Is it possible to compleately and utterly brick a phone with no chance of repair? As i have recently gotten into some research about android kernel development and would like to fiddle around my phone and of course i have seen all the warnings about "bricking your device" but it seems like most of the issiues i could encounter could be fixed by flashing the stock kernel onto the phone.

But i am very inexperianced in this field and would really like someone else's opinion on the matter.

So is it possible to compleately break the bootloader and destroy the device and if it is how would work so i can avoid it?

PS: I appologize if the question is too broad but any input on the matter is appreciated
Most bricks are "soft" bricks, where the device will not boot but can be fixed by flashing good software.

To fix "hard" bricks requires special tools (like a JTAG setup or USB jig) that are not generally available to end users.  (And yes, it is possible to do this.)

It is also possible to unrecoverably fry the chips on the device, and this could potentially result from kernel development (overclocking and reaching unsafe temperatures, for example).