tool.

[0006] Another objective of this invention is to provide a method for preparing self-lubricating and highly wear-resistant aluminum alloy cutting tool materials.

[0007] One technical solution adopted in this invention is a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which is composed of the following raw material components by mass percentage: C: 2.3%~2.8%, Si: 2.4%~2.7%, Ni: 6.0%~7.0%, W: 2%~3%, Cr: 0.5%~1.5%, Mo: 0.5%~1.5%, V: 0.5%~1.0%, Al: 0.1%~0.5%, with the balance being Fe.

[0008] Another technical solution adopted in this invention is,

[0009] A method for preparing self-lubricating and highly wear-resistant aluminum alloy cutting tool material, characterized by the following specific steps:

[0010] Step 1: Weigh the raw materials;

[0011] Step 2: Place the raw materials, inoculant, and spheroidizing agent into an induction furnace for high-temperature melting, then inject them into an intermediate frequency furnace, and perform horizontal drawing through a water-cooled crystallizer. After solidification, the profile is obtained.

[0012] Step 3: Perform stress-relief annealing on the profile to obtain a self-lubricating and highly wear-resistant aluminum alloy cutting tool material.

[0013] The invention is further characterized in that,

[0014] The raw materials in step 1 are mixed in the following mass percentages: 81.75–84.25% bread iron, 6.15–7.25% nickel plate, 3.5–4.25% ferrotungsten, 3.5–4.5% ferrochrome, 1.75–2.5% ferromolybdenum, 1.25–1.75% ferrovanadium, and 0.5–1.5% aluminum.

[0015] In step 2, the mixture is melted at a high temperature of 1460℃~1500℃ in an induction furnace to obtain a mixed liquid.

[0016] In step 2, the temperature of the molten iron in the ladle is 1460℃~1500℃, and it is held at that temperature for 10 minutes.

[0017] Step 2: Inject into the medium-frequency furnace, through a diameter of... Alternatively, a water-cooled crystallizer with a thickness of 40mm is used to perform horizontal drawing at a speed of 0.8m per minute, resulting in a profile with a diameter of 40mm or a thickness of 40mm after solidification.

[0018] In step 2, the density of graphite spheres at the center of the profile should not be less than 500 spheres / mm². 2 With a spheroidization rate ≥90%, the resulting as-cast microstructure of the profile is: martensite + alloy carbides + spherical graphite.

[0019] The stress-relief annealing process in step 3 is as follows: the continuously cast profile obtained in step 2 is placed in a muffle furnace and heated to 200°C at a rate of ≤6°C per minute. After holding at the temperature for 2 to 3 hours, the furnace is cooled to room temperature to obtain a martensite + alloy carbide + spherical graphite structure without residual stress, with a hardness higher than 60HRC.

[0020] The self-lubricating and highly wear-resistant aluminum alloy cutting tool obtained in step 3 is composed of the following mass percentages: C: 2.3%–2.8%, Si: 2.4%–2.7%, Ni: 6.0%–7.0%, W: 2%–3%, Cr: 0.5%–1.5%, Mo: 0.5%–1.5%, V: 0.5%–1.0%, Al: 0.1%–0.5%, with the balance being Fe.

[0021] The beneficial effects of this invention are as follows: Through horizontal continuous casting technology and subsequent heat treatment, including stress-relief annealing, the hardness exceeds 60 HRC, meeting the high hardness and red hardness requirements of turning tool inserts. Compared to high-speed steel and cemented carbide, it has extremely low production costs while maintaining high wear resistance. Furthermore, the internal structure is inlaid with a large number of fine and uniformly distributed spherical graphite particles. During cutting, the graphite spreads across the tool surface, forming a graphite isolation layer between the tool and the aluminum workpiece, achieving anti-aluminum adhesion and low friction characteristics. This avoids aluminum adhesion to the tool surface, which affects cutting quality and processing efficiency, significantly improving the service life of turning inserts and realizing the research and development and preparation of turning tool materials for aluminum products. Attached Figure Description

[0022] Figure 1 This is a microstructure diagram of the distribution of spherical graphite in the stress-relief annealed profile prepared in Example 1 of the present invention;

[0023] Figure 2 This is a microhardness diagram of the matrix structure after stress-relief annealing in Embodiment 1 of the present invention;

[0024] Figure 3 This is a scanning electron microscope image of the tissue after stress-relief annealing in Embodiment 1 of the present invention;

[0025] Figure 4 This is the energy dispersive spectroscopy (EDS) spectrum after stress-relief annealing in Embodiment 1 of the present invention;

[0026] Figure 5 This is a photograph of the cutting tool prepared in Example 1 of the present invention after cutting aluminum. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] The self-lubricating and highly wear-resistant aluminum alloy cutting tool material of this invention is composed of the following raw material components by mass percentage: C: 2.3%~2.8%, Si: 2.4%~2.7%, Ni: 6.0%~7.0%, W: 2%~3%, Cr: 0.5%~1.5%, Mo: 0.5%~1.5%, V: 0.5%~1.0%, Al: 0.1%~0.5%, with the balance being Fe.

[0029] The present invention relates to a method for preparing a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which is specifically implemented according to the following steps:

[0030] Step 1: Weigh the raw materials;

[0031] The raw materials are mixed in the following mass percentages: 81.75-84.25% bread iron, 6.15-7.25% nickel plate, 3.5-4.25% ferrotungsten, 3.5-4.5% ferrochrome, 1.75-2.5% ferromolybdenum, 1.25-1.75% ferrovanadium, and 0.5-1.5% aluminum;

[0032] Step 2: Place the raw materials, inoculant, and spheroidizing agent into an induction furnace for high-temperature melting, then inject them into an intermediate frequency furnace, and perform horizontal drawing through a water-cooled crystallizer. After solidification, the profile is obtained.

[0033] The molten iron is melted at a high temperature of 1460℃~1500℃ in an induction furnace to obtain a mixed liquid; the temperature of the molten iron in the ladle is 1460℃~1500℃, and it is held at that temperature for 10 minutes; then it is poured into a medium-frequency furnace, passing through a diameter of [missing information]. Alternatively, a water-cooled crystallizer with a thickness of 40mm is used for horizontal drawing at a speed of 0.8m per minute. After solidification, a profile with a diameter of 40mm or a thickness of 40mm is obtained, and the density of graphite spheres at the center of the profile is not less than 500 spheres / mm². 2 With a spheroidization rate ≥90%, the resulting as-cast microstructure of the profile is: martensite + alloy carbides + spherical graphite.

[0034] Step 3: Perform stress-relief annealing on the profile to obtain a self-lubricating and highly wear-resistant aluminum alloy cutting tool material.

[0035] The stress-relief annealing process is as follows: the continuously cast profile obtained in step 2 is placed in a muffle furnace and heated to 200°C at a rate of ≤6°C per minute. After holding at the temperature for 2 to 3 hours, the furnace is cooled to room temperature to obtain a martensite + alloy carbide + spherical graphite structure without residual stress, with a hardness higher than 60HRC.

[0036] The self-lubricating and highly wear-resistant aluminum alloy cutting tool obtained in step 3 is composed of the following mass percentages: C: 2.3%–2.8%, Si: 2.4%–2.7%, Ni: 6.0%–7.0%, W: 2%–3%, Cr: 0.5%–1.5%, Mo: 0.5%–1.5%, V: 0.5%–1.0%, Al: 0.1%–0.5%, with the balance being Fe.

[0037] This invention relates to a method for preparing self-lubricating and highly wear-resistant aluminum alloy lathe cutting tool materials. Graphite, with its hexagonal lamellar structure, possesses advantages such as high thermal conductivity and low friction. Graphite spheres are uniformly embedded in a high-speed steel-like matrix (iron-ductile graphite metal). Under the action of tangential force at the cutting interface, the graphite spreads and forms a film along the surface. This reduces the "source" of frictional heat generation at the interface—the coefficient of friction—and inhibits the aluminothermic reaction between aluminum and iron, preventing adhesion formation. However, while reducing Al / Fe adhesion at the cutting surface, the "red hardness" index of the cutting tool must also be considered. This invention prepares an alloy-hardening iron-ductile graphite metal through alloying principles and red hardness control processes, solving the adhesion problem during the cutting of aluminum alloy lathe cutting tools, improving cutting efficiency, and significantly reducing the cost of aluminum alloy cutting. This achieves dual control and optimization of aluminum alloy cutting quality and cost.

[0038] Graphite also possesses excellent thermal conductivity and sound absorption / vibration reduction properties, lowering noise pollution during the cutting process. Compared to high-speed steel and cemented carbide, it boasts extremely low production costs and superior high-temperature red hardness. Furthermore, it contains strong carbide-forming elements such as Cr, Mo, W, and V. During cutting, as the temperature rises, these elements form high-hardness carbides that disperse and precipitate, preventing the tool from softening due to frictional heat and reducing its hardness. This ensures the required red hardness and wear resistance of aluminum alloy cutting inserts during operation. Therefore, the development of this dedicated aluminum alloy cutting insert material will have a profound impact on aluminum alloy production and its machining processes.

[0039] Example 1

[0040] The present invention relates to a method for preparing a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which is specifically implemented according to the following steps:

[0041] Step 1: Weigh and mix the raw materials: 308kg bread iron, 38kg nickel plate, 15kg ferrotungsten, 14kg ferrochrome, 7kg ferromolybdenum, 5kg ferrovanadium, and 2kg aluminum according to the required composition.

[0042] Step 2: Combine the raw materials weighed in Step 1 with 40 kg of inoculant / spheroidizing agent and melt them together in an induction furnace at 1460℃~1500℃ to obtain a mixed liquid. Pour the high-temperature mixed liquid into a medium-frequency furnace, through a diameter of [missing information]. A water-cooled crystallizer is used for horizontal drawing at a speed of 0.8 meters per minute. After solidification, a profile with a diameter of 40 mm is obtained, and the density of graphite spheres at the center of the profile is not less than 500 spheres / mm². 2 The sphericity is ≥90%. The microstructure of the profile prepared after step 2 in Example 1 is shown in the image. Figure 1 As shown, the spherical graphite in the profile is evenly distributed and fine, with a graphite spheroid density greater than 500 spheroids / mm². 2 .

[0043] Step 3: Place the continuously cast profile into a muffle furnace and heat it to 200°C at a rate of ≤6°C per minute. Maintain this temperature for 2–3 hours, then furnace cool to room temperature. After stress-relief annealing, the microstructure consists of martensite + alloy carbides + graphite, with a hardness higher than 60 HRC. The microstructure and Vickers hardness distribution obtained after step 3 in Example 1 are shown below. Figure 2 , Figure 3 , Figure 4 As shown, the microstructure consists of martensite + alloy carbides + spheroidal graphite, and the Vickers hardness of the martensitic microstructure is approximately 550 HV. 0.025 The alloy carbide hardness is 1020 HV. 0.025 The cutting blade sample prepared after step 3 in Example 1, such as Figure 5 As shown.

[0044] Example 2

[0045] The present invention relates to a method for preparing a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which is specifically implemented according to the following steps:

[0046] Step 1: Weigh and mix the raw materials: 315kg bread iron, 43kg nickel plate, 19kg ferrotungsten, 17kg ferrochrome, 9kg ferromolybdenum, 8kg ferrovanadium, and 4kg aluminum according to the required composition.

[0047] Step 2: The raw materials weighed in Step 1, together with 42 kg of inoculant and spheroidizing agent, are melted at a high temperature of 1460℃~1500℃ in an induction furnace to obtain a mixed liquid. The high-temperature mixed liquid is then injected into a medium-frequency furnace, through a diameter of [missing information]. A water-cooled crystallizer is used for horizontal drawing at a speed of 0.8 meters per minute. After solidification, a profile with a diameter of 40 mm is obtained, and the density of graphite spheres at the center of the profile is not less than 500 spheres / mm². 2 The sphericity rate is ≥90%.

[0048] Step 3: Place the continuously cast profile into a muffle furnace and heat it to 200°C at a rate of ≤6°C per minute. After holding the temperature for 2-3 hours, cool it to room temperature. The microstructure after stress-relief annealing is martensite + alloy carbides + graphite, and the microstructure hardness is higher than 60HRC.

[0049] Example 3

[0050] The present invention relates to a method for preparing a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which is specifically implemented according to the following steps:

[0051] Step 1: Weigh and mix the raw materials according to the required composition: 320kg bread iron, 45kg nickel plate, 17kg ferrotungsten, 16kg ferrochrome, 8kg ferromolybdenum, 6kg ferrovanadium, and 3kg aluminum.

[0052] Step 2: The raw materials weighed in Step 1, together with 41 kg of inoculant and spheroidizing agent, are melted at a high temperature of 1460℃~1500℃ in an induction furnace to obtain a mixed liquid. The high-temperature mixed liquid is then injected into a medium-frequency furnace, through a diameter of [missing information]. A water-cooled crystallizer is used for horizontal drawing at a speed of 0.8 meters per minute. After solidification, a profile with a diameter of 40 mm is obtained, and the density of graphite spheres at the center of the profile is not less than 500 spheres / mm². 2 The sphericity rate is ≥90%.

[0053] Step 3: Place the continuously cast profile into a muffle furnace and heat it to 200°C at a rate of ≤6°C per minute. After holding the temperature for 2-3 hours, furnace cool to room temperature. The microstructure after stress-relief annealing is martensite + alloy carbides + graphite, with a hardness higher than 60 HRC.

[0054] Example 4

[0055] The present invention relates to a method for preparing a self-lubricating and highly wear-resistant aluminum alloy cutting tool material, which is specifically implemented according to the following steps:

[0056] Step 1: Weigh and mix the raw materials according to the required composition: 318kg bread iron, 48kg nickel plate, 18kg ferrotungsten, 15kg ferrochrome, 7kg ferromolybdenum, 5kg ferrovanadium, and 2kg aluminum.

[0057] Step 2: The raw materials weighed in Step 1, together with 41 kg of inoculant and spheroidizing agent, are melted at a high temperature of 1460℃~1500℃ in an induction furnace to obtain a mixed liquid. The high-temperature mixed liquid is then injected into a medium-frequency furnace, through a diameter of [missing information]. A water-cooled crystallizer is used for horizontal drawing at a speed of 0.8 meters per minute. After solidification, a profile with a diameter of 40 mm is obtained, and the density of graphite spheres at the center of the profile is not less than 500 spheres / mm². 2 The sphericity rate is ≥90%.

[0058] Step 3: Place the continuously cast profile into a muffle furnace and heat it to 200°C at a rate of ≤6°C per minute. After holding the temperature for 2-3 hours, furnace cool to room temperature. The microstructure after stress-relief annealing is martensite + alloy carbides + graphite, with a hardness higher than 60 HRC.

[0059] This invention relates to a method for preparing self-lubricating and highly wear-resistant aluminum alloy cutting tool materials. The spheroidal graphite significantly reduces the cutting effect on the matrix and prevents aluminum from sticking, thus avoiding tool sticking during cutting and affecting cutting efficiency and surface quality. It also possesses good thermal conductivity and sound absorption / vibration damping properties. During use, as the tool temperature rises during cutting, high-hardness alloy carbides such as Cr / Mo / V / W are dispersed and precipitated, exhibiting red hardness and high wear resistance, preventing the tool from softening and reducing hardness due to tempering during cutting.

[0060] Compared with high-speed steel and cemented carbide in cutting aluminum alloys, cutting inserts made of this material, when used for cutting aluminum alloy profiles, show no significant reduction in hardness after cutting due to their excellent self-lubricating properties and high wear resistance. Cutting efficiency is increased by 80%, the aluminum alloy cutting surface is smooth, the amount of aluminum adhering to the tool surface is reduced by 50%, and the service life is increased by nearly 2 times.

[0061] The aluminum alloy cutting tool prepared using this invention has a large number of fine and uniformly distributed spherical graphite embedded in its internal structure. During the cutting process, the graphite spreads across the tool surface, forming a graphite isolation layer between the tool and the aluminum workpiece. This achieves anti-aluminum adhesion and self-lubricating properties, avoiding the impact of aluminum adhesion on the tool surface on cutting quality and processing efficiency. It significantly improves the service life of the cutting tool and the surface quality of the cut aluminum alloy, ensuring cutting accuracy and suppressing tool adhesion.

Claims

1. A self-lubricating and high wear resistant aluminium alloy turning tool insert material, characterized in that, It is composed of the following raw material components by mass percentage: C: 2.3%~2.8%, Si: 2.4%~2.7%, Ni: 6.0%~7.0%, W: 2%~3%, Cr: 0.5%~1.5%, Mo: 0.5%~1.5%, V: 0.5%~1.0%, Al: 0.1%~0.5%, with the balance being Fe.

2. The method for preparing self-lubricating and high wear-resistant aluminum alloy turning tool piece material, characterized in that, The specific steps are as follows: Step 1: Weigh the raw materials; Step 2: Place the raw materials, inoculant, and spheroidizing agent into an induction furnace for high-temperature melting, then inject them into an intermediate frequency furnace, and perform horizontal drawing through a water-cooled crystallizer. After solidification, the profile is obtained. Step 3: Perform stress-relieving annealing on the profile to obtain a self-lubricating and highly wear-resistant aluminum alloy cutting tool material. In step 2, the mixture is melted at a high temperature of 1460℃~1500℃ in an induction furnace to obtain a mixed liquid; In step 2, the temperature of the molten iron in the ladle is 1460℃~1500℃, and the temperature is maintained for 10 minutes. In step 2, the material is injected into an intermediate frequency furnace and then horizontally drawn through a water-cooled crystallizer with a diameter of φ40mm or a thickness of 40mm at a speed of 0.8m per minute. After solidification, a profile with a diameter of 40mm or a thickness of 40mm is obtained. The graphite ball density at the center of the profile in step 2 is not less than 500 / mm 2 The spheroidization rate is greater than or equal to 90%, and the as-cast structure of the profile is martensite + alloy carbide + spherical graphite. The stress-relief annealing process in step 3 is as follows: the continuous casting profile obtained in step 2 is placed in a muffle furnace and heated to 200°C at a rate of ≤6°C per minute. After holding at the temperature for 2-3 hours, the furnace is cooled to room temperature to obtain a martensite + alloy carbide + spherical graphite structure without residual stress, with a hardness higher than 60 HRC. The self-lubricating and highly wear-resistant aluminum alloy cutting tool obtained in step 3 is composed of the following mass percentages: C: 2.3%~2.8%, Si: 2.4%~2.7%, Ni: 6.0%~7.0%, W: 2%~3%, Cr: 0.5%~1.5%, Mo: 0.5%~1.5%, V: 0.5%~1.0%, Al: 0.1%~0.5%, with the balance being Fe.

Images