"Format" is not quite right, but you may be planning on doing the right things just under a different name. In general, there are TWO operations necessary to prepare a HDD for use. The first is to establish one or more Partitions. This just reserves certain areas of the HDD, each to be used as a completely separate logical drive. It is done by writing the space allocation details to a small table at the start of the disk, along with some other info in the MBR. You could make the entire disk one Partition, or you could make two or more smaller ones. Subsequent to doing this, each partition individually need to be Formatted. This installs on that Partition the File System used to track and control allocation of space from this Partition only to files. Very often the two steps appear combined into one, so people don't differentiate.
However, when your original HDD unit was made part of a RAID array, these two steps were done by the RAID management system. Some of the information placed in the Partition Table and MBR pertained specifically to the RAID structure and are no longer correct. For this reason I suggest you want to be sure that you do not merely re-do the second Format operation. You should Delete all the Partitions that exist on the HDD unit, then Create a new Primary Partition (full disk or less) and Format it (probably using the NTFS File System). If you do not plan to boot from this unit, the Partition you create need not be bootable. If you choose to make the first Partition less than full disk size, you can come back later and create a second Partition in the remaining Unallocated Space and format it, too. All of these tasks can be done in Windows' Disk Management, or by using third part utilities to help and simplify the steps.
I echo Saint19's small concern - what was the original problem? Was it simply data corruption that was resolved by rebuilding the array after the hardware replacement? Or, was there a hardware flaw involved that is unresolved? If you suspect hardware trouble, I strongly suggest you download for free from the WD website their Data Lifegard utility package. If possible, get the version that allows you to burn with it a bootable CD of tools. When you boot from that disk in your optical drive it installs a mini-DOS in RAM completely independent of Windows and allows you to run all its tests on your suspect drive. It can tell you what problems if any are present, and can fix a few. If there are unfixed problems, its info will help you to discuss with WD's Tech Support people what can be done.