De or het magnesiumlegering?

The correct Dutch article is:

de magnesiumlegering

Rule Words ending in -ing: almost always de. See the rule

How to use magnesiumlegering

the magnesiumlegeringde magnesiumlegering
this magnesiumlegeringdeze magnesiumlegering
that magnesiumlegeringdie magnesiumlegering
our magnesiumlegeringonze magnesiumlegering
your magnesiumlegeringjouw magnesiumlegering
every magnesiumlegeringelke magnesiumlegering
which magnesiumlegering?welke magnesiumlegering?
a big magnesiumlegering / the big magnesiumlegeringeen grote magnesiumlegering, de grote magnesiumlegering