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Wave-actuated Preform Infiltration Routines in MMC Production

Pennander, Lars-Olov LU (1997)
Abstract (Swedish)
Popular Abstract in Swedish

Avhandlingen omfattar tillverkning av metallmatris kompositer, MMC, baserade främst på aluminium legeringar. Nya metoder är utvecklade och undersökta där infiltrationen av fiberstrukturer av aluminiumoxid är stimulerad av mekaniska vågor vid frekvenser upp till 7 kHz. Vågrörelserna är genererade med nyutvecklad hög-magnetostriktiv aktuatorteknik. Målet med studierna har varit att åstadkomma homogena kompositmaterial vid relativt låga applicerade infiltrations tryck. En unik metod är utvecklad där infiltrationen sker i ett smältbad i ett resonant kärl och där den infiltrerade fiberstrukturen avlägsnas från smältan före stelning. Denna metod ger möjligheter att tillverka MMC med komplexa geometrier... (More)
Popular Abstract in Swedish

Avhandlingen omfattar tillverkning av metallmatris kompositer, MMC, baserade främst på aluminium legeringar. Nya metoder är utvecklade och undersökta där infiltrationen av fiberstrukturer av aluminiumoxid är stimulerad av mekaniska vågor vid frekvenser upp till 7 kHz. Vågrörelserna är genererade med nyutvecklad hög-magnetostriktiv aktuatorteknik. Målet med studierna har varit att åstadkomma homogena kompositmaterial vid relativt låga applicerade infiltrations tryck. En unik metod är utvecklad där infiltrationen sker i ett smältbad i ett resonant kärl och där den infiltrerade fiberstrukturen avlägsnas från smältan före stelning. Denna metod ger möjligheter att tillverka MMC med komplexa geometrier utan behov av dyra specialverktyg. De tillverkade MMC materialens hållfasthet och styvhet är analyserade. En fräskropp för höghastighets bearbetning är studerad som ett exempel på applikationer för de aktuella MMC materialen. (Less)
Abstract
The implementation of highly magnetostrictive wave-actuator techniques in preform infiltration processes for metal-matrix composite production is described.



Metal matrix materials require additional methods to handle the content, shape and position of the ceramic reinforcements, which are not required for metal alloy casting. Commercial fabrication of advanced metal matrix composite products has hitherto been marginal. One approach is the use of manageable substructures, preforms, of reinforcement elements bonded by a secondary ceramic phase, which can be infiltrated through their open porosity by the metal-matrix when molten. Infiltration of high density ceramic preforms is troublesome due to the dimensional fineness of... (More)
The implementation of highly magnetostrictive wave-actuator techniques in preform infiltration processes for metal-matrix composite production is described.



Metal matrix materials require additional methods to handle the content, shape and position of the ceramic reinforcements, which are not required for metal alloy casting. Commercial fabrication of advanced metal matrix composite products has hitherto been marginal. One approach is the use of manageable substructures, preforms, of reinforcement elements bonded by a secondary ceramic phase, which can be infiltrated through their open porosity by the metal-matrix when molten. Infiltration of high density ceramic preforms is troublesome due to the dimensional fineness of channel geometry and poor wetting conditions.



Present work examines the possibility of using highly magnetostrictive actuators to improve infiltration mainly of aluminium alloys into alumina short-fibre structures at low pressure differences. Models are derived to describe the coupling between infiltration and actuation properties. Experimental wave-actuated infiltration equipment have been designed, built and evaluated. The mechanical properties of MMC materials which have been manufactured are evaluated. An application of MMC-materials has been studied.



The theory and the models are formulated from established fundamental principles. The influence of preform fiber microgeometry on infiltration pressures has been studied using the concept of contact angles. Preform elasticity has been modeled for the determination of the properties of elastic wave propagation. Finite element analysis has been used as a tool to model the dynamic behaviour of wave-actuated crucibles containing matrix-melt.



A novel routine has been developed in this work, applying wave energy to a resonant crucible containing molten matrix alloy. An evacuated preform is immersed in the melt and the infiltration is then carried out at applied pressure differences of 2 MPa or less. The infiltrated preform is removed from the melt before cooling is started. This routine works without needing special tools for the MMC geometry, the MMC will attain the same geometry as the geometry of the initial preform structure. This method is found to have a higher industrial potential than the other researched concepts of this work. The best results of infiltration of high volume fraction preforms are achieved when the preform is actuated directly by a solid wave-guide. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Dr Savage, Steven, FOA, Stockholm
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Material technology, Magnetostrictive, Vibration, Actuation, Wave, Infiltration, Preform, Metal, Composites, MMC, Materiallära, materialteknik
pages
172 pages
publisher
Department of Production and Materials Engineering, LTH, Lund University,
defense location
Lecture Hall M:E at Maskinteknik Ole Römersväg 1, Lund
defense date
1998-01-16 10:15
external identifiers
  • Other:ISRN: LUTMDN/(TMMV-1033)/1-172/(1998)
ISBN
91-628-2722-7
language
English
LU publication?
yes
id
c3153c40-c822-4b31-ba93-8c3ca711c4fb (old id 18262)
date added to LUP
2007-05-24 10:49:12
date last changed
2016-09-19 08:45:07
@misc{c3153c40-c822-4b31-ba93-8c3ca711c4fb,
  abstract     = {The implementation of highly magnetostrictive wave-actuator techniques in preform infiltration processes for metal-matrix composite production is described.<br/><br>
<br/><br>
Metal matrix materials require additional methods to handle the content, shape and position of the ceramic reinforcements, which are not required for metal alloy casting. Commercial fabrication of advanced metal matrix composite products has hitherto been marginal. One approach is the use of manageable substructures, preforms, of reinforcement elements bonded by a secondary ceramic phase, which can be infiltrated through their open porosity by the metal-matrix when molten. Infiltration of high density ceramic preforms is troublesome due to the dimensional fineness of channel geometry and poor wetting conditions.<br/><br>
<br/><br>
Present work examines the possibility of using highly magnetostrictive actuators to improve infiltration mainly of aluminium alloys into alumina short-fibre structures at low pressure differences. Models are derived to describe the coupling between infiltration and actuation properties. Experimental wave-actuated infiltration equipment have been designed, built and evaluated. The mechanical properties of MMC materials which have been manufactured are evaluated. An application of MMC-materials has been studied.<br/><br>
<br/><br>
The theory and the models are formulated from established fundamental principles. The influence of preform fiber microgeometry on infiltration pressures has been studied using the concept of contact angles. Preform elasticity has been modeled for the determination of the properties of elastic wave propagation. Finite element analysis has been used as a tool to model the dynamic behaviour of wave-actuated crucibles containing matrix-melt.<br/><br>
<br/><br>
A novel routine has been developed in this work, applying wave energy to a resonant crucible containing molten matrix alloy. An evacuated preform is immersed in the melt and the infiltration is then carried out at applied pressure differences of 2 MPa or less. The infiltrated preform is removed from the melt before cooling is started. This routine works without needing special tools for the MMC geometry, the MMC will attain the same geometry as the geometry of the initial preform structure. This method is found to have a higher industrial potential than the other researched concepts of this work. The best results of infiltration of high volume fraction preforms are achieved when the preform is actuated directly by a solid wave-guide.},
  author       = {Pennander, Lars-Olov},
  isbn         = {91-628-2722-7},
  keyword      = {Material technology,Magnetostrictive,Vibration,Actuation,Wave,Infiltration,Preform,Metal,Composites,MMC,Materiallära,materialteknik},
  language     = {eng},
  pages        = {172},
  publisher    = {ARRAY(0xbbb46c8)},
  title        = {Wave-actuated Preform Infiltration Routines in MMC Production},
  year         = {1997},
}