Errata: Microdetermination of Dissolved Nitrogen and Oxygen in a Titanium Alloy by Secondary Ion Mass Spectrometry
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- ac D
+m
(ae
-
+ ac
,
[5a] [5b] Since Eqs. [5a] and [5b] a r e l i n e a r , the l i n e s r e p r e s e n t e d b y t h e m a r e s t r a i g h t l i n e s . In Fig. 1, the l i n e s M N and OP r e p r e s e n t Eqs. [5a] and [5b], r e s p e c t i v e l y . The p o s i t i o n s of the p o i n t s M and O a r e o b t a i n e d b y s u b s t i t u t i n g m s = 0 in Eqs. [5a] and [5b], r e s p e c t i v e l y . S i m i l a r l y , the p o s i t i o n s of the points N and P a r e o b t a i n e d b y s u b s t i t u t i n g m~ = 0. The v a l u e s a s s u m e d for F i g . 1 a r e : c A = 0.8, c B = 0.1, cac = 0.1, c~ = 0.1, r
--0.8, cy--0.1, -
=02,
0.04, a c B : 0.05, Ac C : - 0 . 0 1 ,
= 0 . 0 6 , ACE : - - 0 . 0 4 ,
ACA : 0 . 0 8 ,
AC; = - - 0 . 0 2 , ACy ACLB : - - 0 . 0 2 ,
ACLC
= -- 0.06. In the r e g i o n I of the t h r e e p h a s e t r i a n g l e IdK, A m a is n e g a t i v e and Aml3 is p o s i t i v e , in the r e g i o n
II both Am a and Am# a r e p o s i t i v e and in the r e g i o n HI ~ n a is p o s i t i v e and Aml3 is n e g a t i v e . T h e r e f o r e , the n a t u r e of the r e a c t i o n is e u t e c t i c for the a l l o y s in the r e g i o n II and p e r i t e c t i c for the a l l o y s in the r e g i o n s I and HI. R is p o s s i b l e that one o r both of the l i n e s r e p r e s e n t i n g Eqs. [5a] and [5b] will not i n t e r s e c t the t h r e e p h a s e t r i a n g l e . T h e r e f o r e , in m a n y c a s e s the n a t u r e of the r e a c t i o n f o r a l l the a l l o y s in the t h r e e - p h a s e t r i angle is e i t h e r p e r i t e c t i c o r e u t e c t i c . F o r an a l l o y of given c o m p o s i t i o n at a given t e m p e r a t u r e , the n a t u r e of the r e a c t i o n can b e a s c e r t a i n e d e i t h e r b y u s i n g Eq. [4] o r , b y finding out the a p p r o p r i a t e r e g i o n of the t h r e e - p h a s e t r i a n g i e for the c o m p o s i t i o n . The above w o r k was the r e s u l t of a h o m e w o r k a s s i g n m e n t in a t h e r m o d y n a m i c s c o u r s e given b y P r o f e s s o r L. L. Seigle, D e p a r t m e n t of M a t e r i a l s Science, State U n i v e r s i t y of New York at Stony Brook, Stony B r o o k , N. Y. 11794.
1. MatsHillert:Z Iron Steel Inst., 1958,vol. 189, p. 224. 2. J. Schrammand H. J. Luckert:Z. Phys. Chem., 1937, vol. 179,(A), p. 73. 3. MatsHiUert:J. Iron Steellnst., 1960,vol. 195, p. 203. 4. A. Prince:Z Iron SteelInst., 1960,vol. 195, p. 201.
C o r r e c t i o n to Met. T r a n s . , 1974, v o l . 5 M i c r o d e t e r m i n a t i o n o f D i s s o l v e d N i t r o g e n and Oxygen in a Titanium Alloy by Secondary Ion M a s s S p e c t r o m e t r y ,
by J o s e p h M. W a I s h , pp. 2104-07. P a g e 2105 F i g . 1 should have a p p e a r e d a s follows:
METALLURGICAL TRANSACTIONS A
VOLUME 6A, JANUARY 1975-249
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