A method of manufacturing elevator safety gear wedge composite

Abstract

The application discloses a method for preparing elevator safety gear wedge composite material, comprising the following steps: step one, pretreating alloy steel material, silicon carbide ceramic powder and boron carbide ceramic powder respectively; step two, mixing the pretreated alloy steel material, the pretreated silicon carbide ceramic powder and the pretreated boron carbide ceramic powder in a ball mill according to the preset raw material content of each layer of the elevator safety gear wedge composite material, to obtain preformed material; and step three, forming the preformed material layer on a substrate by taking argon as a protective gas, to obtain the elevator safety gear wedge composite material. The elevator safety gear wedge composite material prepared by the method has good impact toughness, fatigue resistance and wear resistance, and meets the performance requirements of the safety gear wedge.

Description

Technical Field

[0001] This invention belongs to the field of molding technology, specifically relating to a method for preparing composite materials for elevator safety clamp wedges. Background Technology

[0002] When an elevator falls unexpectedly due to a malfunction, its speed exceeds the limit, causing the speed governor to activate. The safety brake then engages, bringing the elevator to a stop and ensuring passenger safety. Therefore, the safety brake is crucial for ensuring the safe operation of elevators. With population growth and the increasing number of high-rise buildings in developed areas, the demand for safe, reliable, and efficient elevators (high operating speed, heavy load capacity) is growing stronger. Under high-speed, high-load operating conditions, the friction between the elevator safety brake block and the guide rail is often accompanied by significant changes in temperature and pressure. This places stringent requirements on the comprehensive mechanical, thermal, and frictional wear properties of the safety brake block, as well as the stability of its various performance parameters during service. If the performance or service stability of the safety brake block fails to meet design requirements, the elevator is prone to safety hazards such as brake failure and sudden braking. Traditional friction braking materials (gray cast iron) often experience excessive wear under frictional heat, leading to a decrease in the coefficient of friction, thus failing to meet the safety requirements of modern high-performance elevators.

[0003] As a type of "electromechanical special equipment" that concerns life and property safety, elevators are increasingly used in modern life, and also exhibit diversity in types and functions. According to the elevator's operating speed, elevators can be divided into: (1) low-speed elevators: their rated operating speed is often less than 2m / s; (2) high-speed elevators: their rated operating speed is 4 to 8m / s, and even reaches 12.5m / s; (3) medium-speed elevators: their rated operating speed is between low-speed elevators and high-speed elevators; (4) ultra-high-speed elevators: their rated operating speed is higher than 12.5m / s. With the increasing number of high-rise buildings and the continuous progress in the research and development of high-performance elevators, elevator operating speeds are getting faster and faster. Currently, the highest operating speed of elevators in the world is 17m / s. However, with the recent occurrence of many elevator accidents, the safety and reliability of elevators have received great attention. Therefore, in the design and manufacturing of high-performance elevators, equipment safety has become one of the important performance indicators. As an important component to ensure elevator safety, the safety clamp may experience performance degradation due to the high-speed heating caused by the high-speed friction between the brake block and the guide rail during service. As a braking component of elevators, the friction performance and stability of the safety brake block are crucial indicators for ensuring elevator safety. During braking, elevators often exhibit intense frictional action within a short period. With the increasing prevalence of high-speed elevators (operating speeds of 4–8 m / s), the frictional forces and temperature variations experienced by the elevator safety brake per unit time are increasing. Therefore, the ever-increasing demands on elevator operating performance and the increasingly stringent service conditions require safety brake materials to possess higher high-temperature mechanical properties and wear resistance. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for preparing elevator safety clamp wedge composite material, addressing the shortcomings of the prior art. This method uses alloy steel, silicon carbide ceramic powder, and boron carbide ceramic powder as main raw materials. After pretreatment, the main raw materials are mixed, followed by baking, powder spreading, and laser selective melting layer deposition to obtain the elevator safety clamp wedge composite material. This composite material exhibits good impact toughness, fatigue resistance, and wear resistance, meeting the performance requirements of safety clamp wedges.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing composite material for elevator safety clamp wedges, characterized in that it includes:

[0006] Step 1: Pre-treat the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder respectively;

[0007] Step 2: According to the preset raw material content of each layer of the elevator safety clamp wedge block composite material, the pretreated alloy steel material, the pretreated silicon carbide ceramic powder and the pretreated boron carbide ceramic powder are mixed in a ball mill to obtain the pre-formed material; wherein, the preset raw material content of each layer is 92-98% by weight, the pretreated ultra-high strength steel powder is 1-4% by weight, the pretreated silicon carbide ceramic powder is 1-4% by weight, and the pretreated boron carbide ceramic powder is 1-4% by weight.

[0008] Step 3: Using argon as a protective gas, the pre-formed material layer is stacked onto the substrate to obtain the elevator safety clamp wedge composite material, specifically including:

[0009] Set the preheating temperature to 1600~1800℃ and the preheating time to 1~2h. Preheat the substrate and melt and form the first layer of preformed material on the preheated substrate to complete the preparation of the first layer of composite material.

[0010] The preheating temperature is set to 1700-1800℃ and the preheating time is 1.5-2h. The substrate is preheated, and the second preform is melted and formed on the first layer of the composite material to complete the preparation of the second layer of the composite material.

[0011] The preheating temperature is set to 1700-1800℃ and the preheating time is 1.5-2h. The third layer of preformed material is melted and formed on the second layer of composite material to obtain the elevator safety clamp wedge block composite material.

[0012] The above-mentioned method for preparing elevator safety clamp wedge composite material is characterized in that, in step one, the pretreatment specifically includes: placing the alloy steel material, silicon carbide ceramic powder and boron carbide ceramic powder in a high-temperature furnace at 120°C and drying them for 2 hours.

[0013] The method for preparing elevator safety clamp wedge composite material described above is characterized in that, in step one, the alloy steel material is spherical ultra-high strength steel powder with an average particle size <50μm, and the ultra-high strength steel powder is prepared by mixing the following raw materials in weight percentage: C 0.21-0.25%, Mn 0.01%, Si 0.1%, P 0.008%, S 0.005%, Cr 2.9-3.3%, Ni 11-12%, Co 13-14%, Mo 1.1-1.3%, Ti 0.015%, Al 0.015%, Fe balance; the silicon carbide ceramic powder has a SiC content >99% by weight and an average particle size <10μm; the boron carbide ceramic powder has a BC content >99% by weight and an average particle size <15μm.

[0014] The above-described method for preparing elevator safety clamp wedge composite material is characterized in that, in step two, the preset raw material content of each layer, by weight percentage, includes: 96-98% pretreated ultra-high strength steel powder, 1-2% pretreated silicon carbide ceramic powder, and 1-2% pretreated boron carbide ceramic powder; 94-96% pretreated ultra-high strength steel powder, 2-3% pretreated silicon carbide ceramic powder, and 2-3% pretreated boron carbide ceramic powder; and 92-94% pretreated ultra-high strength steel powder, 3-4% pretreated silicon carbide ceramic powder, and 3-4% pretreated boron carbide ceramic powder; the elevator safety clamp wedge composite material has three layers.

[0015] The method for preparing elevator safety clamp wedge composite material described above is characterized in that, before performing the lamination forming in step three, the pre-formed material from step two is dried to obtain the material to be laid.

[0016] The method for preparing elevator safety clamp wedge composite material described above is characterized in that the drying process specifically includes: placing the pre-formed material from step two into an oven at 120°C and drying it for 2 hours to obtain the material to be coated with powder.

[0017] The method for preparing elevator safety clamp wedge composite material described above is characterized in that, in the melting and forming of the first layer of preformed material, the laser power is 300-400W, the scanning interval is 0.1mm, the scanning rate is 900-1000mm / s, the layer thickness is 20μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0018] The method for preparing elevator safety clamp wedge composite material described above is characterized in that, in the melting and forming of the second layer of preformed material, the laser power is 400-500W, the scanning interval is 0.1mm, the scanning rate is 1000-1100mm / s, the layer thickness is 25μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0019] The method for preparing elevator safety clamp wedge composite material described above is characterized in that, in the melting and forming of the third layer of preformed material, the laser power is 500-600W, the scanning interval is 0.1mm, the scanning rate is 1100-1200mm / s, the layer thickness is 30μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. This invention provides a method for preparing a composite material for elevator safety clamp wedges. The method uses alloy steel, silicon carbide ceramic powder, and boron carbide ceramic powder as main raw materials. After pretreatment of the main raw materials, they are mixed and then baked and melted and stacked using a laser selective melting forming device to obtain the composite material for elevator safety clamp wedges. The composite material has good impact toughness, fatigue resistance, and wear resistance, which meets the performance requirements of safety clamp wedges.

[0022] 2. Preferably, the method includes mixing the pretreated raw materials according to the preset raw material content for each layer, and then using a laser selective melting forming equipment to form the melt layer under limited conditions. This can fully combine the excellent ductility, high fracture toughness, excellent fatigue and stress corrosion cracking resistance, high fatigue strength, excellent processing performance, good weldability, good polishing performance, and good strength and toughness matching of the ultra-high strength steel Aermet100 matrix, as well as the wear resistance of the silicon carbide ceramic and boron carbide ceramic reinforcing phases, thereby improving the comprehensive performance of the elevator safety clamp wedge block composite material.

[0023] 3. This invention creatively introduces a laser selective melting forming device to obtain an elevator safety clamp wedge composite material through melt layer stacking. From the working surface of the safety clamp wedge that rubs against the elevator guide rail to the fixed surface where the safety clamp wedge is fixed to the base, the hardness decreases layer by layer, while the impact toughness and fracture toughness increase layer by layer. The working part of the safety clamp wedge that rubs against the elevator guide rail has excellent friction and wear resistance and fatigue resistance, while the base part of the safety clamp wedge that is fixed to the base has excellent impact resistance and fracture toughness, which meets the performance requirements of the safety clamp wedge.

[0024] 4. Preferably, the method of the present invention further includes drying the material to be melted and stacked, which can effectively improve the flowability of the material to be laid and can directly form a non-standard elevator safety clamp wedge block composite material with high dimensional accuracy, good surface finish, higher density and fewer internal defects.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] Instruction manual illustrations

[0027] Figure 1 This is a metallographic photograph of the composite material of the elevator safety clamp wedge block in Example 1. Detailed Implementation

[0028] Example 1

[0029] This embodiment provides a method for preparing composite materials for elevator safety clamp wedges using laser selective melting technology, including the following steps:

[0030] Step 1: Pre-treat the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder separately, specifically including: drying the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder separately in a 120℃ high-temperature furnace for 2 hours; the alloy steel material is spherical ultra-high strength steel (Aermet 100) powder with an average particle size <50μm, and the ultra-high strength steel (Aermet 100) powder is prepared by mixing the following raw materials in the following weight percentages: C 0.21~0.25%, Mn 0.01%, Si 0.1%, P 0.008%, S 0.005%, Cr 2.9~3.3%, Ni 11~12%, Co 13~14%, Mo 1.1~1.3%, Ti 0.015%, Al 0.015, Fe balance; the silicon carbide ceramic powder has a SiC content >99% by weight and an average particle size <10 μm; the boron carbide ceramic powder has a BC content >99% by weight and an average particle size

[0031] <15μm;

[0032] Step 2: According to the preset raw material content of each layer of the elevator safety clamp wedge composite material, the pretreated alloy steel material, pretreated silicon carbide ceramic powder, and pretreated boron carbide ceramic powder are mixed in a ball mill to obtain a pre-formed material. The preset raw material content of each layer is as follows (by weight percentage): The first layer contains 98% pretreated ultra-high strength steel (Aermet100) powder, 1% pretreated silicon carbide ceramic powder, and 1% pretreated boron carbide ceramic powder; the second layer contains 96% pretreated ultra-high strength steel (Aermet100) powder, 2% pretreated silicon carbide ceramic powder, and 2% pretreated boron carbide ceramic powder; the third layer contains 94% pretreated ultra-high strength steel (Aermet100) powder, 3% pretreated silicon carbide ceramic powder, and 3% pretreated boron carbide ceramic powder. The elevator safety clamp wedge composite material has three layers.

[0033] Step 3: Place the pre-formed materials from Step 2 into an oven at 120℃ and bake for 2 hours to obtain the powder to be spread; this can effectively improve the flowability of the material during forming.

[0034] Step 4: Using a selective laser melting forming equipment with argon as the protective gas, the powder-laying and selective laser melting methods are used to stack the powder-laying material layer from Step 3 onto the substrate to obtain the elevator safety clamp wedge block composite material. Specifically, the selective laser melting forming equipment is a BLT-S320 selective laser melting forming equipment, purchased from Xi'an Bright Laser Technologies Co., Ltd.

[0035] Step 401: Set the preheating temperature to 1600℃ and the preheating time to 1h to preheat the substrate. Melt and shape the first layer of powder material to be laid onto the preheated substrate to complete the preparation of the first layer of composite material. During the melting and shaping of the first layer of powder material to be laid, the laser power is 300W, the scanning interval is 0.1mm, the scanning rate is 1000mm / s, the layer thickness is 20μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0036] Step 402: Set the preheating temperature to 1700℃ and the preheating time to 1.5h. Preheat the substrate after the preparation of the first layer of composite material in Step 1. Melt and shape the second layer of powder material to be laid onto the first layer of composite material to complete the preparation of the second layer of composite material. During the melting and shaping of the second layer of powder material to be laid, the laser power is 400W, the scanning spacing is 0.1mm, the scanning rate is 1100mm / s, the layer thickness is 25μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°. The first layer of composite material refers to the surface of the first layer of composite material away from the substrate.

[0037] Step 403: Set the preheating temperature to 1800℃ and the preheating time to 2h. Preheat the substrate prepared by the second layer of composite material in step two. Melt and shape the third layer of powder material to be laid on the second layer of composite material to obtain the elevator safety clamp wedge composite material. In the melting and forming of the third layer of powder material to be laid, the laser power is 500W, the scanning interval is 0.1mm, the scanning rate is 1200mm / s, the layer thickness is 30μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0038] The working principle of laser selective melting forming equipment includes: by controlling the laser beam and using a preset scanning path, raw material powder laid on a specific area of ​​the building platform is melted, and the material is melted and solidified layer by layer from bottom to top to form a three-dimensional solid part. Laser selective melting forming equipment typically consists of a laser system, a powder laying system, a building platform, a vacuum system, and a recovery system.

[0039] Figure 1 The image shows a metallographic photograph of the elevator safety clamp wedge composite material of Example 1. It can be clearly observed from the image that the composite material has a uniform microstructure, a dense structure, and no cracks, indicating that the elevator safety clamp wedge composite material prepared by the method of the present invention has an excellent microstructure.

[0040] In this embodiment, the elevator safety clamp wedge has a gradually decreasing hardness from the third floor to the first floor, from 420HB to 350HB, while its impact toughness and fracture toughness increase layer by layer, from 68J to 97J. This indicates that the elevator safety clamp wedge in this embodiment has the performance characteristics of gradually decreasing hardness and gradually increasing toughness from the working surface of the safety clamp wedge that rubs against the elevator guide rail to the fixed surface of the safety clamp wedge that is fixed to the base. This satisfies the excellent friction and wear resistance and fatigue resistance required for the working part of the safety clamp wedge that rubs against the elevator guide rail, and the excellent impact resistance and fracture toughness required for the base part of the safety clamp wedge that is fixed to the base, thus meeting the performance requirements of the safety clamp wedge.

[0041] Comparative Example 1

[0042] This comparative example is the same as Example 1, except that it does not undergo the drying process in step three, and the powder to be spread in step four is the pre-formed material in step two.

[0043] Comparative Example 2

[0044] This comparative example is the same as Example 1, except that in step one, the preset raw material content of each layer is 98% of the pretreated ultra-high strength steel (Aermet 100) powder, 1% of the pretreated silicon carbide ceramic powder, and 1% of the pretreated boron carbide ceramic powder.

[0045] The elevator safety clamp wedge in this comparative example maintains a relatively constant hardness from the third floor to the first floor, ranging from 352HB to 355HB. Its impact toughness and fracture toughness also remain relatively constant, ranging from 83J to 88J. This indicates that the elevator safety clamp wedge in this comparative example exhibits no gradient change in hardness or toughness from the working surface of the safety clamp wedge that rubs against the elevator guide rails to the fixed surface where the safety clamp wedge is fixed to the base.

[0046] Example 2

[0047] This embodiment provides a method for preparing composite materials for elevator safety clamp wedges using laser selective melting technology, including the following steps:

[0048] Step 1: Pre-treat the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder separately, specifically including: drying the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder separately in a 100°C high-temperature furnace for 2 hours; the alloy steel material is spherical ultra-high strength steel (Aermet 100) powder with an average particle size <50μm, and the ultra-high strength steel (Aermet 100) powder is prepared by mixing the following raw materials in the following weight percentages: C 0.21~0.25%, Mn 0.01%, Si 0.1%, P 0.008%, S 0.005%, Cr 2.9~3.3%, Ni 11~12%, Co 13~14%, Mo 1.1~1.3%, Ti 0.015%, Al 0.015, Fe balance; the silicon carbide ceramic powder has a SiC content >99% by weight and an average particle size <10μm; the boron carbide ceramic powder has a BC content >99% by weight and an average particle size <15μm;

[0049] Step 2: According to the preset raw material content of each layer of the elevator safety clamp wedge composite material, the pretreated alloy steel material, pretreated silicon carbide ceramic powder, and pretreated boron carbide ceramic powder are mixed in a ball mill to obtain a pre-formed material. The preset raw material content of each layer is as follows (by weight percentage): The first layer contains 97% pretreated ultra-high strength steel (Aermet100) powder, 1.5% pretreated silicon carbide ceramic powder, and 1.5% pretreated boron carbide ceramic powder; the second layer contains 95% pretreated ultra-high strength steel (Aermet100) powder, 2.5% pretreated silicon carbide ceramic powder, and 2.5% pretreated boron carbide ceramic powder; the third layer contains 93% pretreated ultra-high strength steel (Aermet100) powder, 3.5% pretreated silicon carbide ceramic powder, and 3.5% pretreated boron carbide ceramic powder. The elevator safety clamp wedge composite material has three layers.

[0050] Step 3: Place the pre-formed materials from Step 2 into an oven at 120℃ and dry for 2 hours to obtain the powder to be spread.

[0051] Step 4: Using a laser selective melting forming device with argon as the protective gas, the powder layer to be laid in Step 3 is stacked onto the substrate using powder spreading and laser selective melting methods to obtain the elevator safety clamp wedge block composite material, specifically including:

[0052] Step 401: Set the preheating temperature to 1750℃ and the preheating time to 1.5h to preheat the substrate. Melt and shape the first layer of powder material to be laid onto the preheated substrate to complete the preparation of the first layer of composite material. During the melting and shaping of the first layer of powder material to be laid, the laser power is 350W, the scanning interval is 0.1mm, the scanning rate is 950mm / s, the layer thickness is 20μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0053] Step 402: Set the preheating temperature to 1800℃ and the preheating time to 1.5h. Preheat the substrate after the preparation of the first layer of composite material in Step 1. Melt and shape the second layer of powder material to be laid onto the first layer of composite material to complete the preparation of the second layer of composite material. During the melting and shaping of the second layer of powder material to be laid, the laser power is 450W, the scanning interval is 0.1mm, the scanning rate is 1050mm / s, the layer thickness is 25μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°. The first layer of composite material refers to the surface of the first layer of composite material away from the substrate.

[0054] Step 403: Set the preheating temperature to 1700℃ and the preheating time to 1.5h. Preheat the substrate prepared by the second layer of composite material in step two. Melt and shape the third layer of powder material to be laid on the second layer of composite material to obtain the elevator safety clamp wedge composite material. In the melting and forming of the third layer of powder material to be laid, the laser power is 600W, the scanning interval is 0.1mm, the scanning rate is 1100mm / s, the layer thickness is 30μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0055] The metallographic structure of the elevator safety clamp wedge composite material in this embodiment is basically the same as that in Embodiment 1.

[0056] Example 3

[0057] This embodiment provides a method for preparing composite materials for elevator safety clamp wedges using laser selective melting technology, including the following steps:

[0058] Step 1: Pre-treat the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder separately, specifically including: drying the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder separately in a 120℃ high-temperature furnace for 2 hours; the alloy steel material is spherical ultra-high strength steel (Aermet 100) powder with an average particle size <50μm, and the ultra-high strength steel (Aermet 100) powder is prepared by mixing the following raw materials in the following weight percentages: C 0.21~0.25%, Mn 0.01%, Si 0.1%, P 0.008%, S 0.005%, Cr 2.9~3.3%, Ni 11~12%, Co 13~14%, Mo 1.1~1.3%, Ti 0.015%, Al 0.015, Fe balance; the silicon carbide ceramic powder has a SiC content >99% by weight and an average particle size <10μm; the boron carbide ceramic powder has a BC content >99% by weight and an average particle size <15μm;

[0059] Step 2: According to the preset raw material content of each layer of the elevator safety clamp wedge composite material, the pretreated alloy steel material, pretreated silicon carbide ceramic powder, and pretreated boron carbide ceramic powder are mixed in a ball mill to obtain a pre-formed material. The preset raw material content of each layer is as follows (by weight percentage): The first layer contains 96% pretreated ultra-high strength steel (Aermet100) powder, 2% pretreated silicon carbide ceramic powder, and 2% pretreated boron carbide ceramic powder; the second layer contains 94% pretreated ultra-high strength steel (Aermet100) powder, 3% pretreated silicon carbide ceramic powder, and 3% pretreated boron carbide ceramic powder; the third layer contains 92% pretreated ultra-high strength steel (Aermet100) powder, 4% pretreated silicon carbide ceramic powder, and 4% pretreated boron carbide ceramic powder. The elevator safety clamp wedge composite material has three layers.

[0060] Step 3: Place the pre-formed materials from Step 2 into an oven at 120℃ and dry for 2 hours to obtain the powder to be spread.

[0061] Step 4: Using a laser selective melting forming device with argon as the protective gas, the powder layer to be laid in Step 3 is stacked onto the substrate using powder spreading and laser selective melting methods to obtain the elevator safety clamp wedge block composite material, specifically including:

[0062] Step 401: Set the preheating temperature to 1800℃ and the preheating time to 2h to preheat the substrate. Melt and shape the first layer of powder material to be laid onto the preheated substrate to complete the preparation of the first layer of composite material. During the melting and shaping of the first layer of powder material to be laid, the laser power is 400W, the scanning interval is 0.1mm, the scanning rate is 900mm / s, the layer thickness is 20μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0063] Step 402: Set the preheating temperature to 1750℃ and the preheating time to 2 hours. Preheat the substrate after the preparation of the first layer of composite material in Step 1. Melt and shape the second layer of powder material to be laid onto the first layer of composite material to complete the preparation of the second layer of composite material. During the melting and shaping of the second layer of powder material to be laid, the laser power is 500W, the scanning spacing is 0.1mm, the scanning rate is 1000mm / s, the layer thickness is 25μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°. The first layer of composite material refers to the surface of the first layer of composite material away from the substrate.

[0064] Step 403: Set the preheating temperature to 1750℃ and the preheating time to 2h. Preheat the substrate prepared by the second layer of composite material in step two. Melt and shape the third layer of powder material to be laid on the second layer of composite material to obtain the elevator safety clamp wedge composite material. In the melting and forming of the third layer of powder material to be laid, the laser power is 600W, the scanning interval is 0.1mm, the scanning rate is 1100mm / s, the layer thickness is 30μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

[0065] The metallographic structure of the elevator safety clamp wedge composite material in this embodiment is basically the same as that in Embodiment 1.

[0066] Performance Evaluation

[0067] Friction and wear tests were conducted on the elevator safety clamp wedge composite materials in Examples 1-3 using a friction and wear testing machine. A load of 300 N was applied at a rotation speed of 1800 r / min. The test method was based on GB-T12444-2006, "Metallic Materials Wear Test Method". The wear amounts after 40 h, 60 h, and 80 h of wear are shown in Table 1. From the test data in Table 1, it can be observed that under the same friction and wear test conditions, the wear amount of the elevator safety clamp wedge composite material is much smaller than that of traditional elevator safety clamp materials. This indicates that the elevator safety clamp wedge composite material of the present invention has excellent wear resistance and fully meets the working environment requirements of elevator safety clamps.

[0068] Table 1. Test results of wear resistance of composite material for elevator safety clamp wedges

[0069] Traditional elevator safety clamp materials 145 176 198 Example 1 96 109 121 Comparative Example 1 112 125 141 Comparative Example 2 108 121 150 Example 2 93 104 116 Example 3 89 99 108

[0070] The conventional elevator safety clamp is made of 45 steel.

[0071] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a composite material for elevator safety clamp wedges, characterized in that, include: Step 1: Pre-treat the alloy steel material, silicon carbide ceramic powder, and boron carbide ceramic powder respectively; the alloy steel material is spherical ultra-high strength steel powder with an average particle size <50μm; the silicon carbide ceramic powder has a SiC content >99% by weight and an average particle size <10μm; the boron carbide ceramic powder has a BC content >99% by weight and an average particle size <15μm. Step 2: According to the preset raw material content of each layer of the elevator safety clamp wedge composite material, mix the pretreated alloy steel material, pretreated silicon carbide ceramic powder, and pretreated boron carbide ceramic powder in a ball mill to obtain the pre-formed material; wherein, the preset raw material content of each layer, by weight percentage, is 92-98% pretreated ultra-high strength steel powder, 1-4% pretreated silicon carbide ceramic powder, and 1-4% pretreated boron carbide ceramic powder; the preset raw material content of each layer, by weight percentage, includes the following for the first layer: pretreated ultra-high strength steel powder... The first layer contains 96-98% pre-treated silicon carbide ceramic powder and 1-2% pre-treated boron carbide ceramic powder; the second layer contains 94-96% pre-treated ultra-high strength steel powder, 2-3% pre-treated silicon carbide ceramic powder, and 2-3% pre-treated boron carbide ceramic powder; the third layer contains 92-94% pre-treated ultra-high strength steel powder, 3-4% pre-treated silicon carbide ceramic powder, and 3-4% pre-treated boron carbide ceramic powder; the elevator safety clamp wedge composite material has three layers. Step 3: Using argon as a protective gas, the pre-formed material layer is stacked onto the substrate to obtain the elevator safety clamp wedge composite material, specifically including: Set the preheating temperature to 1600~1800℃ and the preheating time to 1~2h. Preheat the substrate and melt and form the first layer of preformed material on the preheated substrate to complete the preparation of the first layer of composite material. The preheating temperature is set to 1700-1800℃ and the preheating time is 1.5-2h. The substrate is preheated, and the second preform is melted and formed on the first layer of the composite material to complete the preparation of the second layer of the composite material. The preheating temperature is set to 1700-1800℃ and the preheating time is 1.5-2h. The third layer of preformed material is melted and formed on the second layer of composite material to obtain the elevator safety clamp wedge block composite material.

2. The method for preparing elevator safety clamp wedge composite material according to claim 1, characterized in that, In step one, the pretreatment specifically includes: placing the alloy steel material, silicon carbide ceramic powder and boron carbide ceramic powder in a high-temperature furnace at 120°C and drying them for 2 hours.

3. The method for preparing elevator safety clamp wedge composite material according to claim 1, characterized in that, Step three, before the stacking process, also includes drying the pre-formed material from step two to obtain the material to be laid.

4. The method for preparing elevator safety clamp wedge composite material according to claim 3, characterized in that, The drying process specifically includes: placing the pre-formed materials from step two into an oven at 120°C and drying them for 2 hours to obtain the powder to be spread.

5. The method for preparing elevator safety clamp wedge composite material according to claim 1, characterized in that, In the melting and forming of the first layer of preformed material, the laser power is 300-400W, the scanning interval is 0.1mm, the scanning rate is 900-1000mm / s, the layer thickness is 20μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

6. The method for preparing elevator safety clamp wedge composite material according to claim 1, characterized in that, In the melting and forming of the second layer of preformed material, the laser power is 400-500W, the scanning interval is 0.1mm, the scanning rate is 1000-1100mm / s, the layer thickness is 25μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

7. The method for preparing elevator safety clamp wedge composite material according to claim 1, characterized in that, In the melting and forming of the third layer of preformed material, the laser power is 500-600W, the scanning interval is 0.1mm, the scanning rate is 1100-1200mm / s, the layer thickness is 30μm, the laser scanning strategy is checkerboard scanning, and the rotation angle between adjacent layers is 67°.

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