Liquimetal Coating

{T}: Target permanent becomes an artifact in addition to its other types until end of turn.

Seal of Primordium

Sacrifice Seal of Primordium: Destroy target artifact or enchantment.

Viridian Shaman

When Viridian Shaman enters, destroy target artifact.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Tribute Mage

When Tribute Mage enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Memnarch

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)
{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

Oxidize

Destroy target artifact. It can't be regenerated.

Neurok Transmuter

{U}: Target creature becomes an artifact in addition to its other types until end of turn.
{U}: Until end of turn, target artifact creature becomes blue and isn't an artifact.

Trygon Predator

Flying
Whenever this creature deals combat damage to a player, you may destroy target artifact or enchantment that player controls.