Laser cladding machine refers to the use of high-energy laser beams to irradiate the metal surface, through rapid melting and cooling, cladding a layer of material with special physical, chemical or mechanical properties on the surface of the substrate to form a new composite material.
In the development process of laser cladding technology, choosing the right cladding powder material is very critical to the quality of the cladding product. Because the choice of cladding powder material will directly affect the performance of the laser cladding layer.The laser cladding powder material is completely or partly melted under the high temperature action of the laser to form a laser molten pool, and the cladding layer is formed immediately after solidification. In order to improve the quality of the cladding layer, the cladding material must meet the following requirements:
1. Good Performance: The selected powder material must be able to meet the requirements of the surface conditions of the parts, such as wear resistance, corrosion resistance, high temperature resistance, oxidation resistance, and electrical conductivity.
2. Good Chemical Stability and Thermal Stability: When the coefficient of thermal expansion between the cladding material and the substrate is too large, the rapid heating and cooling in the laser cladding process will cause uneven shrinkage, resulting in a large thermal stress, which will cause the coating to peel off from the substrate or crack.
3. Better Wettability: The cladding material should have good wettability with the substrate in the molten or semi-molten state to ensure good bonding performance between the coating and the substrate.
4. Better Liquidity: When the coating material is powder, its shape, particle size distribution, and surface condition should meet the requirements, and it must have good fluidity, so that a good uniform coating can be obtained. When the coating material is rod or wire, it should have good forming performance, and have a certain strength, and the particle size value should be uniform and accurate.
The metal powders used in laser cladding mainly include: tool steel, martensitic steel, stainless steel, pure titanium and titanium alloys, aluminum alloys, nickel-based alloys, copper-based alloys, cobalt-chromium alloys, etc. The most studied laser cladding materials, and the most widely used is nickel-based self-fluxing alloy powder. It has wettability, wear resistance and high temperature self-lubricating properties. It can choose nickel-based powders of different chemical compositions and grades according to the requirements of wear resistance. The nickel-based cladding layer prepared by laser cladding is widely used in molds, cast iron, nickel alloy, steel, stainless steel parts, crankshafts, rolls, bushings, bearing seats, eccentric wheels and other parts.
In general, nickel-based alloys have good tensile, fatigue and thermal fatigue resistance. At present, there are mainly Inconel 738, Hastelloy X, Inconel 625, Inconel 713, Inconel 718 and other models. Inconel 738 has good high temperature creep rupture strength and hot corrosion resistance, and is a super alloy with a lower chromium content. It can be exposed to high temperature and corrosive environment up to 920-980℃ for a long time, and is suitable for the cladding of aircraft engines and gas turbines. Hastelloy X has high strength and oxidation resistance at high temperatures, and also has good ductility in environments up to 1200°C. At present, it is mainly used in aerospace technology and industrial furnaces, petrochemical and chemical process industries. Inconel 625 still has good load performance at a high temperature of about 815°C, and has strong corrosion resistance. It is widely used in aerospace, chemical and power industries.
By choosing the cladding powder material that matches the base material, the potential of the material can be maximized. This can not only improve the performance of the workpiece and shorten the manufacturing cycle of the product, but also obtain significant economic benefits.
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.
Source link: https://www.sfcnclaser.com/how-to-choose-laser-cladding-powder-materials.html