H. Ying1)
,
X. D. Sun1)
,
Q. B. Yang1)
,
J. B. Li2)
,
Y. M. Wang2)
,
Z. Zhang3) and J. You3)1) School of Materials and Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China2) Departm ent of Materials
,
School of Mechanical Engineering
,
Shenyang University
,
Shenyang110044
,
China3) Liaoning Analyzing and Testing Research Center
,
Shenyang 110015
,
China
金属学报(英文版)
Starting from cheap inorganic salts , ultrafine P L Z T po w ders were synthesized by a co pre cipitation m ethod . The results show that the precursor precipitate obtained by the co precipita tion method transfor ms co m pletely to P L Z T phase by calcining at 420 ℃ for 4 hours , about300 ℃low er than the nor m al transform ation te m perature of P L Z T obtained by m ixed oxidemethod . The effect of residual N H4 N O3 in the precursor precipitate on transfor m ation te m perature of the P L Z Tpow der w as investigated . The residual N H4 N O3 in the precursor po w der can reduce further the P L Z Ttransfor m ation tem perature to about 300 ℃, but a sm alla mount of Zr O2 and Pb Ti O3 re m ained . By a proper control of the synthesizing route , a P L Z T po w der with a pri m ary particle size of 10 n m and an agglom eration size of 0 3 μm hasbeen produced .
关键词:
P L Z T
,
null
,
null
F. Zhang1)
,
X. D. Sun1)
,
J. You2)
,
Z. Zhang2)
,
L. X. Ding3)and Y. M. Wang3)1) School of Materials and Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China2) Liaoning Analyzing and Testing Research Center
,
Shenyang 110015
,
China3) Department of Materials
,
School of Mechanical Engineering
,
Shenyang University
,
Shenyang 110044
,
China
金属学报(英文版)
Synthesis of a m m oniu m alu min u m carbonate hydroxide ( A A C H) w as investigated usinga m m oniu m alu min u m sulfate and a m moniu m hydro carbonate as the starting m aterials . Itw as found that A A C Hcan be synthesized by adding a m m oniu m alu m inu m sulfate solution torapidly stirred a m moniu m hydro - carbonate solution at a tem perature of 30 ℃. A A C Hcantransfor m to α Al2 O3 co m pletely by calcining at 1100 ℃ for 1 hour , and the obtained po w ders , with a particle size of 100 n m , can be sintered to 98 99 % relative density at 1500 ℃for 2 hours .
关键词:
a m moniu m alu m inu m carbonate hydroxide
,
null
,
null
,
null
Y. Q. Jia1)
,
J. G. Li1)
,
Y. M. Wang2)
,
L. X. Ding2)
,
X. M . Qin1) and X. D. Sun1)1) School of Materials and Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China2) Department of Materials
,
School of Mechanical Engineering
,
Shenyang University
,
Shenyang 110044
,
China
金属学报(英文版)
Using yttriu m nitrate as the m other salt , synthesis of ultrafine yttria po w der through w et che mical route w as investigated . Choice of precipitant has dra m atic effects on co m position ,particle size distribution and particle m orphology of the precipitates . When a m m onia solutionw as used as the precipitant , the precursor precipitate w as m ainly Y2( O H) 5 14( N O3) 0 86· H2 O with co m paratively large particle size , broad size distribution and co m plex particleshapes . When sodiu m hydroxide solution w as used , roughly spherical α Y( O H)3·3 H2 Opre cipitate w ith sm all particle size and narro w size distribution w as obtained . The transfor m a tion sequence of dry α Y( O H)3 ·3 H2 O gel during calcination w as determ ined to be α Y( O H) 3·3 H2 O→ Y O O H→ Y2 O3 . After calcining at 600 ℃ for 1 hour , both Y2( O H) 5 14( N O3) 0 86· H2 O and α Y( O H) 3·3 H2 O transfor m to well crystallized Y2 O3 pow ders ,w ith particle sizes of 50 ～3000 n m and 20 n m , respectively .
关键词:
KEYW ORDS yttria
,
null
,
null
,
null
Q. C. Le and J. Z. Cui School of Materials & Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China
金属学报(英文版)
The 08 Al steel sheets were hot dip ped into Zn - Mn bath with 0 1 % Mn and 0 2 % Mn at600 ～420 ℃ bath tem perature , and then w ere treated in different w ays . The after - treat ments include cooling in the air at room tem perature directly , holding at the upper part of thehot dip galvanizing furnace for 60 s an d then holding at 510 ±10 ℃for 90 s . The results in dicated that blue , yellow , and purple , w hose coloration varied with the co m position an d thetem perature of bath and the w ays of after - treat ment . Finally , the mechanism of coloredzinc coating w as discussed .
关键词:
coloring hot dip galvanization
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null
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null
