Checking in a u-haul box on an international flight

We're moving from the US to India and will be flying Qatar Airways (with 1 stop over in Qatar). We're a family of 4 and are allowed 2 checked in luggage items per person. We don't own 8 suitcases so I was wondering if I can check-in a few uhaul boxes instead. We will follow the weight limit and tape up the boxes all over so they don't open up or fall apart during the journey. Does anyone know if this is allowed? Specifically, I am wondering what might happen if tsa/customs open up the box to check its contents.