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Analyzing Sintering Properties of Alumina Powder for Industrial
Applications
Peter Mueller
Lab Group WA2
February ! 2"#$
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Abstract
%&is e'periment was performed to determine t&e sintering properties of an
alumina powder! including green density! (red density! porosity! and linear
s&rin)age! and to use t&ese properties to recommend a design and procedure for
creating a beam out of alumina* "*$$ g samples of t&e alumina powder were
measured! pressed into cylindrical pellets by a 2""" lb load! and (red for +arious
durations at #"",-! wit& t&e p&ysical dimensions of t&e samples measured during
e+ery step* It was found t&at t&e procedure used ga+e a green density of 2*2$ .
"*"$ g/cm0! and t&at (red density and linear s&rin)age +aried wit& (ring time* It
was determined t&at sintering for "*0 &ours ga+e t&e best combination of &ig&
density and limiting of grain growt&* At t&is sintering time! t&e (red density was
e'trapolated to be ~0*10 . "*" g/cm0! porosity was found to be *2$3! and linear
s&rin)age was found to be #$*03* %&ese results were found to be e'tremely
reproducible! wit& green densities only +arying by 23 and (red densities +arying by
0 to 3! depending on t&e (ring time* %&ese sintering properties were in+estigated
to assist in designing a process for creating a cantile+er beam* %&e dimensions of
t&e beam are to be "* ' "* cm in cross4section and $*$ cm long and t&e beam
must be able to support a $" g load at $ cm wit& no more t&an 5m of deflection*
6ased on t&e linear s&rin)age +alues determined! a process for creating t&is beam
was designed! wit& a die pressing down perpendicular to t&e long a'is and mold
interior dimensions of "*7 cm ' "*7 cm ' 1*1 cm* %&e ne't step for t&e company
is to test t&is con(guration for green and (red density consistency as well as
accurate linear dimensions*
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%able of -ontents
Introduction
8'perimental Procedure 1
9esults and Analysis 1
:esign
9ecommendations ##
Appendi' A #2
Appendi' 6 #2
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conformation* %&is step is &indered by t&e friction of t&e walls of t&e die and by t&e
friction between granules* %&e second and most important step is t&e deformation
of t&e granules* %&e binder is c&osen to be mec&anically wea)er t&an t&e base
material being compressed! w&ic& means t&at under compression! t&e binder will
yield (rst* %&is allows t&e powder to initially >ow li)e a larger grained powder! butt&en allows it to be compacted into spaces on t&e order of t&e smallest particle*
%&e (nal step of compression is t&e actual ceramic particles being deformed
elastically and plastically* %&is step s&ould be dealt wit& wit& care! as lea+ing too
muc& elastic strain in t&e matri' w&ile compressed can cause t&e green sample to
e'pand greatly or e+en crac) w&en released from stress* %&ese crac)s are
signi(cant because t&ey could cause t&e green samples to brea) apart before being
able to be (red* Additionally! some of t&e crac)s could remain on t&e inside of t&e
sample t&roug& t&e (ring process! pro+iding locations for crac) formation andgrowt& in t&e (red ceramic! w&ic& would signi(cantly wea)en t&e (nal product*
Figure # s&ows t&e microstructural c&aracteristics of t&e t&ree stages of powder
compression*
Figure #* Micrograp& of alumina powder undergoing compression* ;a< loose state!;b< initial alignment stage! ;c< plastically deforming (nal stage ;-ompaction<
After compression into a greenB solid! t&e ceramic is ready to be sintered! or
(redB* %&e purpose of (ring t&e solid is to raise t&e material to a temperature
w&ere it does not li=uefy! but t&e t&ermal energy is &ig& enoug& for signi(cant
di?usion to occur! allowing t&e particles to rearrange t&emsel+es into a more
t&ermodynamically stable conformation! w&ic& almost always &as a &ig&er density
Mueller $
(a) (c)(b)
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t&an t&e green density* Initially! as t&e temperature rises! t&e binder burns o?! as it
is typically made of a polymeric material ;Gupta
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Figure 2* Microstructure of a ceramic sample during sintering* ;a< powder compact!;b< initial sintering! ;c< intermediate stage s&owing signi(cant di?usion! ;d< (nal
stage s&owing +oid reduction ;Francis 2<
%&e competing process to densi(cation is )nown as coarsening* -oarsening
is anot&er t&ermodynamically fa+orable process in w&ic& material from one or more
grains Dump across grain boundaries to add to larger! growing grains* %&is is an
energetically fa+orable process because t&e surface area to +olume ratio for s&apes
goes down as t&e s&ape gets bigger and surface area is typically an energetically
negati+e p&enomenon* %&is increase in grain size typically &as a negati+e e?ect on
t&e (nal properties of t&e material! as grain boundaries act as barriers for
dislocation motion! strengt&ening materials* %&us! a balance between time andtemperature s&ould be c&osen to ma'imize densi(cation w&ile limiting grain
growt&* Ene way to do t&is is to not sinter a sample any longer t&an it needs to
reac& t&e desired density! as once t&e density goal is reac&ed! any e'tra time will
only worsen mec&anical properties*
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After sintering! t&e sample is allowed to cool down to a safe temperature!
during w&ic& time s&rin)age typically occurs* Any material undergoing an increase
in density w&ile )eeping t&e same mass must necessarily decrease in +olume* %&is
decrease in +olume can be represented by t&ree linear s&rin)age +alues! one for
eac& dimension* Linear s&rin)age is calculated as ΔL/L0! w&ere ΔL is t&e c&ange inlengt& of t&e dimension and L0 is t&e original lengt& of t&at dimension* If t&e green
solid is created wit&out large density gradients! t&e linear s&rin)age s&ould be
largely isotropic* nowing t&e s&rin)age allows for t&e dimensions of a die to be
increased so as to lea+e a correctly4sized part after s&rin)age* %&e e=uation used
for t&is is!
9e=uired :imension H Desired Dimension /(1− ΔL
L0
). ;#<
As noted pre+iously! t&e strengt& of a sintered ceramic will +ary wit& its (red
density* %o design a ceramic part using sintering! t&is relations&ip must be )nown*
Ene e=uation found to model t&is relations&ip for sintered alumina is gi+en by
E H #"e40*1P! ;2<
w&ere E H elastic modulus of t&e alumina and P H +olume fraction of pore ;Francis
#
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wit& a piece of paper used to transport t&e powder ;MS
remo+ed from t&e die! weig&ed as before! and t&e diameter and t&ic)ness were
measured using a General model # &and calipers wit& a resolution of "*"# mm
;#&ours! respecti+ely! before being cooled to under #"",- o+er a period of 04$ &ours*
Finally! t&e sintered pellets were again weig&ed and t&eir diameter and t&ic)ness
measured* Additionally! t&ere was a sample of double mass! #*# g! produced using
t&e e'act same procedure and sintered for #*2 &ours*
General lab safety procedures were followed in t&e labC speci(cally! safety
glasses were worn at all times to pre+ent eye inDuries! and care was ta)en to a+oid
unnecessary in&alation of alumina powder fumes! w&ic& could potentially cause
minor respiratory irritation*
9esults and Analysis
An important topic of analysis for any production process is t&e
reproducibility of t&e results* In t&is process! t&e imprecise nature of doing t&e
measuring and die4(lling by &and means t&at t&is is t&e step of t&e process most
li)ely to su?er from reproducibility problems* %o e'amine t&e consistency of t&e
green pellet production process! t&e mass! t&ic)ness! diameter! and from t&ese t&e
green density! were measured or calculated* %&e student t4distribution multiplier of
2*#0#! corresponding to t&e #1 pellets measured was used to generate $3
con(dence inter+als for eac& c&aracteristic! and t&e results are gi+en in %able #*
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%able #* Green pellet $3 con(dence inter+als for mass! t&ic)ness! diameter! and
calculated density
-&aracteristi
c
Lower 6ound Mean @pper 6ound
Green Mass;g<
"*$"# 0.528 "*$$$
%&ic)ness
;mm<
#*$ 1.83 #*#
:iameter
;mm<
#2*1 12.76 #2*70
:ensity
;g/cm0<
;calculated<
2*2" 2.25 2*0"
%&ese calculations s&ow t&at t&e density of t&e green pellet will be accurate to
wit&in "*"$ g/cm0! or roug&ly 23! of t&e mean $3 of t&e time! w&ic& is an
e'cellent result gi+en t&e &andmadeB =uality of t&e process* Additionally! t&e
indi+idual measurements s&owed t&at for t&e #1 samples produced! t&e a+erage
de+iation from t&e mean was less t&an #3! s&owing a similarly tig&t distribution of
results* It was determined t&at random error dominates in t&is e'periment! as t&e
random error dwarfed systematic error! e+en wit& #1 samples being tested* %&e
sources of systematic error were t&e starting mass of t&e powder! t&e green mass!
and t&e pellet t&ic)ness* 6ot& of t&e mass measurements were accurate to wit&in
"*""# g and t&e &and calipers used to measure t&e t&ic)ness of t&e pellet was
accurate to wit&in "*"# mm* %o reduce t&e error on t&e t&ic)ness measurements!
t&e t&ic)ness of eac& pellet was measured 0 times and a+eraged to determine a
(nal +alue* As noted! t&e combined error from t&ese t&ree systematic error sources
was +astly lower t&an t&e random error present in t&e e'periment* %&e parameter
most responsible for t&e +ariations in measurement was t&e t&ic)ness of t&e pellet!
w&ic& was dependent on t&e o+erall mass placed in t&e die* %&is ma)es sense as
t&e diameter of t&e die is ('ed! causing any +ariations in total +olume to be
accounted for in t&e t&ic)ness of t&e pellet* %&ere was no discernable correlation
between starting mass and pellet t&ic)ness for t&e "*$$ g samples! li)ely due to t&e
e'tremely small di?erences in starting mass* E+erall! t&is is an issue for sizing t&e
indi+idual sample! but &ad no noticeable e?ect on density* %&is can most clearly be
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seen on t&e double weig&t sample! w&ic& was produced following t&e e'act same
speci(cations e'cept double t&e mass of powder* %&e pellet of t&is sample &ad
roug&ly double t&e t&ic)ness and double t&e mass of t&e normal pellets but &ad t&e
same density! being less t&an #3 less dense t&an t&e mean* %&is result is actually
closer to t&e mean t&an many of t&e normal pellets! s&owing t&at t&e o+erall massor t&ic)ness of t&e sample &as little e?ect on t&e density after compaction* It was
e'pected t&at t&e double mass sample would &a+e a density e=ual to or slig&tly less
t&an t&e ot&er samples! as t&e /: ratio increases! decreasing t&e e?ecti+e load on
t&e die as frictional losses increase* In t&is case! t&e /: ratio was still relati+ely
low! so t&e lac) of a di?erence in density is not surprising*
In general! green densities for ceramics are typically in t&e range of $$3 to
1$3 of t&eoretical density ;Sc&oenberg! Sun
&ard on t&e Mo&s &ardness scale ;Aluminium
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Firing time ;&ours< Lower bound Mean @pper bound" 0*2 3.30 0*01
"*# 0*0 3.55 0*1"*1 0*1 3.67 0*##*2 0*$$ 3.70 0*7
Additionally! Figure 0 s&ows density plotted against (ring time to s&ow t&e
diminis&ing returns of density as (ring time increases* It is clear t&at t&e density of
t&e (nis&ed ceramic rises as t&e sintering time goes up! but t&is process slows
considerably past roug&ly "*0 &ours*
4"*2 " "*2 "* "*1 "*7 # #*20
0*#
0*2
0*0
0*
0*$
0*1
0*
0*7
Fired :ensity +s* Sintering %ime
Firing time ;&ours<
Fired :ensity ;g/cm0<
Figure 0* Fired density +s sintering time* Four samples were created and sintered at
eac& sintering time
%&e mass lost by t&e pellets during t&e sintering process was "*"#$ . "*""#
grams! w&ic& is 2*73 of t&e original a+erage pellet mass of "*$27 g* %&e
t&ermogra+imetric analysis of t&e powder gi+en in t&e design memo s&owed a mass
loss of~
03! w&ic& matc&es =uite closely t&e mass loss as a percentage of t&eoriginal pellet mass ;Francis #
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range for t&e t&ic)ness measurement t&an t&e diameter measurement! as can be
seen in %able 0* %&is is a result of t&e diameter of t&e mold being ('ed! w&ile t&e
t&ic)ness was a function of t&e +olume of powder put into t&e mold* Any di?erence
in initial powder +olume was ta)en up as a t&ic)ness di?erence! leading to
signi(cant error range! w&ile t&e diameter was essentially unc&anging! leading toalmost no error at all*
%&ese diameter and t&ic)ness measurements ta)en in t&e lab allowed for t&e
linear s&rin)age to be determined* %&e +alues found are gi+en in percentages in
%able 0* As would be e'pected! t&e s&rin)age was greater for longer sintering
times! as t&ese longer times led to a larger o+erall s&rin)age and a &ig&er density*
An interesting note is &ow similar t&e t&ic)ness and diameter s&rin)ages are!
generally wit&in #3 of eac& ot&er! indicating t&at t&e material is essentially
isotropic* nowledge of t&e s&rin)age rates is )ey to designing a die for productionof a sintered ceramic part! as failing to account for s&rin)age will lead to an
undersized part and incur signi(cant retooling costs* It s&ould be noted t&at t&e
s&rin)age +alues are +ery +ariable and t&is must be ta)en into account w&en
designing a die to produce a speci(c part using t&ese met&ods*
%able 0* Linear s&rin)age of sintered alumina powder samples for di?erent sintering
times
:iameter s&rin)age ;3< %&ic)ness s&rin)age ;3
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%&e diameter and t&ic)ness s&rin)ages were also larger t&an t&e a+erages for "*#
&ours! indicating t&at t&e double mass pellet underwent signi(cantly more
densi(cation t&an t&e ot&er pellets* %&is disco+ery could potentially be useful in t&e
design of t&e cantile+er beam in t&at t&e beam creation setup could be designed to
be more li)e t&e double mass pellet t&an t&e ot&er pellets* Speci(cally! t&esintering could ta)e place wit& t&e beam oriented wit& t&e long side +ertical! to
allow gra+ity to cause more compaction! w&ic& seems li)e t&e most li)ely
e'planation for t&e greater density*
An S8M was used to image t&e surface of t&e sintered pellets to determine
surface properties! w&ic& are gi+en in %able * %o analyze t&e images! a small grid
was drawn on t&e surface on t&e same scale as t&e scale gi+en in t&e image! and
t&e a+erage +alue of eac& c&aracteristic found was determined* %&e properties
found were a+erage grain size! a+erage pore size! and a+erage pore content* %able * Surface c&aracteristics determined from analysis of S8M images
Firing time
;&<
A+erage Grain Size
;5m<
A+erage Pore Size
;5m<
A+erage Pore -ontent
;3<" "*2$ "*$# 2"*# "*02 "* 1#"*1 "*$0 "*2 00#*2 "*7# "*#2
Figure * S8M image of unsintered alumina sample! s&owing
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grid drawn on image to analyze surface properties
Figure s&ows an e'ample of t&e S8M images! wit& t&e grid drawn on to allow for
areal analysis* %&e a+erage grain size was determined by estimating t&e size of as
many grains as could be clearly identi(ed and a+eraging t&em* A+erage pore size
was done in t&e same manner! wit& pores generally being de(ned as t&e areas
between grains* Pore content was found by estimating t&e percentage of t&e top
plane made up of grains and subtracting from #""* All of t&ese +alues were +ery
roug& estimates! as t&e planes of t&e image are &ard to discern and t&e grains are
irregular in size and s&ape*
:esign
%&e memo for t&is e'periment calls for t&e design of a beam to support a
cantile+ered load wit&out e'cessi+e elastic deformation* %&e re=uired dimensions
for t&e beam are "* cm ' "* cm ' $*$ cm and t&e beam must be able to support a
load of $" g at $ cm wit& no more t&an m of +ertical de>ection ;Francis #ection in a beam is
νc= P L
3
3 E I z ! ;2<
w&ere νc is t&e +ertical de>ection! P is t&e load! L is t&e distance from t&e support to
w&ere t&e load is applied! E is t&e elastic modulus of t&e beam! and I z is t&e polarmoment of inertia of t&e beam* Sol+ing t&is e=uation for 8 gi+en νc H ' #"41 m! P
H "*"$ ! L H "*"$ m! and I z H widt&Nt&ic)ness0/#2 H 2*#00 ' #"4## m!
gi+es a minimum E of 20*$ GPa* %o e?ecti+ely use t&is +alue in an engineering
application! t&e elastic modulus of a porous! sintered alumina sample must be
)nown* An e=uation for determining t&e elastic modulus of a porous alumina
ceramic is gi+en!
E=410e−3.96 P ! ;0<
w&ere 8 is t&e elastic modulus in GPa and P is t&e +olume fraction of pores in t&e
sintered ceramic ;Spriggs
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would &a+e to be 71*23 alumina and t&us &a+e a density of "*712N g/cm0 H
0*1 g/cm0 to meet t&e re=uirements of t&is cantile+ered beam*
Figure #! s&owing t&e relations&ip between sintering time and density of
samples! was used to determine an optimal sintering time for t&e cantile+er beam*
As all of t&e samples sintered for "*# &ours &ad a density comfortably abo+e 0*1g/cm0! a "*# &our (ring time would be ade=uate to meet re=uirements* A longer
time ma)es more sense! t&oug&! as t&e modulus of t&e ceramic increases notably
beyond "*# &ours* %&e cur+e begins to >atten out as time increases and s&ows less
t&an a 23 increase in density after roug&ly "*0 &ours sintering time* %&us! going
past "*0 &ours in an industrial setting would simply be wasting time and money*
Additionally! gi+en t&at t&e &eat up and cool down cycles ta)e roug&ly &ours!
adding anot&er #2 minutes to t&e process is a minor increase in processing time*
Gi+en t&e 2"3 increase in elastic modulus and t&us safety factor t&is increasewould bring for a 03 increase in manufacturing time! a sintering time of at least "*0
&ours is t&e best c&oice* It s&ould be noted t&at "*0 &ours was not a tested
sintering time! so it is possible t&at sintering for "*0 &ours would not yield t&e
e'pected results* %&us! to con(dently proceed wit& a "*0 &our sintering time! it
would be wise to test t&is sintering time in a lab*
:esigning a die to use in t&e pressing of t&e alumina powder for t&is
application re=uires anot&er c&oice to be made* Ene option is a die "* cm ' "* cm
' $*$ cm wit& t&e pressing direction being parallel to t&e $*$ cm a'is* %&e ot&er is a
die "* cm ' "* cm ' $*$ cm wit& t&e pressing direction perpendicular to t&e $*$
cm a'is* %&e (rst option &as t&e ad+antage of being simpler! re=uiring a smaller
press &ead and less consideration of e+enly distributing t&e load! but would &a+e a
muc& &ig&er /: ratio! li)ely leading to lower green and (red densities* A &ig&er
/: ratio leads to lower green density because a greater die &eig&t contributes
more wall friction! w&ic& opposes t&e compressi+e force! reducing t&e e?ecti+e
compressi+e force* %&e second option would &a+e a muc& lower /: ratio and
would li)ely lead to &ig&er green and (red densities! but would be more complicated
to create and use! as (lling! pressing &ead size! and e+en load distribution would all
be potential issues* :espite t&ese potential problems! t&e recommended die s&ape
is t&e second option! wit& t&e pressing direction perpendicular to t&e $*$ cm a'is*
%&is is because all of t&e e'perimental data from t&is e'ercise was gat&ered using a
die wit& a similarly low /: ratio* Switc&ing to a die wit& a +alue /: O #" would
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really re=uire a new e'periment to be conducted to con(rm t&at ade=uate (red
densities could be ac&ie+ed and would in+alidate most of t&e wor) done up to t&is
point* @sing t&e die wit& t&e pressing direction perpendicular to t&e $*$ cm a'is
gi+es an e'tremely &ig& li)eli&ood of being able to produce solid alumina wit& t&e
re=uired density and t&us strengt& for t&is application* %&e (nal consideration for designing t&is beam is to ta)e into account t&e
s&rin)age of t&e beam during (ring* @sing "*0 &ours as t&e sintering time and
e'trapolating t&e linear s&rin)age +alues found e'perimentally! it seems reasonable
to use #$3 s&rin)age in all directions* %&e desired (nal dimensions must be
modi(ed to ta)e t&ese s&rin)ages into account! gi+ing!
Mold Dimension=¿ Design Dimension
1−Shrinkage * ;<
It is considerably easier to mac&ine o? a small amount of material t&an add
material to a sintered ceramic! so it was decided to round up on mold dimensions*
@sing 8=uation and t&e s&rin)ages determined for a "*0 &our sintering time! it is
found t&at t&e mold dimension s&ould be roug&ly #*2 times t&e design dimension
for eac& measurement* Multiplying t&e design dimensions of "* cm ' "* cm ' $*$
cm by a factor of #*2 gi+es (nal mold interior dimensions of "*7 cm ' "*7 cm ' 1*1
cm* %&e die! pressing down perpendicular to t&e 1*1 cm a'is s&ould &a+e
dimensions of roug&ly "* cm ' 1*$ cm! to allow t&e die to mo+e t&roug& t&e
mold wit&out binding*
%o replicate t&e conditions used during t&is e'periment! a sintering time of
"*0 &ours and a sintering temperature of #"",- s&ould be used! as noted in t&e
e'perimental procedure* Gi+en t&e mold dimensions and a desired green density of
2*2$ g/cm0 to replicate t&is e'periment! eac& mold s&ould be (lled wit& 0*2 g of
alumina powder* Also gi+en t&e die dimensions and t&e " MPa desired stress
applied to t&e powder! again to replicate t&is e'periment! t&e load t&at s&ould be
applied to t&e die is 22!#1 or !7$ pounds of force* @sing t&ese speci(cations
and t&e process outlined in t&e e'perimental procedure s&ould produce materially
consistent samples t&at meet t&e design needs of t&e Alumina -orporation of
Minnesota*
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9ecommendations
Ene issue t&at was noted during t&e e'ecution of t&is e'periment was t&at
simply using paper to load t&e powder into t&e die is not a +ery precise and clean
met&od* %&is leads to materials waste! inaccurate measurements! and most
importantly! die wear as spilled powder causes abrasion of t&e die* It would ma)e
sense to create or purc&ase a funnel4type tool to direct t&e powder directly to t&e
bottom of t&e die wit&out spilling or coating t&e inside walls of t&e die* %o best
replicate t&e successful results of t&is e'periment! it is recommended to use a die
wit& t&e pressing direction perpendicular to t&e long a'is of t&e beam! as t&is
reduces t&e /: ratio and &elps wit& pac)ing* As t&e current procedure gi+es a
green density of 2*2$ g/cm0! at or abo+e t&e typical range for alumina powders! t&e
current procedure or one similar to it s&ould be used in t&e creation of t&e beam*
As was noted in t&e design! t&e most logical sintering time to use would be "*0
&ours at t&e sintering temperature! as t&is time reduces t&e ris) of grain growt& and
coarsening w&ile gi+ing most of t&e possible density increase* %&is sintering time
s&ould (rst be tested in a lab to +erify t&at it yields t&e e'pected results before
mo+ing to production* Enly one sintering temperature was tested! #"",-! and it
ga+e a resulting solid wit& more t&an ade=uate propertiesC as suc&! t&is
temperature can be left unc&anged* %&is process gi+es a (nal solid wit& a density
of roug&ly 0*10 g/cm0 or "*$3 of t&e t&eoretical +alue for Al2E0 and an elastic
modulus of 27*0 GPa! w&ic& is well o+er t&e re=uired elastic modulus of 20*$ GPa
re=uired to build t&e beam* Finally! it must be noted t&at t&e beam will s&rin) upon
sintering as t&e material densi(es* %&is re=uires t&e die for t&e beam to be built
larger t&an t&e (nal beam to allow for t&is s&rin)age* %&e dimension increase factor
was determined to be #*2! gi+ing die dimensions of "*7 cm ' "*7 cm ' 1*1 cm* If
t&e user wants to truly eliminate t&e c&ance of a beam being undersized! a
dimension increase factor of #*2 or e+en &ig&er could be used* %&e data collected
in t&is e'periment s&ows t&at t&is process produces a material t&at meets t&e
product speci(cations and is consistent enoug& to Dustify mo+ing forward* %&e ne't
step s&ould be to create a die and mold in t&e speci(ed size and test t&e same
parameters ;green density! (red density< to pro+e consistency and create
speci(cations for scale4up to an industrial4scale process*
Mueller #7
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Wor)s -ited
6odiJo+K! atarinaC Pac&! Ladisla+C o+Kr! ladimirC QerRans)y! AloDz* ;2""1
Alumina -eramics Prepared by Pressure Filtration of Alumina Powder
:ispersed in 6oe&mite Sol* -zec& Silicate Society! &ttp//www*ceramics4
sili)aty*cz/2""1/pdf/2""1T"T20*pdf
-ompaction of -eramic Powders* ;2"#$
&ttp//en*wi)ipedia*org/wi)i/-ompactionTofTceramicTpowders
Francis! Lorraine* ;2"#$< Sintering Lab andout! :epartment of Materials Science
and 8ngineering! @ni+ersity of Minnesota4%win -ities
Francis! Lorraine* ;2"#$< -&apter $! Powder Processes! @nnamed Materials
Processing %e'tboo)
Gupta! SuroDitC Green! :a+idC Messing! Gary* ;2"#"
-eramic Green 6odies :uring Presintering* Uournal of t&e American -eramic
Society! 0 21##421#1* :oi #"*####/D*#$$#42#1*2"#"*"07"*'
Sc&oenberg! S* 8*! Green! :* U* and Messing! G* L* ;2""1
t&e %&ermomec&anical Properties of a -eramic :uring Sintering* Uournal of
t&e American -eramic Society! 7 27V2$2* doi #"*####/D*#$$#4
2#1*2""1*"#"*'
Scott! G* :*C ilgour! :* M*C ;#1
6ritis& Uournal of Applied P&ysics! Series 2! olume 2*
ftp//ftp*esc*cam*ac*u)/pub/gcs2/6ac)upT2TT"7/P&:/-S:/Scott32"
32"ilgour32"#1*pdf
Sintering* ;2"#$
&ttp//en*wi)ipedia*org/wi)i/SinteringXAd+antages*
Mueller #
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Sun! Yi4&ua! Ziong! Wei4&ao! and Li! -&en4&ui* ;2""
density [nE4Al2E0 ceramic composites by slip casting* %ransactions of
onferrous Metals Society of -&ina! 2";2"#"< 12410#
Aluminium E'ide* ;2"#$
&ttp//en*wi)ipedia*org/wi)i/AluminiumTo'ideXAbrasi+e
MS Precision 6alances*
&ttp//us*mt*com/us/en/&ome/products/LaboratoryTWeig&ingTSolutions/Precisi
onT6alances/MSTPrecisionT6alances*&tml# V :igital Precision -alipers
&ttp//www*generaltools*com/#44:igital4Fractional4-alipersTpT100*&tml
Mueller 2"
http://us.mt.com/us/en/home/products/Laboratory_Weighing_Solutions/Precision_Balances/MS_Precision_Balances.htmlhttp://us.mt.com/us/en/home/products/Laboratory_Weighing_Solutions/Precision_Balances/MS_Precision_Balances.htmlhttp://us.mt.com/us/en/home/products/Laboratory_Weighing_Solutions/Precision_Balances/MS_Precision_Balances.htmlhttp://us.mt.com/us/en/home/products/Laboratory_Weighing_Solutions/Precision_Balances/MS_Precision_Balances.html
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Appendi' A :iscussion of :ata Analysis Met&ods
%o determine t&e reproducibility of t&e results! a $3 con(dence inter+al for
eac& +alue was calculated* %&e met&od used to determine t&e standard de+iation
was t&e standard de+iation function ;stde+*s< in Microsoft 8'cel* %&is +alue was
multiplied by t&e student t4test +alue for #$ or 0 degrees of freedom! depending on&ow many measurements were ta)en ;#1 or
8/15/2019 Peter Mueller Sintering Lab Report
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Appendi' 6 8'perimental :ata
Thickness (mm< Diameter
(mm<
Mass (g< Green
Densit(g!cm3)
"e##et
$
1 2 3 4 5 me
an
"%&'
er
"e##e
t# #*7
##*7 #*7
0#*70
#*7
#*72 #2*# "*$$# "*$0# 2*2
2 #*71
#*7$
#*7
#*7
#*71
#*7$ #2* "*$$0 "*$00 2*21"
0 #*70
#*72
#*7
#*72
#*7
#*7 #2*$ "*$$ "*$2 2*20$
#*7
#*7
#*7
$
#*7
1
#*7
1
#*71 #2*1 "*$$2 "*$2 2*2$
$ #*7$
#*70
#*71
#*7#
#*72
#*70 #2* "*$ "*$2$ 2*21
1 #*72
#*7#
#*7#
#*7 #*7 #*7# #2*0 "*$$" "*$2# 2*21
#*70
#*7#
#*72
#*7
#*72
#*72 #2* "*$$" "*$21 2*212
7 #*71
#*70
#*7 #*7 #*71
#*70 #2* "*$$2 "*$2 2*201
:ouble
0*
0*17
0*1$
0* 0*0
0*" #2*7 #*" #*"12 2*20#
# #*7
#*7
1
#*7
0
#*7
2
#*7 #*70 #2*1 "*$$0 "*$2# 2*221
2 #*77
#*7
#*77
#*7
#*77
#*7 #2* "*$$1 "*$$" 2*27
0 #*7
#*71
#*71
#*77
#*7
#*7 #2*7 "*$$" "*$# 2*2$7
#*7$
#*72
#*7$
#*7
#*7
#*7$ #2* "*$$" "*$00 2*2
$ #*7 #*7 #*7 #*7 #*7 #*70 #2* "*$$# "*$0 2*271
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0 0 0 1 #*
#*70
#*7
#*71
#*7
#*7 #2* "*$$# "*$0" 2*2
#*7
#*70
#*7$
#*7
#*77
#*7 #2*72 "*$$# "*$0" 2*#7
7 #*$ #* #* #*# #*1 #*# #2*7 "*$ "*" 2*20A+erage
alue#*70 #2*$ "*$$# "*$27 2*2$2
Standard:e+iation
"*" "*"001 "*""2 "*"#0 "*"2$
@pper6ound
#*# #2*70# "*$$$ "*$$$ 2*0"$
Lower6ound
#*$ #2*177 "*$ "*$"# 2*#
%emp;,-<
%ime;&rs<
Fired %&ic)ness ;mm<
"e##et
$
# 2 0 $ mean
# #"" " #*10 #*$7 #*$ #*$ #*1# #*1"2 #"" " #*1# #*12 #*1 #*1# #*1# #*1#0 #"" " #*$ #*1 #*$7 #*$ #*$1 #*$7 #"" " #*$ #*1# #*1 #*1 #*$ #*1"
$ #"" "*# #*$2 #*$0 #*$2 #*$2 #*$$ #*$01 #"" "*# #*$0 #*$ #*$ #*$ #*$$ #*$ #"" "*# #*$ #*$1 #*$$ #*$ #*$ #*$$7 #"" "*# #*$0 #*$0 #*$ #*$ #*$ #*$
:ouble
#"" "*# 0*"$ 0*"1 0*"1 0*"1 0*" 0*"1
# #"" "*1 #*$# #*$2 #*$ #*$# #*$# #*$2
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2 #"" "*1 #*1# #*1$ #*$ #*1$ #*$ #*120 #"" "*1 #*$7 #*$7 #*$7 #*$ #*1 #*$7 #"" "*1 #*$1 #*$ #*$ #*$$ #*$1 #*$1$ #"" #*2 #*$1 #*$$ #*$$ #*$ #*$$ #*$$1 #"" #*2 #*$ #*$1 #*$2 #*$1 #*$0 #*$
#"" #*2 #*$ #*$1 #*$ #*$1 #*$1 #*$17 #"" #*2 #*1 #* #*$ #*1 #* #*$
Fired :iameter ;mm< Fired Mass;g<
Mass Loss;g<
density;g/cm0<
"e##et
$
# 2 0 $ mean
# ##*#"
##*#0
##*#2
##*##
##*#
##*#2
"*$#$ "*"#1 0*020
2 ##*#
##*#1
##*#$
##*#$
##*#1
##*#1
"*$# "*"#1 0*272
0 ##*#
##*#0
##*#$
##*#1
##*#
##*#$
"*$" "*"#$ 0*0"7
##*#0
##*#$
##*#$
##*#7
##*#1
##*#$
"*$# "*"#$ 0*22
$ #"*77
#"*77
#"*77
#"*7
#"*"
#"*77
"*$## "*"# 0*$1
1 #"*#
#"*0
#"*"
#"*"
#"*#
#"*#
"*$"1 "*"#$ 0*$#$
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#"*
#"*"
#"*7
#"*"
#"*0
#"*#
"*$## "*"#$ 0*$2#
7 #"*"
#"*7
#"*7
#"*"
#"*"
#"*"
"*$#" "*"# 0*$1#
:oubl
e
#"*
"
#"*
"
#"*1
#"*1
#"*1
$
#"*1
7
#*"0# "*"0# 0*1"
# #"*#
#"*2
#"*
#"*1
#"*
#"*
"*$"1 "*"#$ 0*1
2 #"*1
#"*"
#"*2
#"*2
#"*
#"*#
"*$0 "*"#1 0*11#
0 #"*"
#"*"
#"*#
#"*$
#"*
#"*0
"*$2$ "*"#1 0*1"
#"*"
#"*#
#"*#
#"*2
#"*2
#"*#
"*$# "*"#1 0*17
$ #"*1
#"*11
#"*1
#"*1
#"*#
#"*17
"*$2# "*"#1 0*$2
1 #"*1
$
#"*1
#"*
#
#"*
2
#"*
0
#"*
"
"*$#$ "*"#$ 0*#
#"*11
#"*1
#"*17
#"*$
#"*$
#"*"
"*$#$ "*"#$ 0*11#
7 #"*1
#"*1
#"*17
#"*17
#"*17
#"*1
"* "*"#1 0*1$1
A+eragealue
"*$#0 "*"#$ 0*$$$
Standard:e+iation
"*"#2 "*""# "*#1$
@pper 6ound "*$0 "*"# 0*"1Lower 6ound "*71 "*"# 0*2"
M ll 2$