Dear Ankit,

You can go for high energy synchrotron radiation. Here you can do simultaneous determination of all crystalline phases of a material within one experiment under a fixed diffraction angle. 

Or

Based on experimental data available, you can go for SEM and microscope microanalyzer.

Nanoindentation and nanoscratch techniques are suitable techniques for grain boundary analysis. Please go through some references for more details about these techniques. 

Based on experimental data available, you can go for SEM [scanning electron microscope] and Image anlyser

by simple optical microscopy and by SEM.