This title appears in the Scientific Report :
2004
Please use the identifier:
http://dx.doi.org/10.1179/003258904225015536 in citations.
Study of production route for titanium parts combining very high porosity and complex shape
Study of production route for titanium parts combining very high porosity and complex shape
The synthetic vanadinites (Pb(x)Ca(10-x))(VO4)6F2delta, 1 < x < 9, adopt a P6(3)/m apatite structure with 9.7590 (1) < or = a < or = 10.1179 (1) A and 7.0434 (3) < or = c < or = 7.4021 (1) A. The partitioning of calcium and lead over the AI(4f) and AII(6h) positions is nonstoichiom...
Saved in:
Personal Name(s): | Laptev, A. |
---|---|
Bram, M. / Buchkremer, H. P. / Stöver, D. | |
Contributing Institute: |
Werkstoffsynthese und Herstellungsverfahren; IWV-1 |
Published in: | Powder metallurgy, 47 (2004) S. 85 - 92 |
Imprint: |
London [u.a.]
Maney Publishing
2004
|
Physical Description: |
85 - 92 |
PubMed ID: |
15017085 |
DOI: |
10.1179/003258904225015536 |
Document Type: |
Journal Article |
Research Program: |
Brennstoffzelle |
Series Title: |
Powder Metallurgy
47 |
Subject (ZB): | |
Publikationsportal JuSER |
The synthetic vanadinites (Pb(x)Ca(10-x))(VO4)6F2delta, 1 < x < 9, adopt a P6(3)/m apatite structure with 9.7590 (1) < or = a < or = 10.1179 (1) A and 7.0434 (3) < or = c < or = 7.4021 (1) A. The partitioning of calcium and lead over the AI(4f) and AII(6h) positions is nonstoichiometric with lead preferentially entering the larger AII site. High-resolution electron microscopy showed that samples annealed for 10 h at 1073 K are in disequilibrium with calcium- and lead-rich microdomains co-existing at unit-cell scales. For (Pb5Ca5)(VO4)6F2delta, sintering in excess of 2 weeks is required for the metals to order macroscopically. As annealing progresses, c/a, the partitioning coefficient kPb(AI/AII) and the AIO6 metaprism twist angle (phi) adjust cooperatively to enlarge the apatite channel, and thereby accommodate higher lead content. These results demonstrate that phi is a sensitive measure of disequilibrium and a useful device for monitoring changes in apatite topology as a function of composition. |