[fso301]

The best suited materials for these high temperatures would have been made of nickle and chromium alloys depending on the application. But for the Jumo these materials were in extreme short supply.

Were the necessary strategic metals for the Jumos ever sourced in reasonable quantities during wartime, or was it a matter of by 1943/1944 the required metals were no longer available due to lost territory and closed sea lanes?

[henkster]

The chromium came from Turkey. I believe the Turks caved to Allied pressure and cut off supplies even before the Soviets drove into the Balkans. The German war machine was very short on chrome and Speer listed the exhaustion of chrome as the reason for his predicted inevitable cessation of war German production.

The nickel came from the mines at Petsamo above the Arctic Circle. Those were lost when Finland exited the war.