Couple of quick points.
It looks to be a 3 Series Aluminum(very soft and Malleable), and this is quite common with that grade of Aluminum.
You need to Check your Speed and Feeds(look at chip tooth loading and depth of cuts),
however I think Climb Milling may get rid of the Chip extrusion, provided you clear the chip
path by using a brush or Air between each Cut. If you can try hooking up a blast misting arrangement, it will clear the
chips and lubricate and cool at the same time.
Wes