- TITLE:
EXPERIMENTAL STUDY OF FRICTION COEFFICIENT IN DIAMOND BURNISHING OF CuAl8Fe3 BRONZE
- AUTHOR(S):
A.P.Anchev, D. K. Drumeva
- ABSTRACT:
The article presents the results from an experimental study to determine the friction coefficient in
diamond burnishing process of specimens made of CuAl8Fe3 bronze alloy. The experimental study
was performed on a lathe C11 using a specially developed device containing a strain gauge beam.
The studied burnishing process was implemented through a deforming tool with a spherical tip made
of polycrystalline artificial diamond. The experimental study was performed in the range of sliding
velocity minm17243v . A regression analysis was performed and a mathematical model of
the friction coefficient depending on the sliding velocity was obtained.
- PAGES:
34-
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EXPERIMENTAL STUDY OF FRICTION COEFFICIENT IN DIAMOND BURNISHING OF CuAl8Fe3 BRONZE
- TITLE:
EFFECT OF DIAMOND BURNISHING PROCESS ON THE TREATED SURFACE TOPOGRAPHY OF SPECIMENS MADE OF CuAl8Fe3 ALUMINIUM BRONZE
- AUTHOR(S):
A.P.Anchev
- ABSTRACT:
CuAl8Fe3 aluminum bronze possesses good strength, wear resistance and corrosion resistance,
including in salt water. The presence of iron leads to grain refinement, which gives extra strength to
this alloy. Thus, this bronze is the preferred construction material for various applications, including
marine. As this bronze is not subjected to heat treatment due to the lower aluminum content, surface
integrity (SI) is improved by cold work. The article deals with diamond burnishing (DB) of CuAl8Fe3
bronze. The object of study is the surface topography (ST). Usually not all ST parameters are used in
practice. The parameter is one of the most used in the production process and in the process of
quality control due to its easy measurement. However, this parameter is not sufficient to describe the
features of the surface texture, on which the performance properties of the respective component
largely depend. The article examines the effect of DB on eight ST parameters - six height and two
shape parameters. Based on the obtained results, the behavior of the respective component is
predicted from the point of view of wear resistanceaR
- PAGES:
29-
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EFFECT OF DIAMOND BURNISHING PROCESS ON THE TREATED SURFACE TOPOGRAPHY OF SPECIMENS MADE OF CuAl8Fe3 ALUMINIUM BRONZE
- TITLE:
ENHANCEMENT OF FATIGUE STRENGTH OF CuAl9Fe4 BRONZE VIA DIAMOND BURNISHING
- AUTHOR(S):
A.P. Anchev
- ABSTRACT:
Aluminum bronzes are non-ferrous alloys characterized by good strength, wear resistance and
corrosion resistance, because of which these bronzes are preferred construction materials for
various applications. When the aluminum content is over 9%, heat treatment can be performed in
order to improve the mechanical properties - tensile strength, fatigue strength. Further increase of
fatigue strength can be realized by means of surface plastic deformation. One method of this is
diamond burnishing. The article shows the effect of using diamond burnishing on the fatigue
behavior of samples made of CuAl9Fe4 bronze. DB with one pass increases the limited fatigue
strength by 11.9% - from 420 to 470MPa. At the same time, the fatigue life increases more than 40
times. Increasing the number of passes from one to six increases the effect of DB in terms of fatigue
behavior - the limited fatigue strength increases from 420 to 490 MPa, i.e., by 16.7%, and the fatigue
life increased more than 77 times. Based on the results from the fatigue tests, it was concluded that
DB is an effective, reliable and economical method for increasing the fatigue strength and,
respectively, the fatigue life of CuAl9Fe4 aluminum bronze components.
- PAGES:
24-
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ENHANCEMENT OF FATIGUE STRENGTH OF CuAl9Fe4 BRONZE VIA DIAMOND BURNISHING
- TITLE:
FINITE ELEMENT ANALYSIS OF THE DIAMOND BURNISHING PROCESS OF HOLES IN CuAl8Fe3 ALUMINUM BRONZE
- AUTHOR(S):
V. P. Dunchev, D. K. Drumeva
- ABSTRACT:
This article presents the results obtained from finite element (FE) analysis of the diamond
burnishing process of holes in sliding bearingsmade of CuAl8Fe3 aluminum bronze. For this
purpose, a fully coupled 3D FE model of the studied process was developed. The model makes it
possible to assess both the temperature effect and the stressed and strained state in the surface layers
around the hole. It was found that in diamond burnishing the temperature athole surface pointsis
characterized by a strong gradient, reaching a maximum value , after that it decreases very quickly. Based on the FE results for the equivalent plastic strain C54.284T max,A p distribution in a
depth, it was found that the hardened layer has a thickness of mm75.0 . The diamond burnishing
process provides an intensive compressive zone with useful hoop residual stresses
in the surface layers around the hole in CuAl8Fe3 bronze sliding bearings.MPa340res
max,t
- PAGES:
17-
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FINITE ELEMENT ANALYSIS OF THE DIAMOND BURNISHING PROCESS OF HOLES IN CuAl8Fe3 ALUMINUM BRONZE
- TITLE:
DEVELOPMENT OF HYDROPHILIZED UNSATURATED POLYESTER RESINS BASED ON DIFFERENT TYPES OF MODIFIERS
- AUTHOR(S):
R. Cherkezova, T. Hristova, K. Zafirova
- ABSTRACT:
This work presents the modification of unsaturated polyester resin (UPER) with different types of
hydrophilizing components – sodium hydroxide, sulfur and sulfate-resistant cement. A different type
of hydrophilized unsaturated polyester resin (HUPER) was obtained based on this processing. The
varieties of HUPER so obtained were compared on the basis of their hardening kinetics. When
sodium hydroxide is used as a hydrophilizing agent minimum amounts of sodium hydroxide make it
possible to choose a minimum gelation time. Unlike the sodium hydroxide, the hydrophilizing agent
sulfur demonstrates that the increase in its amount results in lower gelation temperatures and
increases the gelation time. A special feature of the third hydrophilizing agent sulfate-resistant
cement was identified, whose amount does not affect the gelation time, i.e. it is maintained within
certain limits (27-29 min). A comparison of strength values was made. With the hydrophilizing agent
sodium hydroxide the test pieces retain their strength values in a broader range (2.99-4% tensile
elongation, 14.98-18.62 MPa tensile strength, 1056.81-581 MPa Young’s modulus). Where the
hydrophilizing agent is sulfur these values are the lowest, and the sulfate-resistant cement increases
to the greatest extent the tensile strength values (24.19 MPa) and percent tensile elongation values
(8.23%), and to the lesser extent – the Young’s modulus values (389.25 MPa).
- PAGES:
11-
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DEVELOPMENT OF HYDROPHILIZED UNSATURATED POLYESTER RESINS BASED ON DIFFERENT TYPES OF MODIFIERS
