Laser cladding technology is a material surface modification technology that has developed rapidly in recent decades. It has excellent characteristics that many conventional technologies cannot achieve, such as low requirements for the working environment, small deformation of the workpiece after processing, and obtaining a high-hardness surface modification layer.Therefore, laser cladding is being valued by more and more research institutions and enterprises. At present, the use of laser cladding machine to cladding a cermet layer on the surface of the steel cutter to improve the performance of conventional steel cutters has been widely used.
High-speed steel cutters have become a widely used tool in the machining industry because of their good machinability. The annealing temperature of high-speed steel is generally about 860~880℃, but when processing some materials with higher hardness, the cutting temperature is often very high (about 1000℃), which will cause the hardness of the steel cutter to decrease and fail to meet the processing requirements.In the cutting process, the steel cutter has to withstand the impact and vibration load, and at the same time, it is also subject to the strong friction of the workpiece. As a result, high-speed steel cutters often appear wear, curling, chipping or breaking during use. It affects the machining accuracy and production efficiency, shortens the service life of the tool, and increases the production cost at the same time.
At present, the commonly used high-speed steel cutters are generally scrapped when the cutting edge is worn. Therefore, the material waste of the steel cutter is extremely large and the manufacturing cost is high.However, laser cladding equipment can add cladding material to the cutting edge of the steel tool to enhance the cutting edge band of the tool. Through laser metal deposition, expensive metal materials can be saved, thereby reducing manufacturing costs. At the same time, the cutting edge of the tool after cladding has higher strength, hardness and wear resistance, but also has the strength and toughness of the matrix, which better solves the contradiction between the hardness and toughness of the high-speed steel tool, and improves the cutting performance of high-speed steel cutters.
However, in the laser cladding process, the main problem is that the cladding layer is prone to cracks. The main reason is that the cladding layer forms internal stress due to the constraints of the matrix when it cools and solidifies and shrinks. When the local internal stress exceeds the strength limit of the material, cracks will occur. In order to reduce the occurrence of cracks, the following measures can be taken: first, preheat and post heat treatment of high-speed steel tools to reduce the temperature gradient between the cladding layer and the substrate. Secondly, some ingredients that play the role of bonding phase can be added to the alloy powder, such as Co, Mo and rare earth. The addition of Co and Mo can improve the wettability of the alloy, which is beneficial to reduce the thermal shrinkage stress of the cladding layer during the condensation process; the rare earth refines the structure of the alloy layer and improves the toughness, thereby reducing the occurrence of cracks. In addition, optimization of alloy powder formula and laser process parameters and the use of nano composite powder can improve the performance of the cladding layer and reduce cracks.
Combining the advantages of laser cladding technology with the requirements for high-speed cutting tools in cutting processing can make high-speed steel cutting tools have excellent processing properties such as wear resistance, heat resistance, corrosion resistance, high temperature oxidation resistance and higher red hardness.In addition, less powder materials are consumed in the laser cladding process, which meets the requirements of energy saving and environmental protection. And the process is simple, the required equipment is less, and it is easy to realize automation.
As a laser cladding machine manufacturer, Jinan Senfeng Laser Technology Co., Ltd. has a professional team to design and develop laser cladding machines. If you want to know more about laser cladding machine, please contact SENFENG LEIMING.
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