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) Pb Sn (. .5). , , - . , 20% Sn, . - 250ºC .
327 |
10 20 30 40 50 60 70 80 90 100% Sn
100% 90 80 70 60 50 40 30 20 10 0
. 1. Pb - Sn
Pb - Sn (. 1) III , , ( ). . , . , . , , , .
:
ACB , ;
ADCEB , ;
Dm Sn Pb;
En Pb Sn;
DCE (T = 183ºC).
:
A Pb (T = 327ºC);
B Sn (T = 232ºC);
C 62% Sn + 38% Pb (T = 183ºC);
D Sn Pb (13% Sn 87% Pb T = 183ºC);
E Pb Sn (4% Pb 96% Sn T = 183ºC).
:
α Sn - Pb;
β Pb - Sn.
, Sn Pb , , Pb Sn ( Dm En ) . , , . , α - , , β - (β II) ; β - α - (α II). Dm En.
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(α II β II) :
1) -;
2) ( ), .
m α - Sn - Pb, n β - Pb - Sn.
m d , α - β II- , e n β - α II- .
:
(). , 62% Sn 38% Pb. 183ºC ; ; α- β - .
, d c α - , (α + β) β II- , . α - (α + β). α - ( ADC, ).
, c e, β - , ( + β) α II- , . β - (α + β). β - ( CEB, ).
, - , α β. (Pb Sn) t = 183ºC, . . , DCE. .
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( ACB) ( Pb Sn) .
III , .
, 80% Pb 20% Sn (. 2, 3).
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327 |
0 10 20 30 40 50 60 70 80 90 100% Sn 100% 90 80 70 60 50 40 30 20 10 0 t,
a 80%Pb+20%Sn
. 2. 80% Pb + 20% Sn
. 3. 80% Pb + 20% Sn
80% Pb + 20%Sn :
) , 80% Pb + 20%Sn, (. 1, 2);
) (. 2). , , ( ) ;
) - (. 2, 3).
. 3 80% Pb + 20%Sn - .
1 (T = 295ºC) ( ) (Pb Sn) . , 1, A C, .
1 α - Sn - Pb , a, ( ADCEB) . , α - AD A D. , , α - . ( 1 - 2). 1 - 2 + α - .
2 (T = 183ºC, DCE ) ( C = 0). (, , ), () , . T = 183ºC ( 2) :
1) , C (62% Sn + 38% Pb);
2) α - , , D (13% Sn + 87% Pb);
3) β - , , E (96% Sn + 4% Pb)
, DCE (T = 183ºC),
LC → α d + βE.
, D, C E, .
2 2′ (T = 183ºC) α - , (α + β) α - β - , (62%Sn + 38% Pb). , , . . 2 , 2 2′ , 2′ . 2 - 2′ α - , (α + β) . 2′ .
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2′ α - β II- . α - , m (2,5%Sn + 97,5% Pb), β II- n (99%Sn + 1% Pb). β II- α - : 1) - ( Pb), ; 2) - () , .
α - β - . (α + β), α β, .
- 250ºC , 20% Sn 80%
Pb, .
ADC 250ºC abf (. 1). , ( ), b.
Q. ( α - ) T = 250ºC :
Q me = ( bf / af ) 100% = 58,06%.
, Q. (), ACB, .
Q T = 250ºC :
Q = ( af/f) 100% = 41,94%.
Q (), ADCEB, .
α - T = 250ºC a 8% Sn + 92% Pb.
T = 250ºC f 38% Sn + 62% Pb.
T = 183ºC 2′ :
Q = (Dp/ DC) 100% = 14,3%
α - T = 183ºC :
Q.= (pC / DC) 100% = 85,7%
. 4. 80% Pb + 20% Sn
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) Fe- C (. .7). , - . , 1,2% C, - . .
(. 5) . , ( ), ( Fe3C). , :
1) Fe-Fe3C ();
2) Fe-C ().
:
(= 1539ºC) Fe;
(= 1493ºC; 0,5%) ;
J (= 1493ºC; 0,18%) ;
(= 1493ºC; 0,1%) ;
N (= 1392ºC) Fe α ↔ Fe γ;
(= 1147ºC; 4,3%) ( = + );
D (= 1600ºC; 6,67%) Fe3;
(= 1147ºC; 2,14%) γ - Fe;
G (= 911ºC) Fe γ ↔ Fe α;
S (= 727ºC; 0,80%) ( = + );
(= 727ºC; 0,02%) α - Feα;
(= 727ºC; 6,67%) ;
Q (= 20ºC; 0,006%) .