Ti/TiBCN composite coatings were prepared on a 7075 aluminum alloy surface by laser cladding. The relation between the main processing parameters (i.e., laser power, scanning speed, and powder feeding rate) and the geometrical characteristics (i.e., height, width, penetration depth, dilution and wetting angle) of single clad tracks is studied by linear regression analysis. The microstructure, micro-hardness and electrochemical corrosion were investigated by scanning electron microscopy, a Vickers micro-hardness machine, and a standard three-electrode cell, respectively. The results showed that all geometrical track characteristics are observed with high values of the correlation coefficient (R > 0.95). In addition, the average hardness value (750 HV_0.2) was obtained of the Ti/TiBCN composite coating, and polarization curves indicated that the composite coatings were harder to corrode than the substrate.

In order to realize a better description of plastic flow behavior in the warm deformation process of GH4149, the GH4169 superalloy was compressed by Gleeble-3800 at a temperature of 700–900 °C and a strain rate of 0.01–10 s⁻¹. The constitutive model of GH4169 superalloy was established using artificial neural network (ANN) and the Arrhenius equation, and the accuracy of the model was compared. The results show that the average absolute relative error (AARE) of the ANN constitutive model is 4.34%. The AARE of the Arrhenius equation constitutive model is 29.95%. The ANN constitutive model is more accurate than the Arrhenius constitutive model, and has consistent accuracy in the whole parameter range. The stress–strain curve obtained by the model is in good agreement with the experimental curve. The process of the warm compression test is simulated by finite element software importing the ANN constitutive material model. The results verified the reliability of the model. The ANN constitutive model can effectively predict the flow stress of GH4169 superalloy during the warm deformation process.

The warm deformation behavior of 65Mn spring steel has been carried out by a thermomechanical simulator. The deformation temperatures are in the range of 550 ~ 700℃ and strain rates are in the range of 0.001 ~ 1 s^-1. The deformation activation energy is calculated to be 486.829 KJ•mol^-1. The strain compensated Arrhenius-type constitutive model was established. The relationship materials constants and strain were fitted with an 8th order polynomial. It was found that the strain has a significant influence on the instability map. At the strain is 0.3, the optimum flow zone may take place with the deformation temperatures higher than 626 ℃ and strain rate in the range of 0.001 ~ 1 s^-1.

Manganese phosphate conversion coatings were prepared on 65Mn spring steel. The surface morphologies and compositions of the coatings were examined through scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion resistance of the coatings was investigated using a copper sulfate titration experiment, salt spray test and electrochemical corrosion test. The results showed that a uniform and dense coating was obtained when the acid ratio was 10, the phosphating temperature was 85 °C, and the phosphating time was 5 min. There was no obvious rust on the manganese phosphate coating surface after 48 h of salt spray. Ultimately, the growth mechanism and corrosion behavior of the manganese phosphate conversion coating are explained.