The Issue of Marriage with a Slave Woman
20-11-2018 | IslamWeb
Question:
Asalamu AleikumIs it necessary to marry a slave (woman) in order to have intercourse with her?
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
Asking a question on the ruling of marriage with slave women at this time has no basis, because the issue of slavery does no longer exist.
Therefore, the existence of a slave woman is not available now.
However, we will explain to the questioner the Sharee'ah ruling on the issue of a free man marrying a slave woman. The jurists agreed that it is permissible for him to marry a slave woman if he is not financially able to marry a free woman while he fears to commit Zina (fornication).
The Kuwaiti Fiqh Encyclopedia reads:
"The jurists agreed that it is permissible for a man to marry a Muslim slave woman if he is not financially able to marry a free woman, and he fears to commit illegal sexual intercourse (i.e. Zina). Ibn Qudaamah 
said: 'This is the view of most scholars and there is no difference of opinion between them.'"
The principle about this is the Saying of Allah (which means): {And whoever among you cannot [find] the means to marry free, believing women, then [he may marry] from those whom your right hands possess of believing slave girls. And Allah is most knowing about your faith. You [believers] are of one another. So marry them with the permission of their people and give them their due compensation according to what is acceptable. [They should be] chaste, neither [of] those who commit unlawful intercourse randomly nor those who take [secret] lovers. But once they are sheltered in marriage, if they should commit adultery, then for them is half the punishment for free [unmarried] women. This [allowance] is for him among you who fears sin, but to be patient is better for you. And Allah is Forgiving and Merciful.} [Quran 4:25] [End of quote]
Allah knows best.