Farming these in EA's is extremely time consuming, its a very rare drop, and generally u need to do it in HM.
Your other options are:
>Buy them outright from the Rare Materials Traders
>Buy them from players selling them, if u can find any
>Do some faction-based farming by VQ'ing Luxon held areas and turning in the faction to a Luxon Scavenger
>Do JQ and use ur Imperial Faction to make Luxon faction and turning in the faction to a Luxon Scavenger
And that's that,