Giáo trình ma sát học - Chương 3 ppsx

25
.( :""1·,c." 'CH·UONG 3·
fW :. ~ '1 '1 .,. ,
NHUNO.VANDE.CQBANCUA LY
, , '" ,
'rWHUYET,MA.S:AT'11RONO·MA Y
;.1. NhU'ng d)nh lu,t cd bcin vi ma sat :
1.t>Oinh ,lu.t1 "
~t1~t' cua ma sat ngoai bc}ng t6ng cUa nh~t sinh
ra
vacac'nang 111~g-(fi1~'hAp th~ (chu y~u db kim ~Q
A=Q+AE .
':~1·biO;gl(f05l1g cUama sat ngoal:b~n 'hoan toan
thanh nh~t, n~n :
-Jiii rl:<+ a <'Aiva'i~"~~; ~
TY sa giua nang lu<;,ngbj hAp th~ va ~ng masat
ngoarfai rtf¢t d'~i 'lt~g thay c16i,ph~ thu¢c tinh chAt ~t
I~u va dl&u ~n ma sat ngoai': :~'
, ,.", A·E .,,, '.
- ~:Z= qJ(p,v,c)
A
<4 t)t'i')i' '.'j ;
! p: 'ap su't; v: V~n:,te6'trlt¢ ,:' , , .
;a:-wc·to cae thOng 56 ma sat, 'fAih chat cae v~t
I~u, mOl trudhg, nh~t d¢
1.2. O,nh:tu,t2 :
Lqcma sat 'fa 1&g caclqc thanh phc\n c1l1QCdUng
c1~tamMn ~n cae qua trinh Cd Jy hoa tAt 'yAtJ Ung va
c1"u k~n t~p
xlic nh't c1jnhcua cae v~t th~ ma sat :
25

26
T = T1
+ T2 + T3 + + T10.
T1 : Ma sat ~n trong cae Idp thuy khf dQng.
T2 :
Ma Sfit WiJ [tht:iY\<f~~ (c:aeIdp b~n) - sl! ban
Ioat ,,,,' . -
.1'"':
• ~.;, •. -!:/I .~ ~t.! :-~l ! "",:'i},<:" .,~.~ 't ~
'0 '. ,- I1P ;,.Tan .~t ;P,(n~JuQog ra;~!-(ph~~IQaO
dQngAm ra m6i trU'ang,phat ~ ).
Trong cae thanh phcin t~n T1,T2 xay
ra trong
chA dQ b6i trdll thuy d~ng; T3,T4,T5,T8,T9ti, T10 xay ra
trong qua trinh ~u&fi~;9iQh thU'qr,g;"T6.,.J7,~T8.r9kt:t,T10
,xcIly,ra, trong.qua trjn~ ma ~t~ng,·biflhJhtldng.
1.3. Dinh lu,t 3 :
Ung val mQt to h<;Jpcac th6ng ~('YClt'~/'m6i
trl100s)n~,4in~). cOl11Qtvung ;~tt:ic'dlJng Cd hQc,
trong dp;U~, oo4n e~p.tysO mlnglUc;JI19'dltqchap.thlJ
26
27
tr~n cOngella Ilfe ma sat ~y trong roan th~ tfeh bi b~n
d~ng cOglcitr! ct!e t~u':'~ ,
; f
f l1E~A.) = m in
A.
,i' ~~-: t>J BiflW'nh'f~'frin cho phep pht.h'tich qu~ trinhjna
satpli06 tilpwvaCfi"ra'm~n binh thLtang.Trong m~
ii~ti~ng Wta sat t5kinthanh ·rrl1~fca.'fci"d(f ta

16(oouMttl&unaMKh'm6f'cadf'h~u qua cae qua trinh'ma
," - 'J
sat ••••• ~t dltQC kha nang chOngmon, Unh chOng'rna
Qf\fIt ~ Wia lsat' mongmuOn. '
L l~' '<~
Qn51 otto &(1(.,,:.,1, " ",
')~l1rttu.da.f1f::;:'
•
_,~, Sq,~, o,tri \lUng cae qua'mnh IT1!l sat blnMtllflng vakhOng binh
!h~~"
,f " I: Vunp binhlhLkJIjIQ " 'd, b',i, :Jfl
."c., iJ CC', II: ViJrig c'huy~n t~'_ " , '
• \;2:i,~ III: Vung tKr h6ng'ca ~ ~n~ '-,n i:.
IV: ViJng tr6c
27
27
tr~n c6ng cua IlfC ma sat ~y trong roan th~ tfch bi b~n
d~ng cOgicitr! ct!c t~tf:·~
: f
J l1E~A.) = m in
A
T'
;i'~'-;6jBiflW!nhl~'f"tt!tl cho phep pht.htJChqut:itrinh_'ma
s:it,pfi06
tilpv~lvaCfi-ra'tn~nbinh thLtdng.Trong mi6n '
r:~u~n~ ~a sat fjkinthanh 'rth~t ca. "fC{dtf ta
!c\(~JfliuQaMKH'm~f'caCtr'h~u qua cacqua trin~ ma
sat •••• daJi (fltc;JC kha nang chOngman, tinh chong'lna
Qf\GII ~ Wiii tScit· mongmuOn
L 1<'"" '<~

~ntn Oft> Qf1C,: \, ".
'1¢11r1
•
28
28
2-1. Life ma acit :
~e trlJng
Cd ban cUa ma sat Ia tI!e ma sat, n6 Ia
Ille can tro chuy~n d!ch tlJong dOlgllta cae ~f th~ Mp
,,)(~C? ~h~,~ ,N~l '(~1tfl~ ~a nh~u":§"'~\flJ1lbtic phUe
~:)~'plro.r,lg,~9tA~~nl.eaCRuB trinh; C<1,h~ lMilkfYhf?e,
f:t <t'n.,~~,~~ qH~~ntl,~ha7":~~~'~a
br~hM~.ph;tt,th~~e ya() d~~,t1'l~ ~11~~1
Jd?tf~tJl:~U~.,~ " : nUb 1~ n*tn tSa
. Q TCt tau nglJa ta deltim;cach xay.P"", ••,., , ~
,,. tlRh.'loan Ille ma sat. Nam 1779 CulongeM "ng
1IIc_ Slit."" tOng cUa hal sllc can : sllc c8~ "'*- tfch ~p xue, sUecan ty ~ veri tal trQngNr .
~~'.''''''.':''.''"." f=A+P N ~. ". L
• " •• "Y ~ "II> +
. "de) .,.
'. ,,', A ~
H~ng 56 d~c ;rllng "Ohe.kha Mn
kAt glO'acae.ngu~n ta i
,-, 11_ HA50 ma sat . ,',,' j
'. t" •. ~,
N- Urc ~ap tuyAn/ j
"/ThlJdng A kha nhcrdo m~t t"p xtic Q6 dh6,
nan ; F = P N.
Cho dAn 'nay ce,ngthue trAn 'vAn'dll<:'Csa dlJng
trong nhctngtfnh toan g~n dung" M~t~ae, d!nh lli~t UlU

" , ' . f', ' ,:. ': : ~',f; ;l: \,- •
2 v! ma sat del cho bim c.'1c!Jtcua tup m~1sat theo quan
di6m nangJ~~~lr~ ~~ sU'd~ng cQtI1',dung bi6u thue
29
29
sau d~y d~ bi6u' ,diin.·quan ~c;1Jiqall!c ma sat va tai
~ '
'.: , i ~"',
~
t16i>f Uf'>' Cl1';"~ 1,i"F=.KN,t-rO
• r ••. .i r ,
h1 i;!~ :.K- th), S<}.ty:~ , iii teinghQP,ooa,bilng-s6-'dan;b~1
sl~,~ lita K1•cUe top.•bOktrdl1 td, ~n '.~ va ~ ht;.g
.ue6 <f~,d_·tuy6ntinh cua IOp~o del K2i,ngheita:pn1nn
~_~+~.' Qnuv Lil0,T
gOGO ",g; va P 18~ rthtlng s6;d~c trung cho t;t.a6ttiDa
u r ,
uR81ffg;~4afl,htli va diorvac·",t ~ ma~)i>, g,:Sorbt
n~jj 1-"03,:ThOhg d> phtln .ian. :0t1~,~;", "J~
aic phAn cOn _i. 'IT olp p1 Gig •••
• tiril1~rJhUCtr6Thdtif4Ung:!"'1 'l~l._
bibb thUang. Oi nhi6n , cOng chi: trG •• it.•••••••••••••
••••• •••• t
tSfnhlU~ cUa h!cma sat •••• ~~ .•
", ~ ~ ft' . ·1 bi oia • t~
2~2
tit .6ma sat : •••• onn
iv rBbC'GaR~rgJUa ~ sO'ma sat_ .'BI" lIMP
",Wnk11 ~ '~~:,';' .161 :)1;:) 8twt t60rt
aiD suo sortJ~~'-1 •. ; ;;.' ;; j~rl i"thi ;)('.) 6L.k.ttIM i~.t.'.Js,.L. '\ E>' ; ;" f?r!' i" 'i.t00. ~;.tt~f L {

•••••• nSlr!: . ' . 'rh V Yrii'-I\. '0 i i
30
30
, Quan ~ nay cO 3 vung,d~ctrll'ng: f i so use
Vung I : d~e trllng eho m¢t ehuy~n tkip '*'«10 .
ll'ng va cae tr! s6 p nhe; trong do khOng cO di~u ~n
i6binh thllClngh6a hoc;ur tb8nqua trfnh ma'sat. cae gicitI1
QfIi\J suAt ay khOn~rdu d~tam b6n va ~o dat tdl h~rt)lit
nhang ditU~n cAn chotinhth{ch
tlngcita ~t ~.
Trong wng chu~n OOpcae Ilfe cO 1k\tY quanJ"cifsl,l'dfch
6f.t(~8t eat;_n1 b&m~t ctenm~t khoang'+aich being
IchoIing
aidl giOa cae :ngu~n'tu-i &i dongval't~fGhu
ptJiiuttutllj ~~'ntnAl{o:;tnafsa.t. ·TY a6='QtE/A tI6n
•• gi8 tri ClIct~u. ,;-,' '060
••••• NII.'If" Ia;VfIrtgchungnhat;va~fflttqhg nhAt·
~ ••••••••••••••• '" " ••• ' .' " - ,- ' ~.', ,.h 4-,~'"~"'''''''lf.4i'lHU'dI1g. '.' .;,h;;.!;:; lHlN
, '11 J."tee_-jtrirmchu~ d6fva;" ~
, t ., me lit nhe nhcit. Ty 50: AE/A ~g d6i ••
L.l _• :11' ."" "nno ••• l 'i ~i be ;~? ~~ - ~
qSrtq ti.II.~gidUC;SC hap phyAE d\Hig.~ dBl vi
~t
hda CIic kip ~ m~t kim ~i. T~ng thai ~
cUs cae lcip h~t hoa d~t dll<:JCdo slf bao hOa cUs
Ollie
chAt hotIt tinh cOtrong vung ma sat va do trao d61nhltt.
Trong
wng"~phan 100GOngma sat ~llQCblAn •••••••
nhk\t : A ~(t- ,

. Vung IH-~n dqng 'liLpna_boqLcaecau true thlt
cap bao v~d~n ra m~nh hon, d¢: day cua lap ~o dal
VUc;1lqua tri 50 'tdi ~n, qua trinh ptittn ra cae cciu cUa
cae hc;Jpklm,(.~xuath~n . Quan h~ giua
h4 sO ma sat va
ap sucit phap tuy~n cOsai khae vdl qui lu~t tuy~n tinh.
'Tys6jl~ 'AEJA,ttlaya6ivahtra1gla~t gf&'Iii'ctic~i.
31
31
KA.tqua ~.c:U"''g
ta ch!~ d~ ma sat khOng binh
thUdngv2n~tf1hlthollg M m<ltt~ xtiexuAth~n, oo;th~
ohu~sangrtr601d~p;cito,xl!tdci
LLie nay AE/A=max
Ch~
d~ binh thU'dng dU'<;c me ttinh bllng h~ 86' rna' sat
6n <Sjnh va" hao rttOn chb phepr( hho: IihAt) dt!n ra do sL!
;hinb thimnicae cau :troe tml' ,dip' 5&11'~ If)4im~t cae kim
. ;~'·ch~,(tna'sat.:GICJlh~n cUa~ch6: ~Jam ~c binh
thttdng
dl:fqc'*'c dfntpb(,i ttj, s6aps~t phsp {uy'n ta
~n.pth' _. ;, ',i.c';' I" l.}c::1 ,,' 'i "F
V*,.wqtqLiaPtnl,ae~n,dtn'ft~nt~ trOe ~p'cao
XU'c!tG
:\9nbChig rqua trinh 1d10ng bftih thl((jng I<lute va
CUdlg)d~.khaG;nhau~:· \ ,).)
J,: ) i ;p, :: '~;
Quan h~ glO'ah~ 56 ma sat va tOe d~ trU'c;1ltftiHl4n'qua
hinh va : , = f(v)
.;._o~

~llIII II: , j6 III
V• ; 1.', - v
, - Ni v :th '
; CO:3 v~hg cfae trUng,;;tlldhg tl1 qua~ h.; gi£la , vaap
suat ph~~t~~~n'.' " ,
\{'~ng :11: cae qua trinh khOng binh:thU'~g ling va
had :m6h: phcn tr~n khi 'cOh~n tU<;Sng\roc ( 0< v < VttJ
.: ' . f:' ;. \- ,c' ••.
; VCtngU: ch~ dQ bfnh thU'CIlg li'ng vOl hao mon Oxy
h~ 61"1 dlnh (V'th ~ v ~ v"thl '
l Vung ,~II: cae qua tr.inh 'khOng binh thU'dng phat
trlin, khl:~ h~n 1u'9"gtroe nh~~
(V>Vth)
, . : , ' ~.
;~'I(j
32
32
Vung ~. ~~inb Unl'dJgdA;ctrttng bCl gia trj cSn
dinh cUa,h~~ ~ SjiitwiJtao,moo cho1phepdU'QC'quytit
. 4!l1h .QCl gia trt nhq nht\t ·cUa,ltIp b;6n: d~ng, cleo .va slf
hinh.~~nh '~qS44tt'\icthU'
aiP. ,"
OuEin;M gilla h~ .sOma ·sat V(ij"cac thOng 56
.~:y1dl/-Jlh«~~,~tl~u ~ ~g.ngh •. ch6~o chung,
.~chithll'dc ~~pJapghep, ~u va 'lihh.chcit cUa ch~t
bOitr~~ ~I"Q~g.·'Wng h~.Qja oacth6ng.,s6 6yiSirtam
thay deli ca~ ham s6 chu ytiu IJ = f(p) va IJ = t(V).Anh
_.c~~ JljJy ~u~ qtly6tdibh!M~ph9P,Qio,thOng 50
':l\v,~
~f~ng qu&t J.indt1~biitJ diin pang t~n tt't "

IJ = A{p;v;ef Ham nay chi cOy nghf8rkbLchAdt):n1a.&at
£.utJinh.·;Ul_Q1;" :f.<; (n
I
IJ = A { P; v; c} J
I I
j.l. =A{P; c } j.l. = A {~ c }
\ r:!:l -::~ni \/ :.l "",L
vOl v_ .,. '-"""I""p. -cosnt
.
I I !
I •. I " I
I I '.1 , L .1 .1 1 I , 1 L L
y . < w
•• "
• 1'0 ; "51 (). - .••.•'x" !,. X J t' e " f:1
\I ~ I"'C ., !~~i . ~ •.• "
~. \.I V ,v t" 0" '"" cr
"' .0, ~ : cQ ~. "-C .•~ ol •••••. · \00. ':0. e
I _. ~ .• 'r , ~ .•.•.I .;) \ ' •••••••; ~! \1) -<: =<.C ';",
~ •• '\) ~ .•• C" I'~. ,. ~ (~ ~ .'~
~. ~. V \~ ,c: ~ ~ •.~ .,t ~ ~ "t!.
I.g' ~
~cr p, -t.::, .••••. p ~ \.l.I
~ .~ ~~ ~ ~ g. g. t -+ 18- .'~ ~
~ (0 "'S ~ <ti "" -< l~ _ ,,~ ~
v· oJ' ~ 04 •• { .", <0 Ca.' ~ t:
~ ' ., ""~ :0 I \J Q:) ~ .~' ,' ••. ,~
~ ~i ~:1'-,~'" ~'r'~
\S 6
33

.3. CAed,ng ma sAt
3.1.
Ma sAt khOng eOehlt bOl tran :
Thl)'c t~ khOng cO nhOng be mat tuy~t d6i ~ch.
NhOng~ mat Iy tu6ng ~y chi cOthe ~ ra 6 cac phOng
thf nghi~m v~t Iy ti~u chulln. B~ mal chi t~t tuy khOng
bOi traQb6ng dllu mo nhung bao gio tr~n n6 cung cO
nhOng Idp mang Mp phl,Jgr,m hoi nuoc, khr L~i ma
sat nay xlly ra;Jtoac b<) phanh, truy~n dC)ngma sat
trong k~t ctiu may d~l , may thl)'c phllm, may hoe khi
~ig(Jfl9qllQC cac;ch8t~i
px:.p ,(sQ .h9~~n phllm
h* vi
a~ ki~n an loan) hay trong~nhOng.may m6G
lam vi~
a nhi~t dC)cao khi ma b«t IcY chat bOitrdn nao
GOng
!<hOng thfch hQP. Ma sat khOng cO c~t bOi tron
thuong kern theo Sl)'truQt kieu buoc nhay cUa ~ m$t.
GSn lien voi hi~n tuQng nay la Sl)'rung 'cua 010khi vao
khop, t~ng r~~a_ phanh, SI)'gi~t khi phanh, SI)'rung
dOngcUs dao ~ khi cat. f)e ch6ng IGlixung Il)'ckhi ma
sat phai tang dC)cung VOngciJa~ chQn<;$pma sat cO
h~ sO ma sat fi¥1g
rt khi thai gian t~p xuc trnh dai va
khOngcOCl)'Cttl!u.
Mang oxyt, dC)Ilm va bl,JibIln tr~n ~ mat kim I~i
anh huang rO r(!t ~n h(! sO ma sat . MOt m(U Il)'c hut
phin:tUgitl,u~hungoo theflhoh~:hang tram Illn so voi
,,". "",.,

trtIOng hWtuong tOO10m~ ~ch ;H~ spm~ .tpb•••
thu()c truoc ~t vao v~t li(!u ~ m~.Ji8p xUp[~"ng th$i
lop ~ IJljt QQrlgnhu v89tai tr9n9 va v$ntOc _
JfQng.cae tai 1i~,thao1.knao·~~"~· nghien cLiu
v~ vai trOcua lop be mal CI,Jthe I~ dOCuOgva .c4u 1:f'!jc
hlnhhC)Q-nh41dQbOng,-huong gia cOngo
34
34
•. );
,[ . ro.
'l
.• ~ I'
,
, - BantllukhiQtArig~n; fJ.'giAmxu6ng'~n;gia·ttj
nhtft.din,~clJa'~,.sau'd6 ~ t1;Jc tari~:Q'WJi~ iff ktll\\
fan ttllfJ.tahgf&n r6-r~_ <,,'
Theo 'nghiOO coo 'ctia Nieman va,Gartner wang
hQpcap vat Ii~ula thep tOi,khOngbOitron, ~ mat dUQC
colla~h
J,L:~;Okt1i'~n-t6C truQt·~tnoovafJ.:::O, 11 khi
van
t6C'tfuQt I~n_.
Hai Ong dua rad>ng thOt sau"~ tfnh .~ s6 me
sat khO:
35
1 + (rnVJ
?'
. J.:lso + ~(mVs)
Jls= .,~
Trong <l6:

"or - ":" •. ,'" '_ ",
Ilso: H~ S6ma'satkho khi Van t6c Vs = 0
J.ta.o : H~ s6: ma sat, kh~ khi van t6c Vs ~ «)
\is :: van t6c truQt,.: ;'" .
m: H~ s6 phJltJ;luOC'vatJj~ va,~ng thfa ~
m~t.' . ,
(Ilso = o,32 b,f6:~CX)'= 0,04 0,02; m=O,02 0,04)
H~ s6 me ~tih6'rit'khongbn "dinh, vf d-•••, glo8
thep va ~p hay ~J'~i 4~9;,J;;9ngj(iathep voi ~c
,'ot;li:~at-J'~:'~~,_~the lam, yi~;~<3';1p;r.n~tttlOigj~n ~t
dlnh;k!lf ~v~ 16ct
tr~c;it bBng Ctlfnh. v$r\ t6cQal (\I,t;n(),
V2~ar!'~,','::IlE ',; . :.' ,J :. ,_ '
1'1 -, ,', ' ~ ,
7.••. i!."i •. ~ jr •~e _:.: ,
_,5 TW.;' ". - ' L.'·' ,__ •• , "
,'" ,:. t:. ~, ••.4l: ••••••••• ~
, ,~j ,+
'., c Cdt(giOaVu,~p\/O,'thep,~hoacgt~'thep voi dbng
~. ;m~(cl.!itit1tbi pri~ h~¥~han~ :9~6~t IdJ,Ongthe titlp
tl,lClam ~'dU(tC,I(~ m~tt>i troc, :rung mt;lnh, keu to,
khong·~~t1~ctl)Vi~(frau d4Qt (ghi v~ppilt ~\L ktjL llim.
vi~). Thfngtll.rOng hQp 'me safkhO nhu yay, Il,Ic ma sat
36
each n6.
Trong d6:
a : Cuong de)trung blnh c~ th$nh ph~n
, ph~n tv cUitl\lc .mas4t,
/,S~: Di~n
tr,C~'~>~~',tt)\Jc,~. ,

b : H~
56d~ trun~,Fho th,anh'ph~n co
," hQCcua IV~
111ft ~( .
N-':Apt'l,IcphAp tuY'n.
Nhuv&,y:
fl. = (a.SJ{N t b
3~2.Ma sM khic~~iJrO'".g!6:i,tI.n;c
~ i~~ :. -,' . -':""~L" ~;~_" ~" <\ ;~' ,·~~::-:":f "Vt i"'; _:, ,,,,:
,,' K!1l. ~i,!':On~i~f-~~Il, cab' :~" trjl~I+p.g~~p" ~
pflAn cAelfbOi'mOflap ctlftbOi tr9h rat "l6ng. Nhung do
c6 lop
n"IY 11)& ma sdf gi'rtt W 2 ~n 10 Iln va giatn dQ
mOO~~t lap ghep hang trAm Iln so vai truong hQp
ma sAt khOngc6 chilt bOitron. "
f>e)ben cUa mWlg~.l'.l phl,l ~uQc vao Sl) c6
m$t cUacAc phAn tti ~~nQ, cb4UuQng va 56 IUQng
cUa chung. M$C dlu c6Ct~idlut<hotmg la h<:mhQp
cUa cAc ~i CacbU(:~Hy~.ro,~ h~t dOng, nhung
bao gio cOngc6
14n mOl ft~,f).iJuoo~ keo, mOt56 ch«t
,,~ ~;.j rt ":-iu~•.,,,,<, 1., ' ,_.' ,
, h~t trnh be m$t khAc. cae ch«t be<>c6 trong thanh
phln cua dlu tI'll)C,vat va d()n~.vlt cOng nhu trong
thanh phAn cua ~ bOi'fron deo.
Vl vay gln nhu ttit ca
cAcdlu bOitrQn ~u ~o.thanb ~nJ~ m$t kim Io~i pha
~9,i.h~Hc6 Mu If!.fctinh.,~ gia, chi~,u~~n,Oi1m~.
U~p nl~ C6m~l~nJ(tn ~n hO$<;khOng.,~n Yoi ~Jn$t-
~~u lop ~~u giOa"cAc'~ m$tm~ sattuarl$l.~iday thl

sOc'chuyen'tO,afu trUc ~nh buang qeja"dlu sang c4u
~- ~- - - , ' ~
37
· ~ ~
So d~ tru¢ cUBv$t rAnkhi bOitron giai h~n
~ BOitron b~ m~ Iy tuong
~ Tifp XUCCUBb~ m~t thl,rc
A : Do~n truy~n tai trc;mg
8 :Do~n tifp xuc thl,rc
38
38
Nho
,c6, ~~, Unn,4011geua, cac phan tv c~t bOi
frori sd
'flip tht,lxay ra\lai t6c de) 'an tr~n ~ mat me ~t,
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.".rc"I6p gJuQ9.i la I,?ptai. Khi chi~u day lop d~u,ron,han
ch~u day mang giai ht;mthl anh huang cUa be m~t toi
42

42
cac philn ill dilu
a xa sa giam di. Cac lap cach ~ m~t
o
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n~y voi h~ s6 ma sat nh618 t6i uu d6i voi k~t a1u ma sat
v, phuong dittn ~t m~i nAng luc;:mg,d~ ~n mon va
tuOithQ.Trong bOit~9n
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ban chatwa ~ m~f~p:ghep. ',' ,
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tu coo
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43
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long. D~ ~ b6i tran
ma sat uOt :.h >'~i +Ra.
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thanh
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p~ 1,33+1,65.(. 4~i~+'i;2~:t:
44
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11' : f)O nhot eus dlu tran ~ miIlt.
~=~1+~2 I,
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Ii~u th~p va bOitr¢'bangdiiW khO$ng.
k2
= 0,02 . " !,
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tron thuy dOng gioi th~u :
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q : Tai trQng don vi
V1,V2 : H$ s6PCil8txong."


45

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.••• Tinheh6ng.masatvi. tinhrnasattua cae chi
tiit may •
V~c bao dam hai
tinh do Ia rn¢t trong nhang
nh~m
v~ quan trQng nh~t trdng S6 nhang ~n dEichung
vt me salMi tran va marrnan.T~ng thai tthh ch6ng ma
sat d~ ~c trttngi'bCti 'h~ s6 rna sat nhe ~ 6n dinh va
d¢ ChOngman cao va kha nang chen'
rii tot: Cot1~ng
thai tinhrna satd~ d~c tnmg b6'i h~ 56 ma sat Ond!nh
-va t6i uU)~ d~ ch6ng I'1'lOnhAm trong -phqm vi echo
phep.
.4.:1. Tin If GhAng rna sat :
')I(eh~p~t",c V~'r1g6ng·~c.; ,-
cac nhan to anh huang' tdj' ~~g' 'tha;ttrnh~&6ng
ma.sat:.
,A· . 'I
; , • tJ<h8(nlj ng ch~yra' t6t.
- Tinh khOngdOng nh~t cUa diu tn.ich<.;JP'kim,~'thf
d~$l!t6n~bre'hf1t rantrong n~nde6.
• 'Thanhph'fi1h6ahQc va cau'trUc h<;fpkh1l.
'.;Hinh hQc cua'~u 'true b3 "'~t;'b~nd~ng t6vL
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trong vung ~p masci!.'

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tinh chAt Cd hQc
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bai
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sat c6 bOliran gia hqn tinh ch~t cUa v~t I~u 0 tr~c bao
46
46
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nheil, nghia
iii chung chi bf'ph~ h~i vqjap.$ulIt va nh~t
dQ.CVc d~i " . ' '.
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,nqon,grfihOICip mlY bj pha
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cUng ccip dciu bOitrdl1 g1811cloqn. OOc-knac:phl:/cdung
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~~ g~mva kb~ng ~otfnhLt,.ong m¢tthq,,gtan.,dai cOth~
Khi lap bOitrdn tdi h~n bj pha h~j,PlW~.
Dl!a tr~n nhctngdi1lctrLtngdO,eh~
~Q ra cae ~i
v~t I~u lam e; trl:/c nhLt':
, ,'t,.hl,Qp kimchOng ma"scjt { ~,bit '" chi, babit _
thi&e). H9P kim nhOm kem, h9P kim dOng-chi, h9P kirn
~Ong- ttl~.n-mangan, 46ng thanh- ~hkic- chi
47
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+
cae v~t I~u cO 10x6p ~ vi: dung b¢t klm lo~i ep
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I~u ~o ra
trim Cd sO cc:i6 philn ttt nhu nhl!a ~onol
Forma,1ho~c nhl!a poliamit.
.t2. Tinh ma_t:Phahh:'
',>,: "Y.u diu ca:c'.~W~~~t dung ttorig ph~nh'~ '

, . ':;'~ ,Ifnh' ~~ng
mon .qaQ~ ~h,~nang lam v~6' v~ ap
suatri6ng icao ~aphc\n phj 'kim ~i. '
'l' 80mjt ~Dg 4ltc;IC trPcQjnh.
, , ; ~aac ~ti I~u me sat khOng ,bt ohay sinh Jdloi.
o ,",' ll'tY$o~:aic'b8c hqc'Ng&: "j 1
.~,"'6'$6 ma saif'p' ha1 caltri s6 t!u'lm 02 < .i < 0 5
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va phai On djnh trong' quait¥inhph~nh khOng>du~thay
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nhu ddng phanh '
"' •• r .•
- Q8f(J¢'bAn·chOng han·rreao.
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U'ngvOl nh~t dQ, th~ tich cl!c d~
i~ora trbrtg phanh.
- Hao mon cUa ~ melt khOng vu¢ qua g~ tri. cho
:' ,,; •
"
' .;'
trude " ,
.• -co dQ dan nhklt",nh~t dung Idn CO tinh GOng
I •
ng~du.cao khich6tc,o.
48