# Prediction of Cutting Parameters of HVOF-Sprayed Stellite 6
## 3 Experimental Work
### Adhesion \(A_{dlnp}\) of the Coating Material on the Substrate  
The adhesion of the coating material on the substrate (Table 6), sufficiently discretely expressed by choice of cutting parameters, can be calculated according to the newly derived relation (52):  
\[A_{dlnmp}=k_{adh}\cdot 10^{-5}\cdot\frac{Ra_{mp}}{D_{gr}}\cdot E_{mat} \tag{52}\]  
The constant \(k_{adh}\) [-] serves for practical calculations for the roughness compensation \(Ra\) from the machined surface to the technologically required level. There are cases in which the roughness \(Ra\) needs to be reduced or increased to achieve higher adhesion forces between substrate and coating/spray. Constant \(k_{adh}\) also defines precisely how to edit the cutting parameters.  
The optimization of the choice of cutting parameters for the most suitable roughness of the substrate according to the actual grain size of the coating/spraying can be done by using Table 1 to select the most appropriate combination of cutting parameters according to the adhesion and technological application condition requirements for the selected Section along the (x) axis, where (x) are the discrete values \(W_{p}\) = f (\(E_{xpNO}\))  
A more detailed analysis can then be carried out by adding the functions mentioned above to other functions, namely the discretely determined adhesive tension \(A_{dhmp}\) and cutting force \(F_{c}\), the \(k_{adh}\) proportionality constant and other selected functions according to the implicit relationship (\(A_{dhmp}\), \(F_{c}\), \(k_{adh}\),...) = f (\(R_{mp}\), \(E_{\gamma nNO}\)). The calculation applies to materials in general and can, therefore, be implemented separately for each type of substrate, coating/spraying. The graphs for the studied steel EN S235 JRG1/Stellite, Stellite/Stellite and Stellite/Carbide WC-Co here are located under Table 6 and in Figures 7 and 8. In Tables 7 and 8 parameters for the experiment numbers \(E_{xpNO}\) = 1-28 are selected, measured, and calculated.  
Figure 10: Comparison of working parameters LOG f (\(W_{p}\)) = f (\(E_{x\text{pNO}}\)) for Stellite 6, where: Section A (\(E_{x\text{pNO}}\) 1–6) insufficient roughness for the desired adhesion, Section B (\(E_{x\text{pNO}}\) 6–21) very good roughness for the desired adhesion, Section C (\(E_{x\text{pNO}}\) 21–24) sufficient roughness for the desired adhesion.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**E\({}_{\text{spNo}}\)** & **Unit** & **1** & **10** & **19** & **28** \\ \hline \(D_{grA}\) & \(\mu\)m & 0.004 & 0.021 & 0.051 & 0.364 \\ \(D_{grB}\) & \(\mu\)m & 0.009 & 0.057 & 0.179 & 1.818 \\ \(D_{grC}\) & \(\mu\)m & 0.076 & 1.654 & 13.821 & 34.187 \\ \(h_{\text{dscA}}\) & mm & 0.220 & 1.654 & 1.552 & 5.451 \\ \(h_{\text{dscB}}\) & mm & 0.217 & 0.915 & 1.445 & 4.324 \\ \(h_{\text{dscC}}\) & mm & 0.203 & 0.703 & 0.979 & 1.782 \\ \(\sigma_{A}\) & MPa & 751.92 & 1227.86 & 1029.34 & 1492.50 \\ \(\sigma_{B}\) & MPa & 865.08 & 1412.66 & 1184.26 & 1717.10 \\ \(\sigma_{C}\) & MPa & 1225.11 & 2000.59 & 1677.13 & 2431.80 \\ \(S_{c}\) & mm\({}^{2}\) & 0.045 & 0.045 & 0.046 & 0.100 \\ \(F_{cA}\) & N & 33.84 & 55.25 & 47.35 & 191.20 \\ \(F_{cB}\) & N & 38.93 & 63.57 & 54.48 & 220.00 \\ \(F_{cC}\) & N & 55.13 & 90.03 & 77.15 & 311.50 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Continued Table 6 for \(D_{gr}\), \(h_{\text{dsc}}\), \(\sigma\), \(F_{c}\) (\(E_{x\text{pNO}}\) = 1, 10, 19, 28).  
Figure 9: Comparison of working parameters LOG f (\(W_{p}\)) = f (\(E_{x\text{pNO}}\)) for EN S235 JRG1, where: Section A (\(E_{x\text{pNO}}\) 1–6) insufficient roughness for the desired adhesion, Section B (\(E_{x\text{pNO}}\) 6–13) very good roughness for the desired adhesion, Section C (\(E_{x\text{pNO}}\) 13–24) sufficient roughness for the desired adhesion.