The image above shows tick mars in a line chart, there are two types of tick marks, major and minor tick marks. The chart above shows only major tick marks and the chart below displays both major and minor tick marks on both the x-axis and y-axis.
How to add chart axis tick marks
Right click on an axis.
Click on "Format Axis..."
Click on "Axis Options" button.
Expand "Tick Marks".
Change "Major Type" to Inside.
You have three options, tick marks inside, outside or cross. Above picture displays inside tick marks.