1, ??????? ??? ???? ?? ???? ??????? ??? ???? ?? ?????? ??? ?????? ????? ?? ???? ??? ????? ????? ? ????? ??? ????? ??

2. ??? ??? ??????? ???

?? ????? ??????? 5A50 ???? ???? 265MPa ? ? 3A21 ???? ????: <167MPa;

? duralumin 2A11: 370MPa ???? ? ? 2A12: 390 ~ 420MPa ???? ? ? 2A13: 315 ~ 345MPa ???? ????;

3. ??????? ??? ??????? ????? ???? 80 ~ 100MPa;

4. ???? ?? ???? ???????? ????? ??? ????? ??? ???????? ???? ??? ????? ??? ??? ??? ??????? ?? ???? ???? ?? ??