粉末粒径与工艺参数对NbC熔覆层组织与性能的影响研究

Study on the influence of powder size and process parameters on the microstruc‐ture and properties of NbC cladding layer

通过制备不同粒径的Nb和B4C颗粒,在45钢表面原位合成NbC,旨在研究不同粒径与工艺参数对复合涂层组织演变和显微硬度的影响。采用响应面法中心复合设计模块分析粉末粒径、激光功率、扫描速度和气流量对复合材料熔覆层性能的影响关系,建立工艺参数与熔覆层硬度之间的数学模型,通过方差分析和模型检验,验证了模型的准确性。研究发现,改变粉末粒径不会改变熔覆层的相组成,但熔覆层的硬度随着激光功率和粉末粒径的增加而增大,随着扫描速度与气流量的增加而减小。以熔覆层硬度最大为目标进行优化,预测值与实际值的误差率为1.4%。该研究成果为熔覆层性能的预测与控制提供理论依据。

In this study,Nb and B4C particles with different particle sizes were prepared on 45 steel surface to synthesize NBC in situ.The effect of different particle size and process parameters on the microstructure evolu‐tion and microhardness of the composite coating was studied.The central composite design module of response surface method was used to analyze the influence of powder particle size,laser power,scanning speed and gas flow rate on the performance of composite cladding layer,and the mathematical model between process parame‐ters and cladding layer hardness was established.The accuracy of the model was verified by variance analysis and model test.It is found that the phase composition of the cladding layer is not changed by changing the parti‐cle size of the powder,but the hardness of the cladding layer increases with the increase of the laser power and the particle size of the powder,and decreases with the increase of the scanning speed and the gas flow rate.The error rate between the predicted value and the actual value is 1.4%.The research results provide a theoretical ba‐sis for the prediction and control of cladding layer performance.