The phrase "are gradually converted to" is correct and usable in written English.
It can be used when describing a process of change or transformation that occurs over time.
Example: "As technology advances, traditional methods of communication are gradually converted to digital formats."
Alternatives: "are slowly transformed into" or "are progressively changed to".
Many of those remaining in the homeland were gradually converted to Roman Catholicism.
Metallic antimony is not affected by air or moisture under ordinary conditions, but it is gradually converted to an oxide if the air is moist.
As a youth player, he developed as a defensive midfielder but was gradually converted to central defense, where he now feels most comfortable.
Once Claire is living on the ranch, she is gradually converted to both hard work and love of the land, and like many converts, she comes to embrace her new faith much more deeply than those born to it.
In Sumatra and Java, whose populations were gradually converted to Islam from India during the 13th 16th centuries, the cult of the ancestors was revived and encouraged by Muslim rulers, with folk versions of denatured Hindu art adapted to it.
Colostrum, a high-protein form of milk, is produced by the second day after the birth and is gradually converted to normal breast milk, which has less protein and more fat, by the middle of the second week.
There are terrible low points, like "Limited Art Project," by the Chinese artist Yan Lei, a bit of endgame cynicism involving 360 fuzzily dead-in-the-water Photo Realist canvases that will be gradually converted to monochromes: Each day a few are spray-painted at a car factory near Kassel.
All contracts and prices were gradually converted to this new accounting unit, whose value in the old currency - the Cruzeiro Real - was readjusted daily.
Due to denitrification, 96% of added nitrate nitrogen (NO−3 N) was converted to nitrogen gas, with a mean flux of nitrous oxide (N2O) was 0.0268 0.1500 ug m−2 h−1, while 98.86% of thiosulfate was gradually converted to sulfate throughout the system.
At the initial one (less than 21 d), the amounts of HA were small; at the growth one (21 70 d), BG was gradually converted to HA; at the rapid growth one (70 91 d), the mineralization was accelerated and reached up to the maximum at 91 d; and at the late stage (over 91 d), the curve became steady at first and then declined after 105 d.
