Laminate composite shield alloy construction method and alloy blade

Abstract

This invention relates to the field of cemented carbide insert manufacturing technology, specifically disclosing a method for constructing a laminated composite cemented carbide insert. The method includes: preparing a high-performance cemented carbide material A and a low-grade cemented carbide material B, wherein A is used for the cutting part and B is used for the non-cutting part; according to the insert structure design, the weight ratio of A to B and the powder loading height ratio are sequentially filled into the same mold to form a layered powder blank; after molding and high-temperature, high-pressure sintering, A and B are densely bonded to obtain a laminated composite insert. This insert can be an indexable positive insert, an indexable negative insert, a parting and grooving tool, etc., with a metallurgical bond at the lamination interface and a smooth, protrusion-free surface. This invention, through precise control of material distribution and process parameters, significantly reduces the cost of cemented carbide materials while ensuring excellent cutting performance. The process is simple and suitable for mass production.

Description

Technical Field

[0001] This invention relates to the field of cemented carbide cutting tool manufacturing technology, and more specifically, to a method for constructing a multilayered composite carbide cutting tool. Background Technology

[0002] Carbide inserts, as high-performance cutting tools, possess high hardness, high strength and toughness, high wear resistance, and good thermal stability. They are widely used in manufacturing industries, particularly in the automotive, aerospace, petrochemical, medical device, and electronics manufacturing sectors. These industries continue to grow their demand for high-performance inserts, thus requiring high-precision and high-efficiency machining processes to meet quality and production requirements.

[0003] However, with the growth in demand, the main components of cemented carbide inserts, such as tungsten carbide, cobalt, and nickel, are expensive, and their manufacturing process is complex, leading to a gradual increase in the cost of cemented carbide inserts. Developing a laminated composite alloy structure technology, using more cost-effective raw materials—for example, using high-performance cemented carbide material A for the cutting portion of the same insert, and using a slightly lower grade cemented carbide material B for the non-cutting portion—avoids the excessive use of high-performance cemented carbide materials, which would result in cost waste. How to reduce production costs and improve product performance through the development of laminated composite alloy structure technology is a common challenge in the industry.

[0004] Currently, there are four main types of composite alloy construction technology: (1) Carburizing method: Carbon atoms are diffused into the interior of the alloy at high temperature to form carbon concentration stratification. This method can precisely control the carbon distribution, but the process is complex and difficult to industrialize; (2) Powder metallurgy method: This method involves mixing metal powders of different compositions in proportion, then pressing them into the required shape, and sintering them at high temperature to form a metallurgical bond between the powders, resulting in an alloy with a layered structure. (3) Chemical vapor deposition method: This method involves placing the substrate in a reaction chamber, controlling the reaction conditions, and causing a chemical reaction on the substrate surface. Once the reaction is complete, a layered alloy structure is deposited, which is suitable for preparing layered alloy parts with specific chemical compositions and properties. (4) Laser cladding method: A laser beam is used to melt and deposit alloy powder onto the substrate surface. By controlling the laser parameters and powder delivery speed, different layers of alloy structure can be obtained, but this method is costly, complex, and difficult to mass-produce.

[0005] Therefore, it is necessary to develop a layered composite rainbow shield alloy construction technology to improve product lifespan and reduce mass production costs. Summary of the Invention

[0006] In view of the above-mentioned technical problems in related technologies, the present invention provides a method for constructing a multilayered composite rainbow shield alloy, which can solve the above problems.

[0007] To achieve the above-mentioned technical objectives, the technical solution of the present invention is implemented as follows: The method for constructing a laminated composite rainbow shield alloy includes the following steps: Step 1: Prepare high-performance cemented carbide material A and low-grade cemented carbide material B; material A is used for the cutting part of the insert, and material B is used for the non-cutting part of the insert. The cobalt content of material A is 1 to 3 percentage points higher than that of material B, or material A contains 0.1% to 0.5% by mass of the rare metal ruthenium while material B does not contain ruthenium. Step 2: Based on the structure of the target blade, calculate the total weight and total powder loading height of the blade, and design the weight ratio and powder loading height ratio of material A to material B; Step 3: Following the design sequence, first fill material B or material A into the mold to a predetermined height, then fill another material into the same mold to another predetermined height to form a layered powder blank; first fill material B or material A into the mold to a predetermined height, then fill another material into the same mold to another predetermined height to form a layered powder blank; Step 4: Press the layered powder preform into a compact with a predetermined shape and size by compression molding; Step 5: Through high temperature and high pressure sintering, material A and material B are densely bonded together, and after cooling, a laminated composite rainbow shield alloy blade is obtained.

[0008] Furthermore, in step three: the powder loading height of material B or material A is determined by the formula, where H is the powder loading height, ρ is the compact height, and q is the loose powder density; the unit weight of material B or material A is determined by the formula, where H is the compact unit weight, q is the alloy volume, ρ is the powder density, and q is the powder burn-off rate.

[0009] Furthermore, the unit weight ratio mentioned in step two is A:B=1:6~8, and the powder loading height ratio is A:B=1:2~4; and, at the layering point, there is no raised boundary on the blade surface.

[0010] Furthermore, the laminated composite rainbow shield alloy blade has a two-layer or three-layer structure; when it is a three-layer structure, its material distribution is A / B / A, and the powder loading height ratio is A:B:A=1:2:1.

[0011] Furthermore, the total number of layers in the stack ranges from 2 to 6.

[0012] A layered composite rainbow shield alloy insert, wherein the insert is an indexable circular milling cutter, a parting grooving cutter, or an indexable negative milling cutter.

[0013] Furthermore, the cutting portion of the blade is made of high-performance cemented carbide material A, and the non-cutting portion is made of low-grade cemented carbide material B, and the interface between the high-performance cemented carbide material A and the low-grade cemented carbide material B is a metallurgical bonding interface.

[0014] The beneficial effects of this invention are: This invention achieves optimized material functional zoning and usage by using high-performance cemented carbide material A exclusively for the cutting portion of the insert, while using lower-cost, lower-grade cemented carbide material B for the non-cutting portion, and by precisely designing the weight ratio and powder loading height ratio of the two materials. Compared to inserts made entirely of high-performance materials, this reduces material costs by approximately 60% or more. Simultaneously, because the cutting edge retains the high toughness, high thermal shock resistance, and high wear resistance of material A, the overall insert life can be increased by more than three times compared to inserts made entirely of material B.

[0015] This invention precisely calculates the powder loading height and unit weight of each powder layer using formulas, and optimizes the unit weight ratio and powder loading height ratio to ensure consistent shrinkage rates of different materials during pressing and sintering. This results in no protruding boundaries at the layer interface, a smooth blade surface, and no impact on clamping and positioning accuracy. Simultaneously, after high-temperature and high-pressure sintering, materials A and B form a strong metallurgical bond interface, free from delamination, cracks, or other appearance defects. This method supports various stacked structures, including two, three, and up to six layers, and can flexibly adapt to various blade types such as indexable positive blades, indexable negative blades, and cutting / grooving blades. The process is simple, easy to mass-produce, and has a high yield. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] The present invention will now be described in further detail with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of a laminated composite rainbow shield two-layer alloy blade; Figure 2 This is a schematic diagram of a laminated composite rainbow shield three-layer structure alloy blade. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0020] As shown in the figure, this invention discloses a laminated composite carbide cutting tool and its preparation method. The core of this method lies in precisely controlling the loading sequence, unit weight ratio, and powder height ratio of different grades of cemented carbide powders. Through molding and high-temperature, high-pressure sintering, a composite cutting tool with clearly defined functional zones and a metallurgically bonded interface is formed by combining high-performance and low-grade materials. This method is simple, easy to mass-produce, and significantly reduces material costs while ensuring cutting performance.

[0021] 1. Detailed description of materials A and B The core difference between the high-performance cemented carbide material A and the low-grade cemented carbide material B in this invention lies in their composition design. Specific implementation methods include, but are not limited to, the following two: Option 1 (Cobalt Content Difference): Material A has a cobalt (Co) content 1-3 percentage points higher than Material B. For example, if Material A has a Co content of 8%-12%, then Material B's Co content would be 5%-11%. Cobalt, as a binder phase, effectively improves the alloy's toughness, bending strength, and thermal shock resistance, making it ideal for the cutting edge portion that bears the main cutting forces. Meanwhile, Material B's lower cobalt content ensures higher hardness and wear resistance in the non-cutting parts, and it is also more cost-effective.

[0022] Option 2 (Addition of rare metal ruthenium): Material A contains 0.1%~0.5% by mass of the rare metal ruthenium (Ru), while Material B contains no ruthenium. The addition of ruthenium significantly refines the grain size, improves solid solution strengthening, and enhances the alloy's corrosion resistance and high-temperature oxidation resistance. This results in Material A achieving machinability far exceeding that of conventional high-performance alloys, making it particularly suitable for machining difficult-to-machine materials (such as titanium alloys and nickel-based superalloys). Material B, on the other hand, does not require the addition of expensive ruthenium, thus controlling costs.

[0023] In actual production, one or a combination of the above options can be flexibly selected based on the specific material to be processed by the target blade (such as steel, cast iron, high-temperature alloy) and the cost budget.

[0024] 2. Regarding the parameter design in steps two and three To ensure a smooth transition by preventing visible or usable protrusions at the delamination points of the blade after sintering, this invention provides precise calculation and design methods.

[0025] Powder loading height calculation: The powder loading height of a single layer is determined by a formula. Where H is the designed height of the corresponding layer in the final compact, ρ is the density of the final compact (which can be considered as the theoretical density of the alloy), and ρ is the loose packing density of the corresponding powder. This formula takes into account the compression ratio of the powder during the pressing process and is the theoretical basis for ensuring precise matching of the heights of each compact layer.

[0026] The unit weight of the pressed compact is calculated using the following formula: where is the volume of that layer in the final alloy product, ρ is the powder density, and q is the powder burn-off rate (typically 0.5%~2%, depending on the forming agent and sintering process). This formula ensures that the quality of each layer in the final sintered body matches the design objectives.

[0027] Based on the above formulas and extensive experimental results, a particularly preferred parameter range is: a unit weight ratio of material A to material B of 1:7 and a powder loading height ratio of 1:3. Within this range, the two powders can achieve the most complete particle migration and interlocking during pressing, and the shrinkage rate after sintering is consistent. This results in a smooth surface at the lamination interface of the blade, without any protrusions or depressions, which does not affect the clamping and positioning accuracy and performance of the blade.

[0028] 3. Regarding the stacked structure and number of layers The laminated composite structure of the present invention is not limited to a simple two-layer structure, and can be flexibly designed according to the geometry of the blade and the stress conditions.

[0029] Two-layer structure (A / B): Suitable for indexable positive inserts, parting and grooving tools, etc. High-performance material A constitutes the entire cutting edge, while low-grade material B constitutes the tool body base. Simple structure, highest cost-effectiveness.

[0030] Three-layer structure (A / B / A): Suitable for indexable negative-profile inserts. Its material distribution is A / B / A, and the powder loading height ratio is A:B:A = 1:2:1. This symmetrical design ensures that both sides of the insert have high-performance cutting edges. When one side wears out, the other side can be indexed for use, greatly improving the insert's lifespan and utilization rate. After sintering, the two layers of A material naturally connect at the edges, enclosing the B material in the middle, forming a "sandwich" structure.

[0031] Multi-layer structure (2 to 6 layers): The total number of layers in this invention can be 2, 3, 4, 5, or 6. For example, for certain inserts with complex chip breaker grooves or special cutting edge shapes, a multi-layer alternating structure such as A / B / A / B or A / B / A / B / A can be designed to precisely control the material properties of each tiny area and achieve gradient functionality. This can be achieved by sequentially filling powder; even with a maximum of 6 layers, process stability and yield can still be guaranteed. Specific Implementation

[0032] Example 1: Indexable circular milling cutter (two-layer structure), such as Figure 1 As shown This embodiment is used to manufacture an indexable circular milling cutter with a diameter of 12mm.

[0033] Material preparation: Prepare high-performance cemented carbide material A (containing 12% Co) and low-grade cemented carbide material B (containing 9% Co). Both powders contain appropriate amounts of forming agents (such as paraffin or PEG).

[0034] Parameter Design: Based on the final dimensions of the cutting tool, the alloy height is calculated to be 4.85 mm, and the blank height is 6 mm. The blank height of layer A (cutting edge) is designed to be 1.5 mm, and layer B (base layer) to be 4.5 mm. The final design unit weight ratio is A:B = 1:7, and the powder loading height ratio is A:B = 1:3.1. The actual powder loading heights of powders A and B are calculated using the formulas. For example, if the blank density ρ = 11.5 g / cm³, and the loose packing density of powder A A = 3.5 g / cm³, then the powder loading height of A A is A = 1.5 × (11.5 / 3.5) ≈ 4.93 mm.

[0035] Filling and pressing: The automatic press's hopper system first fills the mold with calculated B powder to a predetermined height, then fills it with A powder. Unidirectional or bidirectional pressing is used, with a pressing pressure of 150-200 MPa and a holding time of 1-2 seconds, forming a compact.

[0036] Sintering: The compact is placed in a vacuum sintering furnace or pressure sintering furnace and sintered at 1380℃-1450℃ under argon protection or low pressure (such as 5MPa) for 1-2 hours to achieve a dense metallurgical bond between layers A and B.

[0037] Results: The obtained indexable circular end mill exhibits good toughness and impact resistance at the cutting edge, as well as high matrix hardness. When machining alloys, its lifespan is increased by more than 3 times compared to all-B material inserts; and material costs are reduced by approximately 60% compared to all-A material inserts.

[0038] Example 2: Cutting and grooving blade (two-layer structure) This embodiment is used to manufacture a cutting and grooving blade with a width of 3mm.

[0039] Material preparation: Prepare high-performance cemented carbide material A (containing 0.3wt% Ru and 10% Co) and low-grade cemented carbide material B (containing no Ru and 10% Co).

[0040] Parameter design: Based on the blade shape, the total blank height is calculated to be 10mm. The height of layer A (cutting edge) is designed to be 2mm, and the height of layer B (blade holder clamping part) is designed to be 8mm. The unit weight ratio is designed as A:B=1:6.5, and the powder loading height ratio is designed as A:B=1:2.8.

[0041] Filling, pressing and sintering: The steps are the same as in Example 1. Special attention should be paid to controlling the accuracy of the powder loading height of layers A and B to ensure that the delamination is located at a reasonable position behind the cutting edge after sintering and that the surface is flat.

[0042] Results: The obtained cutting and grooving tool exhibits excellent resistance to crater wear and oxidation in layer A due to the presence of ruthenium. When machining titanium alloy Ti-6Al-4V, it shows a cutting life increase of over 50% compared to similar inserts without ruthenium, while increasing tool cost by only about 10%.

[0043] Example 3: Indexable negative end mill (three-layer structure), such as Figure 2 As shown; This embodiment is used to manufacture a square indexable negative milling insert.

[0044] Materials preparation: Same as in Example 1 (or Example 2).

[0045] Parameter design: The blade is for double-sided use and designed with a symmetrical three-layer structure A / B / A. The total compact height is 8mm, and the compact heights of each layer are designed as A1=2mm, B=4mm, and A2=2mm. The powder loading height ratio is A:B:A=1:2:1. Calculate the actual powder loading height of each layer.

[0046] Filling, pressing, and sintering: The filling sequence is as follows: first fill the lower layer A (A2), then the middle layer B, and finally the upper layer A (A1). After each layer is filled, the powder surface can be kept smooth by slight vibration or scraping. The pressing and sintering processes are the same as in Example 1.

[0047] Results: The obtained indexable negative end mill has two main cutting surfaces made of high-performance material A. When machining high-hardness materials (such as hardened steel HRC55), it offers long insert life and excellent overall economic efficiency due to its indexable design on both sides. After sintering, the interface bonding is strong, with no delamination, cracks, or other defects.

[0048] Comparative Example Comparative Example 1: The same geometry as Example 1 was used, but the entire sample was made using high-performance material A.

[0049] Result: The cutting performance of the insert is excellent, but the material cost is high and the economic efficiency is poor.

[0050] Comparative Example 2: The same geometric dimensions and material layers as in Example 1 were used, but the powder filling height ratio was not calculated according to the formula of this invention, but was arbitrarily set to 1:1.

[0051] Result: After sintering, due to the mismatch in shrinkage rates between layers A and B, a noticeable raised "step" was generated at the layer interface, which prevented the blade from being accurately clamped and positioned on the cutter head or cutter bar, resulting in product scrap.

[0052] As can be seen from the above embodiments and comparative examples, the technical solution provided by the present invention achieves a balance between high performance and low cost, and between complex structure and simplified process by precisely controlling the material composition, powder loading parameters and laminated structure, and has significant technological progress and industrial practical value.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a laminated composite rainbow shield alloy blade, characterized in that, Includes the following steps: Step 1: Prepare high-performance cemented carbide material A and low-grade cemented carbide material B; material A is used for the cutting part of the insert, and material B is used for the non-cutting part of the insert. The cobalt content of material A is 1 to 3 percentage points higher than that of material B, or material A contains 0.1% to 0.5% by mass of the rare metal ruthenium while material B does not contain ruthenium. Step 2: Based on the structure of the target blade, calculate the total weight and total powder loading height of the blade, and design the weight ratio and powder loading height ratio of material A to material B; Step 3: Following the design sequence, first fill material B or material A into the mold to a predetermined height, then fill another material into the same mold to another predetermined height to form a layered powder blank; first fill material B or material A into the mold to a predetermined height, then fill another material into the same mold to another predetermined height to form a layered powder blank; Step 4: Press the layered powder preform into a compact with a predetermined shape and size by compression molding; Step 5: Through high temperature and high pressure sintering, material A and material B are densely bonded together, and after cooling, a laminated composite rainbow shield alloy blade is obtained.

2. The method for preparing a laminated composite rainbow shield alloy blade according to claim 1, characterized in that, In step three: the powder loading height of material B or material A is determined by the formula, where H is the powder loading height, ρ is the compact height, and q is the loose powder density; the unit weight of material B or material A is determined by the formula, where H is the compact unit weight, ρ is the alloy volume, ρ is the powder density, and q is the powder burn-off rate.

3. The method for preparing a laminated composite rainbow shield alloy blade according to claim 1, characterized in that, The unit weight ratio mentioned in step two is A:B=1:6~8, and the powder loading height ratio is A:B=1:2~4; furthermore, at the layering point, there is no raised boundary on the blade surface.

4. The method for preparing a laminated composite rainbow shield alloy blade according to claim 1, characterized in that, The laminated composite rainbow shield alloy blade has a two-layer structure or a three-layer structure; when it is a three-layer structure, its material distribution is A / B / A, and the powder loading height ratio is A:B:A=1:2:

1.

5. The method for preparing a laminated composite rainbow shield alloy blade according to claim 1, characterized in that, The total number of layers in the stack is 2 to 6.

6. A laminated composite rainbow shield alloy blade, characterized in that, It is prepared by any one of claims 1 to 5.

7. The laminated composite rainbow shield alloy blade according to claim 6, characterized in that, The blade is an indexable positive blade, an indexable negative blade, or a cutting and grooving blade.

8. The laminated composite rainbow shield alloy blade according to claim 6, characterized in that, The cutting part of the blade is made of high-performance cemented carbide material A, and the non-cutting part is made of low-grade cemented carbide material B. The interface between the high-performance cemented carbide material A and the low-grade cemented carbide material B is a metallurgical bonding interface.

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