# Grain Orientation and Hardness in the Graded Interlayer of Plasma Sprayed W on CuCrZr
## 3 Results and Discussion
This index takes into account the ratio between the intensity of a given peak and that of the highest peak in the examined and reference materials. In \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Tungsten**} & \multicolumn{6}{c}{**Copper**} \\ \hline  & **(110)** & **(200)** & **(211)** & **Texture** & & **(111)** & **(200)** & **(220)** & **Texture** \\ \hline W-4-806 & 100 & 15 & 23 & Random & Cu-4-836 & 100 & 46 & 20 & Random \\ Substrate & - & - & - & - & Substrate & 60 & 66 & 100 & \textless{}110\textgreater{} \\ \(1/(125\)\(\upmu\)m) & - & - & - & - & \(1/(125\)\(\upmu\)m) & 33 & 100 & 86 & \textless{}110\textgreater{} \\ \(2/(375\)\(\upmu\)m) & - & - & - & - & \(2/(375\)\(\upmu\)m) & 31 & 97 & 100 & \textless{}110\textgreater{} \\ \(3/(625\)\(\upmu\)m) & 100 & - & - & \textless{}110\textgreater{} & \(3/(625\)\(\upmu\)m) & 88 & 88 & 100 & \textless{}110\textgreater{} \\ \(4/(875\)\(\upmu\)m) & 100 & 20 & 30 & \textless{}211\textgreater{} & \(4/(875\)\(\upmu\)m) & 100 & 47 & 46 & \textless{}110\textgreater{} \\ \(5/(1125\)\(\upmu\)m) & 100 & 22 & 40 & \textless{}211\textgreater{} & \(5/(1125\)\(\upmu\)m) & 100 & 67 & 18 & \textless{}110\textgreater{} \\ W coating & 100 & 12 & 13 & \textless{}110\textgreater{} & W coating & - & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The relative intensities of the W and Cu diffraction peaks in the XRD patterns collected from the CuCrZr substrate, W coating, and five different zones of the interlayer. The distance from the substrate of the interlayer’s irradiated zones is reported in brackets. For each zone, the central position of the X-ray spot is indicated. Figure 6: XRD patterns collected in the CuCrZr substrate, W coating, and five different zones along the interlayer. the case of Cu, the index of the \(<\)100\(>\) texture component is \((I_{200}/I_{111})/(I_{200}/I_{111})_{R}\) while that of the \(<\)110\(>\) texture component is \((I_{220}/I_{111})/(I_{220}/I_{111})_{R}\). The subscript \(R\) indicates a random orientation. For W \((I_{200}/I_{110})/(I_{200}/I_{110})_{R}\) and \((I_{211}/I_{110})/(I_{211}/I_{110})_{R}\) describe the \(<\)100\(>\) and \(<\)211\(>\) texture components, respectively. Of course, if the grains have a full random grain orientation, the index is 1 for each texture component. Figure 7 shows the texture index of Cu (a) and W (b) in the examined zones calculated from the data in Table 2.  
The CuCrZr substrate has a principal \(<\)110\(>\) texture and a secondary \(<\)100\(>\) cubic component. In the first deposited layers of Cu (zones 1 and 2), these texture components become even stronger; subsequently, starting from a distance of \(\sim\)500 \(\upmu\)m, they progressively weaken, and finally the Cu grains take on an almost random orientation near the coating (zones 4 and 5). The XRD patterns of W collected from zones 1 and 2 exhibit only a very weak (110) peak with intensity comparable to the background; thus, they are not suitable for describing a possible texture. In the zones 4 and 5 and the coating, the relative intensities do not  
Figure 7: Index describing texture components of Cu (a) and W (b) in the seven examined zones. significantly diverge from those corresponding to the random grain orientation; only weak <100> and <211> texture components were observed there. The dislocation density of Cu and W in the different zones was determined from the analysis of the XRD peak profiles, namely from their half-height line widths. The Cu peaks recorded in different positions of the interlayer were shown to be quite similar, whereas those of W exhibited different broadening, depending on the specific position. For example, Figure 8 shows the Cu (220) and W (211) peaks collected in different positions in the interlayer. To better compare the broadening of the peaks, they were suitably shifted to occupy the same central position.