Research On The Bonding Properties Of ZChSnSb/FeSn₂/steel Composites

The oil-film bearing bush is the core component of many kinds of equipment,and its quality is very important for the safe operation of the equipment.The production of traditional oil-film bearing bushing is centrifugal casting technology which is a combination of Babbitt alloy and tin plated steel,and its process complexity leads to larger production cost.With the development of welding technology,the Babbitt alloy can be directly connected with the steel body through welding.Therefore,it is of great significance to the experimental and theoretical study of the bonding mechanism of the Babbitt alloy and the steel body under the welding process.The main contents of this paper are as follows:Firstly,according to the ISO 4386-2-2012 standard,the bimetallic bonding strength specimens of the bearing under the welding process were designed and fabricated,and the specimens were tested by SEM,EDS and XRD.Through the analysis of microstructure,element distribution and mass distribution of the bonding interface,it is concluded that the transition layer is about 11.5?m when combined with the steel body during the Babbitt welding process.The main elements of the transition are Sn,Fe and Sb.Through the XRD test,it is confirmed that the transition layer is mainly composed of compounds FeSn₂ and a small amount of SnSb.The unit cell parameters of the main material of the bonding interface between Babbitt alloy and steel are measured,which provides necessary parameters for building the molecular dynamics model.Secondly,based on the measured unit cell parameters,three different transition layer material models are established using Materials Studio.Based on Newton-Raphson methods for model energy and geometric optimization,the molecular dynamics simulation analysis is carried out,and the calculation formula of three layers composite material bonding energy is derived.The lager interface bonding energy of the three models is the transition layer FeSn₂.The model of ZChSnSb/FeSn₂/Steel was simulated under different temperatures,and the result shows that the best combination of Babbitt alloy and steel body temperature is 512K;in addition,different thickness of FeSn₂ on the ZChSnSb/FeSn₂/Steel model is simulated when the transition layer is 15.396A.Finally,a complete formula of the singular stress field at the interface end of the composite is derived.By calculating the Dundurs parameters of the singular stress field at the interface end of the composite material and the related parameters,the stress field of the composite with different materials is calculated.The singularity stress of the ZChSnSb and FeSn₂ is less than the singularity of other steel materials.The singularity stress is calculated when FeSn₂ is combined with different steel bodies.It is concluded that when the base material is 20 steel,the singularity stress is the smallest.A cell model combined with three different steel bodies is constructed respectively,and the bonding energy is calculated,and the bonding energy is maximum when the matrix material is 20 steel.The combination of the three kinds of steel and the Babbitt alloy is prepared,and the tensile shear test of the specimens is obtained,and the tensile shear strength of the same 20 steel is the largest.In summary,the theoretical calculation and the molecule are obtained.The comprehensive results of dynamic simulation and strength failure test show that 20 steel is more suitable for the oil-film bearing bushing as compared with the 30 steel and the40 steel.