Vrac Sidjanin Balos 56
Vrac Sidjanin Balos 56
Vrac Sidjanin Balos 56
10, 2014
Abstract: In this paper, an attempt was made to study the dependencies between average
and maximum roughness in relation to material removal rate and specific volume material
removal rate of long-stroke honing in relation to different abrasive grain size tools and
honing speeds. Long-stroke honing was performed on grey cast iron cylinder liners. It was
found that by using a finer grain tool, lower roughness and similar material removal rate is
obtained. Inconsistent relation between average and maximum roughness in relation to
material removal rate and specific volume material removal rate were described by
abrasive grain stress in honing tools. Abrasive grain stress influences the fall-out of
abrasive grains from the tool surface and their uncontrolled movement over the sample –
tool system. This results in a stochastic workpiece material removal, which is more severe
if the abrasive grains are larger in the corresponding tool.
1 Introduction
Automotive industry components, such as cylinder sleeves, crankpins and
camshaft lobes, valve seat and valve guides, valve body, high pressure pump
components, etc. need lubrication, which demands a unique surface texture. This
is achieved by plateau honing, obtained in two machining operations: pre – honing
or rough honing with large abrasive grain size and subsequent finishing or fine
honing with small abrasive grain size [1], [2]. Rough honing induces deep creases
of specific geometry for effective lubricant retention [3], [4]. The smooth surface
between the deep creases are machined to reduce wear and enable sealing -
finishing honing [5], [6]. A typical surface profile obtained by plateau honing is
shown in Figure 1 [7].
– 163 –
D. Vrac et al. The Effect of Honing Speed and Grain Size on Surface Roughness
and Material Removal Rate during Honing
Figure 1
Surface texture profile showing: a) pre-honing profile and b) obtaining final profile by finishing honing [7]
– 164 –
Acta Polytechnica Hungarica Vol. 11, No. 10, 2014
2 Experimental Study
In this study, experimental investigation was done on dry cylinder liners used on
IMR DM-33 tractor diesel engine. Workpiece material used in this study was GJL
250 grey cast iron, in accordance to [21]. Chemical composition, tested by
Beckman DU-2 optical emission spectrometer is given in Table 1. Microstructure
was anylzed after standard metallographic preparation technique and etching with
Nital, by Leitz Orthoplan light microscope (LM), Figure 2. From Figure 2a, it can
be seen that flake graphite belongs to B-type with traces of C-type graphite, and
with IB4 distribution [22]. Metal matrix microstructure consists of pearlite, a
small amount of ferrite and phosphide eutectic, Figure 2b,c. The size of phosphide
eutectic eyes is uniform, forming dense and closed network, Figure 2c. Brinell
hardness was tested by Wolpert DIA Testor Z testing machine, while ultimate
tensile strength was determined by Amsler 40 SZBDA 699 machine. Hardness of
the grey cast iron was 250±5 BHN, while ultimate tensile strength was 280±10
MPa.
Table 1
Chemical composition of GJL-250 grey cast iron [mass %]
C Si Mn P S Cr Fe
2.80 2.21 0.61 0.02 0.02 0.35 balance
– 165 –
D. Vrac et al. The Effect of Honing Speed and Grain Size on Surface Roughness
and Material Removal Rate during Honing
Figure 2
Workpiece material – graphite shape (a), metal matrix microstructure - pearlite + ferrite isles (b) and
phosphide eutectic network (c)
Input parameters, tool specifications and work piece dimensions were as follows:
Input parameters:
Tool specification:
Pre- and finishing honing head: HLD-Nagel with six honing stones
Honing stones [23, 24]:
– 166 –
Acta Polytechnica Hungarica Vol. 11, No. 10, 2014
Diameter D=94.478+0.025(mm)
Length L=216-0.2(mm)
Figure 3
Honing tool with finishing honing stones
Pre-honing, which was the main subject of this work, was performed by applying
three tool honing speeds: 0.93; 1.02; 1.11 m/s. Tool grain size and honing speeds
were correlated to surface structure parameters and material removal rate
parameters. Surface structure parameters (Rmax; Ra) were obtained with Rank
Taylor Hobson Talysurf 6 profilometer, by using PMMA stamps. Material
removal rate parameters, such as material removal rate (Q) and specific volume
material removal rate (z) were found analytically. Honing material removal rate
may be defined as the volume of the material cut in a second. Material removal
rate may be expressed as:
Qw=Aava+Atvt+Anvn (1)
where Aa, At, An are active contact areas between the tool and the work piece, va, vt,
vn axial, tangential and normal honing speed components. Specific volume
material removal rate [mm3/mm2s] may be expressed as:
𝛥𝑉𝑊
Q’w, = (2)
𝑡∙𝐴𝐻
where: ΔVw is material volume removed [mm3], t honing time [s] and AH –
honing stone working surface [mm2].
– 167 –
D. Vrac et al. The Effect of Honing Speed and Grain Size on Surface Roughness
and Material Removal Rate during Honing
3 Results
– 168 –
Acta Polytechnica Hungarica Vol. 11, No. 10, 2014
Figure 4
The dependence between average roughness Ra and material removal rate Q by using D181 (a) and
D151 tool (b)
Figure 5
The dependence between maximum roughness Rmax and material removal rate Q by using D181 (a) and
D151 tool (b)
A considerable difference between D181 and D151 tool was noticed in trend lines
obtained from centroids as well. Trend lines that describe roughness – material
removal rate dependence obtained with D181 tool are more inclined compared to
corresponding trend lines obtained with D151 tool, Figs. 4-7. It should be noted,
that the trendlines obtained from the centroids of experiments conducted with
D151 tool are nearly horizontal, which is close to the ideal, horizontal trend that
indicates no change in roughness parameter at higher material removal rate
parameter.
– 169 –
D. Vrac et al. The Effect of Honing Speed and Grain Size on Surface Roughness
and Material Removal Rate during Honing
Figure 6
The dependence between average roughness Ra and specific volume material removal rate z by using
D181 (a) and D151 tool (b)
Figure 7
The dependence between maximum roughness Rmax and specific volume material removal rate z by
using D181 (a) and D151 tool (b)
– 170 –
Acta Polytechnica Hungarica Vol. 11, No. 10, 2014
Figure 8
Surface texture obtained with D181 tool, where white arrow shows damage that may be caused by a
fallen out diamond abrasive grain or grain fragment (SEM)
Figure 9
D151 honing stone surface: a) A relatively smooth surface with a small number of abrasive grains can
be observed in an unused tool; b) An used D151 honing stone surface. Long white arrow shows the
exposed abrasive grain, short white arrows show abrasive grain pits and black arrow points at a surface
damage that may be the result of a fallen out abrasive grain
Surface texture of D151 honing stones before and after pre - honing process is
shown in Figure 9. In Figure 9a, an undamaged surface can be observed, with a
small number of exposed abrasive grains. On the other hand, in Figure 9b, a
number of exposed abrasive grains are visible. Furthermore, some abrasive grains
appear exposed (long white arrow), while some empty pits are visible (short white
arrow).
– 171 –
D. Vrac et al. The Effect of Honing Speed and Grain Size on Surface Roughness
and Material Removal Rate during Honing
4 Discussion
Trends shown in Figs. 4-7, related to triangle and line segment size are the result
of larger differences between the obtained results within the same honing speed.
These differences are predominantly related to roughness parameters. The highest
differences within the same honing speed were noticed at maximum roughness by
using a coarser grained D181 tool, Figs. 5 and 7, where this difference amunts up
to 118 %. On the other hand, differences between maximum roughnesses by using
a finer grained D151 tool were smaller, however, even in this case, the maximum
difference reached 42%. If average roughness is considered, for both D181 and
D151 tools, maximum differences are closer to maximum roughness differences
obtained with D151 tool. In general, the values of Ra and Rmax are comparable to
the values obtained by Stout and Davies [25] as well as Stout and Spedding [26].
Material removal rate parameters shown in Figures 4-7 do not show a similar
differences within the same honing speed as roughness parameters - maximum
differences are within 10%.
Previous discussion indicates that by applying D181 tool, both material removal
rate and specific volume material removal rate may be increased, but at the
expense of increased roughness. However, by using D151 tool, trend line is almost
horizontal, which means that an increased material removal rate and specific
volume material removal rate can be obtained without a significant impact on
average and maximum roughness. That means, material removal rate and specific
volume material removal rate of the surface machined by a finer grain tool (D151)
may have equal roughness parameters as with coarser grained tool (D181), but
providing 15-20% higher material removal rate and specific volume material
removal rate, Figures 4-7.
Although angle between trend lines and horizontal axis does indicate roughness –
material removal rate dependence, which gives valuable informations about one of
the most significant advantages of long-stroke honing and its most notable
drawback, material removal rate, a special attention must be payed to relatively
high differences between roughness parameters, most importantly maximum
roughness, as key parameters of the surface texture obtained by long-stroke
honing. When honing speed influence on roughness dispersion is considered,
different results are obtained regarding maximum and average roughness.
Maximum roughness differences within one experimental setup reach a maximum
at medium honing speed at 1.02 m/s, after that, differences drop considerably.
This drop is much more significant when a finer grained D151 tool is used.
Average roughness obtained with both R181 and R151 tools rises with the
increase in honing speed. One possible explanation of these phenomenons is tool-
removed material interaction during honing. Namely, at higher honing speeds, the
removed material aids in abrasive grain retention in the tool, promoting a decrease
in maximum roughness. However, at higher honing speeds, more heat is produced
in the bonding material, leading to a higher abrasive grain stress, where abrasive
– 172 –
Acta Polytechnica Hungarica Vol. 11, No. 10, 2014
grains can fall out from the tool. Fragments produced this way may influence an
increased average roughness due to the induction of additional creases in the
workpiece material, which can have an unpredictable shape, direction and profile,
having an adverse effect on the lubricant flow. Clearly, a fallen – out grain would
not follow the kinematic path of the grains still placed into the tool, but they
would rather follow an unregular path, not neccessarilly straight. A crease shown
by white arrow in Figure 8 is a representative example. The unregular grain or
grain fragment movement in the workpiece – tool system is supported by the
observations in the honing stone surface, Figure 9. A black arrow points at an
unregular abrasive grain path in the tool surface, that can be the result of the
abrasive grain fall out from the bakelite matrix. The appearence of the curved path
in Figure 9b is similar to that shown in Figure 8 that refers to the workpiece
surface. This supports the theoretical explanation of obtaining an increased
roughness and irregular creases by applying high-end honing speeds tested in this
study. The stochastic component is more pronounced if honing speeds are higher,
as well as if the abrasive grains are larger.
Conclusion
In accordance to experimantal analys of GJL250 grey cast iron has shown that:
Centroid derived trendlines indicate a stronger influence of honing speed
on roughness-material removal rate dependance for a coarser-grained
than a finer-grained pre-honing tool. This means a finer surface texture
for the same material removal rate is obtained with a finer abrasive grain
tool. On the other hand, for the same rughness parameters (average and
maximum roughness), a higher productvity and specific volume material
removal rate can be obtained. This increase in material removal rate is
between 15 and 20%.
Average and maximum pre-honing roughness results show a more
significant differences within one experiment with a constant honing
speed for a coarser-grained than a finer-grained pre-honing tool.
Inconsistencies in peak differences between the results obtained at the
same honing speed may be explained by abrasive grain stress.
Abrasive grain stress may influences the falling out of abrasive grains
from the honing stone. These grains have unpredictable trajectories over
the workpiece surface, making irregular creases. As these creases are
more pronounced, their impact on inconsistent lubricant flow is higher.
Finer grained tool and higher honing speed are beneficial for achieving higher
material removal rate at a moderate rise of roughness parameters.
– 173 –
D. Vrac et al. The Effect of Honing Speed and Grain Size on Surface Roughness
and Material Removal Rate during Honing
References
[1] P. Stark: Feinbearbeitung in der Automobilindustrie, In Jahrbuch Schleifen,
Honen, Läppen und Polieren, Vulkan-Verlag, Essen, Germany, 1985, pp.
458-496
[2] MC. Malburg, J. Raja, DJ. Whitehouse, Characterization of Surface
Texture Generated by Plateau Honing Process, CIRP Annals -
Manufacturing Technology, 42 (1993) pp. 637-639
[3] YB. Guo, Y. Zhang, JA. Zhong J. A. and K. Syoji: Optimization of Honing
Wheel Structure Parameters in Ultra-Precision Plane Honing, Journal of
Materials Processing Technology, 129 (2002) pp. 96-100
[4] IB. Corral, JV. Calvet and MC. Salcedo: Use of Roughness Probability
Parameters to Quantify the Material Removed in Plateau-Honing,
International Journal of Machine Tools & Manufacture, 50 (2010) pp. 621-
629
[5] D. Vrac, L. Sidjanin and D. Milikic: The Influence of Honing Regime on
Quality of Surface Finished by Honing, Proceedings of XXXII Conference
on production engineering with forign partcipants, Novi Sad, Serbia (2008)
pp. 117-120
[6] P. Pawlus, T. Cieslak and T. Mathia: The Study of Cylinder Liner Plateau
Honing Process, Journal of Materials Processing Technology, 209 (2009)
pp. 6078-6086
[7] D. Vrac: Final Machining Process of Cylinder Liner of Internal-
Combustion Engine, PhD thesis, Faculty of Technical Sciences,
Department for Production Engineering, University of Novi Sad, Serbia,
2007
[8] DIN 8589 Standard: Manufacturing processes chip removal – Part 0:
General; Classification, subdivision, terms and definitions, Berlin,
Germany (2003)
[9] E. Sech and J. Strobel: Diamant fluidstrahel gätthonung. Friedrich Vieweg
& Sohn Verlagsgeselschaft, 2001
[10] D. Vrac: The Characterization of Honing Surface Roughness by Surface
Reaction RSM Method, Proceedings of 9th international scientific
conference MMA 2006 - Flexible technologies, Faculty of Novi Sad,
Serbia: (2006) pp. 35-36
[11] JK. Tyagi and VC. Krishnamurthy: On Surface Quality of Honed Surfaces,
Proceedings of the 5th International Conference on Production Engineering,
Tokyo, Japan (1984) pp. 708-713
[12] D. Vrac: The Influence of Cylinder Machining on Techno-Exploitation
Properties of a Typical Diesel Engine, M. S. Thesis. Faculty of Technical
– 174 –
Acta Polytechnica Hungarica Vol. 11, No. 10, 2014
– 175 –