第２章 凝固に伴う組織形成 2.1. 現実の凝固組織 この章では ... - Tsuji Lab

. .Fe-19%Cr {001}. Fe-19%Cr 7

nucleusnucleationembryothermal fluctuation -L (2.1) Lhomogeneousnucleation. r classical nucleation theory. GL, G Tm T GL G GVG —GLdrivingforce43 " r 3 #G V!!4 " r 2 #8

"G = 4 3 # r 3 "G V + 4 # r 2 $(2.2) r .!free energy#g*4 ! r 2 "#gr*34 ! r #G / 3. r*!r " = # 2 $%G V (2.3)"g * = 16 # $ 33 "G V2 r*critical radius of nucleir*!r*r* r*(2.3)r*g*(2.4) GV Tm GV GV 9

! "G V= L ( T m# T)(2.5)T m L latent heat of solidification(2.5)(2.3), (2.4)%r * = " 2 # T ( %m1 (' * ' * (2.6)& $H f ) & T m" T)%"g* = 16 # $ 3 2T m( 1'2 *& 3 "H f ) ( T m+ T) (2.7)2! r*g* T .!. 10

2.2.3. heterogeneous nucleation.. " IL= " SI+ " SLcos# (2.8)!. 11

.Cu-Ni. Cu-Ni13

Cu-35wt%Ni.10.10 Cu-35wt%Ni ..10 X B0 Cu-35%Ni BNiB(Ni)-rich B NiBNiliquidus line B Nisolidus linediffusion.11.12segregation homogenization15

.11 Cu-35wt%Ni.12 A-B16

.13A-B A-B .13 T 6 eutectic reactionL (Xe) (X 1 ) + (X 2 ) (2.9) Xe pro-eutectichypo-eutectic .1417

.14 lamella structure.15Pb-SnPbSn.16.15 Pb-Sn18

.16 .17.18.19Cu-AgPb-SnAl-SiPb-SnAl-SiPb-Sn.20.21Al-Si.22.17 Cu-Ag19

.18 Pb-Sn.19 Al-Si20

.20 Pb-SnPb-40wt%Sn.21 Pb-SnPb-61.9wt%Sn21

.22 Al-Si22

.23 .23 A-B T 4 peritectic reactionL (d) +(b) (c) (2.10) .23 X 1 , X 2 , X 3 .24 Fe-C23

.24 24

Fe-C25