MD-11 Captain reported an autopilot disconnect and loss of pitch control after aircraft intercepted ILS localizer. Crew responded with aggressive pitch over but still felt pitch control was heavy during flare and rollout.

Narrative

On turn to final and cleared for the approach; we were flaps 15 slowing from 210 to 180 and descending from 3400 to 3000 cleared for the approach. Autopilot was selected and approach/land was selected. Once the aircraft began to intercept localizer; the autopilot kicked off. I immediately selected the autopilot and the jet immediately began to climb. I deselected the autopilot on the yoke but felt I had no pitch control. I aggressively pushed over on the flight control to arrest the pitch with the assistance of the FO. After I felt I had control of the aircraft I continued to configure for the approach. At flaps 50 fully configured; I tested the pitch control by forward and aft movement. From 1000 to 500 I did several pitch changes to ascertain the feel. Jet was very heavy in the flare and rollout. Both FO and myself did flight control checks on taxi in and the jet was extremely heavy in forward and aft pitch control. During the entire event; there were no alerts or warnings accompanying the malfunction. Gave Maintenance a thorough debrief.Cause: Unknown at this moment. Suspect actuator jam or malfunction. No alerts were observed. Maintenance speculation only.Suggestions: Aircraft maintenance informed us that the jet had a history of like items. Possibly correct troubleshooting warranted.