RECOMMENDATIONS
There are two most critical parts for this project. First, the images of (square)
indentation which determine the hardness of the ceramic at that spot in microstructure
and second, the slopes of 2 trend-lines which have been proved the ceramic from EBPVD is stronger than APS’s in figure XYZ. The result for this project can be more
interesting with clearer microstructures images of cracks and indentations. Importantly,
the slopes of trend-lines in figure XYX (last page of CHAPTER – RESULTS &
DISCUSSION) can be more accurate with more data points. Following are two
recommendations:
1. Microscope:
The images of cracks and indentations will be presented more accurate and better
if there is another microscope available. There was a 1000x magnifier but it does
not work properly.
2. Vickers Micro Hardness Tester:
The minimum built-in-load-applied for indenter is 25gf. The next load steps are
50gf, 100gf, 200gf, 300gf, etc, and 1000gf as the maximum. In this experiment,
ceramic from Air Plasma Spray process and Electron Beam Physical Vapor
Deposition process has only 3 data sets of crack length from 3 load steps; 25gf,
50gf and 100gf (ceramic is crushed under 200gf-load). The crack’s progression
of ceramic from each process above will be observed clearly with more smaller
load steps:

If the tester has more load steps with 25gf increment such as 25gf, 50gf,
75gf, 100gf, 125gf, 150gf, 175gf, etc.

If the tester stars from a minimum load that is smaller than 25gf with 5gf
increment such as 5gf, 10gf, 15gf, etc.