Basic Research On Remanufacturing Process Of Linear Guideway Based On Laser Cladding Technology

With the intensification of energy,resources and environmental constraints,the concept of green manufacturing has gradually become a global consensus.With the implementation of"Made in China 2025",it is required to vigorously develop the remanufacturing industry,implement high-end remanufacturing,intelligent remanufacturing,and in-service remanufacturing to promote the sustainable and healthy development of the remanufacturing industry.At the same time,the "13th Five-Year Plan" will incorporate remanufacturing into the development plan in accordance with the "Made in China 2025" plan.Continued government policy support has created a positive environment for the development of the remanufacturing industry.The popularization of laser cladding technology provides an effective solution for the remanufacturing of machine tool parts,which can effectively solve the problems of large energy consumption,serious environmental pollution and low repair rate of parts in traditional remanufacturing technology.Based on the Green Manufacturing System Integration Project of the Ministry of Industry and Information Technology of China,"Key Technologies and Application Demonstration of Machine Tool Green remanufacturing".In this paper,the Fe313 was selected as initial powder,the research object was to ensure the surface morphology,forming accuracy and the performance of the cladding layer,systematic experimental research and mechanism analysis were carried out,and it attempted to repair the linear guideway of machine tool.The main research contents of this paper include:(1)Based on Taguchi-Gray correlation analysis,the laser cladding parameters were optimized to achieve multi-parameter optimization under multi-objective response.Taking the linear guideway material(S55)as the base,the Fe313 was selected as the cladding powder,and the laser power,scanning speed and powder feeding speed were selected as the process parameters to be optimized,and the cladding width,cladding height and dilution ratio were selected as the response targets to be optimized.A 3-factor and 5-level orthogonal experiment was designed by using the Taguchi method.The variance of the signal-to-noise ratio(SNR)of the three-response target was analyzed.The magnitude and order of each factor's influence on the response target were analyzed.Based on the gray correlation analysis of Taguchi method,the three response targets were transformed into individual gray correlation degree to optimize the process parameters,and find the best combination of process parameters that can achieve the maximum cladding width,minimum cladding height and suitable dilution rate.Finally,the prediction of gray correlation degree and the improvement of response target were verified by experiments.At the same time,for overlapping rate and ?Z in multi-track single-layer and multi-track multi-layer,single-objective optimization was performed by gradient search.(2)In order to enhance the wear resistance of Fe-based cladding layer,TiN,Ti and graphite were added into the initial Fe313 powder,and Ti(C,N)ceramic reinforcing phase was in-situ synthesized by laser cladding Firstly,the thermodynamic calculation was used to judge whether the chemical reaction can occur spontaneously.The reaction mechanism was explored by adding different ratios of phases in 5 groups.After cladding,the energy spectrum and phase analysis of the cladding layer with different addition amounts by SEM,EDS and XRD,the wear resistance was analyzed by the friction and wear test,and scratch test was carried out on the cladding layer to obtain the strength of the deformation resistance of the cladding layer.(3)To characterize the effect of heat treatment at different temperatures on the microstructure and mechanical properties of Ti(C,N)reinforced iron-based coatings and the machinability of heat-treated coatings.Differential scanning calorimetry(DSC)was used to analyze the powder and to guide the setting of heat treatment temperature of cladding layer.The microstructure,tensile strength and bending strength of cladding layers treated at different temperatures were tested,and the effects of different heat treatment temperatures on the cutting performance of cladding layers were studied,including milling force,surface roughness and vibration during milling.Finally,the failure modes of the linear guideway are observed,the upper raceway surface,the lower raceway surface and the 45° inclined surface of the linear guide were pretreated,and finally the surface of the linear guide was repaired.