Sad but I have to tell you that there is no hard drive in an iPhone since it is all configured with solid state memory. On an iPhone 5S and later devices, removing the solid-state storage will not help any longer. The data on it is encrypted and the decryption does not merely require your passcode. It requires that you enter that passcode on the original functional device. The decrypt key is tied to your passcode and the device hardware so without the storage chips in the same device (same logic board, CPU, etc) and all functioning properly, there is nothing to recover on that storage but encrypted gibberish.