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Journal ArticleDOI

The wear of sintered aluminium powder (SAP) under conditions of vibrational contact

01 Nov 1964-Wear (Elsevier)-Vol. 7, Iss: 6, pp 535-550

AbstractEquipment to be used in the study of wear under conditions of vibrational contact, at temperatures up to 450°C has been designed. The following vibration patterns may be applied: 1. (i) torsional vibration in the plane of contact (fretting), 2. (ii) vibration normal to the plane of contact, 3. (iii) a combination of i and ii. The results concern the wear of sintered aluminium powder (SAP) against SAP in nitrogen gas and in liquid terphenyl. It was found that adhesion and metal transfer take place, irrespective of the nature of the vibration pattern applied. When either torsional or normal vibration was applied, volume loss was low. However, a combination of both vibrations led to a very pronounced increase in wear, which can be explained in terms formation and removal of wear debris. The influences of surrounding medium, temperature and normal loading were studied.

Topics: Fretting (59%), Torsional vibration (59%), Aluminium powder (53%)

Summary (2 min read)

Document status and date:

  • Published: 01/01/1964 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers).
  • Please check the document version of this publication: A submitted manuscript is the version of the article upon submission and before peer-review.
  • There can be important differences between the submitted version and the official published version of record.
  • The final author version and the galley proof are versions of the publication after peer review.
  • The final published version features the final layout of the paper including the volume, issue and page numbers.

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  • The results concern the wear of sintered aluminium powder (SAP) against SAP in nitrogen gas and in liquid terphenyl.
  • Die folgenden Vibrationsbedingungen konnen angelegt werden: (i) Torsionale Vibration in der Beriihnmgsflache (Bedingung unter welcher Passungsrost entstehen kann) , (ii) Vibration normal zur Beriihrungsflache, (iii) Kombination von i und ii.
  • In the unit in the foreground the pressure vessel has been removed; the specimen assembly A can be seen.
  • For the range of LIP values involved, the stroke S of the upper specimen decreases linearly with increasing A$, while both the maximum value of the load upon the specimens, L max, and that part of the cycle of vibration during which contact between the specimens takes place, to, increase linearly.

RLOCH3.

  • The results of experiments performed in nitrogen and in terphenyl under the conditions of vibration described in the preceding section (viz. those relevant to Fig. IO), are given first.
  • The influence of the surrounding mediwn and temfieratthe authors Owing to the fact that deformation took place under the normal load, the torsional vibration caused slip in the contact region.
  • The values of the total volume loss given in Table II were calculated from the diameters of the circular wear scars formed.
  • It was found that the amount of wear is dependent on whether nitrogen or terphenyl surrounds the specimens, the wear in terphenyl being somewhat greater than the wear in nitrogen.

EXPERIMENTS PERFORMED UNDER CONDITIONS OF COMBINED NORMAL AND TORSIONAL VIBRATION

  • Fig. 14. Contact region on the surface of a lower specimen worn against an originally spherical upper specimen in terphenyl under combined vibration conditions (A$ = 2 kg/cm*).
  • From Table IV it is seen that when only normal vibration is applied, volume loss is very low in comparison with the values observed under conditions of combined vibration.
  • Metal transfer still took place, resulting in roughening of the contact area (Fig. 16).

EXPERIMENTS PERFORMED IN TERPHENYL AT 135’C UNDER CONDITIONS OF TORSIONAL VIBRATION

  • Tables IV and V show that under normal as well as under torsional vibration conditions, volume loss increases exponentially with increasing Ofi.
  • The observed dramatic increase in wear when torsional and normal vibration are superimposed, is once more illustrated in Fig. 18, in which wear is expanded on a logarithmic scale.
  • Moreover, the removal of loose wear debris must be stimulated.
  • This is probably due to the fact that a liquid carries away wear debris more easily than a gas.

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The wear of sintered aluminium powder (SAP) under
conditions of vibrational contact
Citation for published version (APA):
Zaat, J. H., Commissaris, C. P. L., & Gee, de, J. H. (1964). The wear of sintered aluminium powder (SAP) under
conditions of vibrational contact.
Wear
,
7
, 535-550. https://doi.org/10.1016/0043-1648(64)90209-1
DOI:
10.1016/0043-1648(64)90209-1
Document status and date:
Published: 01/01/1964
Document Version:
Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers)
Please check the document version of this publication:
• A submitted manuscript is the version of the article upon submission and before peer-review. There can be
important differences between the submitted version and the official published version of record. People
interested in the research are advised to contact the author for the final version of the publication, or visit the
DOI to the publisher's website.
• The final author version and the galley proof are versions of the publication after peer review.
• The final published version features the final layout of the paper including the volume, issue and page
numbers.
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Download date: 10. Aug. 2022

WEAR
535
THE WEAR OF SINTERED ALUMINIUM POWDER (SAP) UNDER
CONDITIONS OF VIBRATIONAL CONTACT
A. W. J. DE GEE, C. P. L. COMMISSARIS AND J. H. ZAAT*
Metal Research Institute T.N.O., Delft (The Netherlands)
(Received January IO, 1964; accepted March 15,Ig64)
SUMMARY
Equipment to be used in the study of wear under conditions of vibrational contact, at temper-
atures up to 45o’C has been designed,
The following vibration patterns may be applied:
(i) torsional vibration in the plane of contact (fretting),
(ii) vibration normal to the plane of contact,
(iii) a combination of i and ii.
The results concern the wear of sintered aluminium powder (SAP) against SAP in nitrogen gas
and in liquid terphenyl.
It was found that adhesion and metal transfer take place, irrespective of the nature of the
vibration pattern applied. When either torsional or normal vibration was applied, volume loss
was low. However, a combination of both vibrations led to a very pronounced increase in wear,
which can be explained in terms formation and removal of wear debris. The influences of sur-
rounding medium, temperature and normal loading were studied.
Un appareil pour l’dtude de l’usure sous des conditions vibratoires et jusqu’tr des temperatures
de 450°C est construit. On peut choisir les conditions suivantes:
(i) Vibration torsionale dans le plan de contact,
(ii) Vibration normale au plan de contact,
(iii) Une combinaison de i et ii.
Les resultats concement l’usure de SAP (poudre d’aluminium cornprime, fritte et file) contre
SAP dans un milieu d’azote gaseux et de terphenyl liquide.
On a constate qu’il y a adhesion et transfert de metal sous toutes les conditions vibratoires.
Quand seulement la vibration torsionale ou la vibration normale est appliquee, peu d’usure
prend lieu. D’autrepart, une combinaison des vibrations cause une augmentation considerable de
l’usure. Afin d’interpreter ce phenomene, un m&an&me de formation et d’enlevement de debris
d’usure est propose. L’influence du milieu, de la temperature et de la force normale est Btudiee.
ZUSAMMENFASSUNG
Es wurde eine Apparatur zur Durchfiihmng von Verschleisspriifungen unter Vibrationsbe-
dingungen verschiedener Art bei Temperaturen bis auf 450°C entworfen.
Die folgenden Vibrationsbedingungen konnen angelegt werden:
(i) Torsionale Vibration in der Beriihnmgsflache (Bedingung unter welcher Passungsrost
entstehen kann) ,
(ii) Vibration normal zur Beriihrungsflache,
(iii) Kombination von i und ii.
Die Resultate betreffen den Verschleiss von Sinter-Aluminium-Pulver (SAP) gegen SAP im
Stickstoffgas und im fliissigen Terphenyl.
Es zeigt sich, dass Adhesion und Metalliibertragung unter allen Vibrationsbedingungen statt
+ Present address : Technical University, Eindhoven.
Wear, 7 (1964) 535-550

finden. Wenn nur torsionale oder nur normale Vibration vorliegt ist die Verschleissgcschwindig-
keit niedrig. Eine Kombination beider Vibrationsbedingungen verursacht aber tine ganz crhelv
lithe Zunahmc des Verschleisses. Zur ErklXrung dieser Tatsachc wird ein Mechanismus fiir die
Bildung und die Entfernung der Verschleisspartikel vorgeschlagen. Dcr Einfluss des Milieus, tlvr
Temperatur und der Belastung wird studiert.
INTRODUCTION
SAP (sintered aluminium powder) is a promising construction material in nuclear
reactor technology, because its neutron absorption is low, while it retains its strength
at elevated temperatures (for details see below). In order to obtain some indication
of the wear of SAP against SAP under complex conditions of vibration in nitrogen
and in terphenyl, it was found expedient to develop an apparatus in which it was
possible to put an upper specimen of any chosen shape in contact with a flat lower
specimen under the following conditions :
(a) The upper specimen should be capable of performing a torsional vibration of
previously determined frequency and (small) amplitude in the plane of contact, under
constant or, if desired, pulsating normal load. Figure r(a) gives a diagrammatic
I a bi
Fig. I. Diagram showing possible conditions of motion.
- time -
Fig. z. Characterization of normal vibration: (a) normal displacement of upper specimen as a
function of time (idealized curve) ; (b) normal load as a function of time (idealized curve). tc =
part of the cycle of vibration during which contact between the specimens occurs; T = oscillation
period.
Wear, 7 (‘964) 535-550

WEAR OF SINTERED ALUMINIUM POWDER
537
presentation of this condition of motion which leads to the known phenomenon of
frettingip2.
(b) The upper specimen should also be capable of performing a vibration normal
to the plane of contact, independent of the torsional vibration specified in (a). Figure
I(b) gives a diagrammatic view of this condition.
Taking the moment at which both specimens are still just in contact with each
other as the beginning of a cycle of vibration, this vibration can be represented by
Fig. 2.
For a part of the cycle of vibration, the upper specimen should be lifted to a
previously adjusted height and subsequently lowered again according to the curve
shown in Fig. 2(a). For the remaining part of the cycle both specimens should be in
touch with each other and a normal load should be built up according to the curve
shown in Fig. 2(b). If desired, it should be possible to apply both normal and torsional
motion in combination. By choosing appropriate frequencies, it should be ensured
that for consecutive cycles of normal vibration the upper specimen is always in
another phase of torsional vibration.
The environment of the specimens should be gas or liquid, the temperature being
adjustable from ambient to 450°C and the pressure up to IO atm.
In this article a concise description of the equipment is given with some actual
performance characteristics. Finallv, some experimental data concerning the wear of
SAP in nitrogen and terphenyl are given and discussed.
DESCRIPTION OF EQUIPMENT
A difficulty was to obtain displacement-time and force-time diagrams as shown in
Fig. 2. The principle of the system which was designed, is shown in Fig. 3.
Vessel A contains the specimens. Cylinder B, which is completely filled with oil,
is connected to an oil supply vessel C, via an orifice D. Vessels A and C are kept under
gas pressure, the pressure in C exceeding that in A. SinzLsoidal vibration of the driving
piston E causes the driven piston F to perform the forced normal vibration, shown
Fig. 3. Driving system for the normal vibration. (For description see text.)
Wear, 7 (r&4) 535~550

in Fig. z(a). During contact of the specimens, excess oil pressure is built up between
the pistons because of the continued downward motion of the driving piston. This
causes the normal load between the specimens to vary approximately as shown in
Fig. z(b), (The actual diagrams, recorded during performance, are shown and dis-
cussed below.)
A feature of the system is that the average distance between upper and lower
specimens remains constant, irrespective of the amount of specimen wear.
The general arrangement (Fig. 4) shows the implementation of the ideas outlined
above. The lower specimen I is mounted in a cage which is fitted to the upper part
of the machine by a screw connection. The upper specimen 2 is mounted on a vertical
shaft, which transmits the desired movements. The vertical vibration of this shaft
Fig. 4. General arrangement of equipment.
Wear, 7 (w64) 535-550

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Q1. What are the contributions mentioned in the paper "The wear of sintered aluminium powder (sap) under conditions of vibrational contact" ?

• A submitted manuscript is the version of the article upon submission and before peer-review. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher 's website. The final author version and the galley proof are versions of the publication after peer review. The final published version features the final layout of the paper including the volume, issue and page numbers.