Blaze by Clarissa Lake

Blaze Savage, a cyborg marine ranger, fought in an interstellar war for ninety years. Captured and tortured by the enemy, he had wished for death in the darkest times.
The promise of her, the one female who was his genetic complement with whom he could breed and make a family, kept him from giving up. It was the promise of love embedded in their programming. But there was no plan for the cyborgs’ happy ending when the war was over.
Needing time to decompress after the war, Blaze went to the cyborg planet Phantom. But he knew he wouldn’t find her on a world with hardly any females.
When Commander Vyken Dark needed a team of rangers to bring law and order to the west, Blaze was ready to start the next part of his life on Earth, where he is already in the database of females looking for cyborg mates.
But fate steps in, and Blaze finds her running from a man who claims she belongs to him…