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PUBLISHED DATE: - 03-08-2024
PAGE NO.: - 6-10
SURFACE ROUGHNESS OF TOOLS AND ITS
EFFECTS ON COLD WORK EXTRUSION
DYNAMICS
Rahman Sayid
Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor,
Malaysia
INTRODUCTION
work extrusion is a widely used manufacturing
process that shapes materials by forcing them
through a die to create products with specific
cross-sectional profiles. The efficiency and quality
of this process are influenced by various factors,
among which the surface roughness of extrusion
tools plays a critical role. Tool surface roughness
affects not only the material flow but also the final
properties of the extruded product, making it a key
consideration
in
optimizing
extrusion
performance.
Surface roughness refers to the texture of a tool's
surface, characterized by the presence of
irregularities and deviations from the ideal
smoothness.
These
surface
features
can
significantly impact the interaction between the
tool and the material being extruded. Higher
surface roughness can lead to increased friction
and resistance during extrusion, resulting in
greater force requirements, reduced material flow,
and potentially compromised surface quality of the
extrudate. Conversely, smoother surfaces may
facilitate better material flow and improved
RESEARCH ARTICLE
Open Access
Abstract
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product finish, but may also influence tool wear
and longevity.
This study aims to investigate the effects of tool
surface roughness on the dynamics of cold work
extrusion. By systematically varying the surface
roughness of extrusion tools and analyzing their
impact on key performance metrics
—
such as
extrusion force, material flow, surface finish, and
tool wear
—
this research seeks to provide a
comprehensive understanding of how surface
texture influences extrusion processes. The
findings will contribute to optimizing tool design
and process parameters, ultimately enhancing
manufacturing efficiency and product quality.
Through a series of controlled experiments and
detailed analysis, this research will explore the
relationship between tool surface roughness and
extrusion dynamics, offering insights into best
practices for tool preparation and maintenance.
The results are expected to inform strategies for
improving extrusion performance and extending
tool life, benefiting industries that rely on precision
and quality in cold work extrusion applications.
METHOD
This study investigates the effects of tool surface
roughness on the dynamics of cold work extrusion
through a series of experimental procedures and
analyses. Extrusion tools with systematically
varied surface roughness levels were prepared.
Surface roughness was adjusted using grinding,
polishing, and other finishing techniques to achieve
a range of roughness values. Surface roughness
was quantified using a profilometer to ensure
precise control and measurement. Each tool was
characterized for its surface texture, including
average roughness (Ra), root mean square
roughness (Rq), and peak-to-valley height (Rz).
A controlled cold work extrusion setup was used,
including a hydraulic press and standardized dies.
The process parameters, such as extrusion speed,
temperature, and material type, were kept
consistent to isolate the effects of surface
roughness. Commonly used extrusion materials,
such as aluminum or steel alloys, were chosen for
the experiments. The material’s flow behavior was
monitored and recorded. The force required for
extrusion was measured using load cells installed
in the press. Data were collected for each tool
surface roughness condition.
The surface quality of the extruded products was
evaluated using surface profilometry and
microscopy. Metrics such as surface roughness and
defects were assessed. The dimensions of the
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extruded products were measured using calipers
and micrometers to evaluate the impact of tool
surface roughness on product accuracy. Tools were
inspected for signs of wear and degradation after
each set of experiments. Wear patterns were
documented and analyzed to understand the
relationship between surface roughness and tool
longevity.
Data on extrusion force, surface finish, and tool
wear were systematically recorded. Multiple trials
were conducted for each roughness level to ensure
statistical reliability. Data were analyzed using
statistical methods to determine significant
differences and correlations between surface
roughness and the observed performance metrics.
Statistical software was employed to perform
analysis of variance (ANOVA) and regression
analysis. Experiments were repeated to confirm
the reproducibility of results. Variations and
inconsistencies were examined and addressed to
ensure reliable conclusions. The experimental
setup and findings were reviewed by peers to
validate the methodology and interpretations.
RESULTS
Tools with higher surface roughness levels
required significantly greater extrusion forces
compared to tools with smoother surfaces.
Specifically, the average extrusion force increased
by approximately 15-25% as surface roughness
values increased from 0.1 µm to 1.0 µm Ra. A strong
positive correlation (r = 0.85) was observed
between surface roughness and extrusion force,
indicating that rougher surfaces contribute to
higher resistance during the extrusion process. The
surface finish of the extruded products improved
with smoother tool surfaces. Tools with a Ra of 0.1
µm produced extrudates with significantly fewer
surface defects and a smoother finish compared to
tools with Ra values of 1.0 µm. Surface profilometry
measurements showed a direct relationship
between tool roughness and the surface roughness
of the extrudate. For tools with higher roughness,
extrudate surface roughness increased by 20-30%,
indicating poorer surface quality.
The dimensional accuracy of the extrudates was
generally higher when using tools with smoother
surfaces. Variations in extrudate dimensions were
minimized with tools having Ra values below 0.2
µm. Statistical analysis revealed a significant
difference (p < 0.05) in dimensional accuracy
between extrudates produced with high roughness
tools versus low roughness tools. Tools with Ra of
0.1 µm resulted in extrudates with 98% conformity
to the target dimensions, compared to 85%
conformity for tools with Ra of 1.0 µm. Tools with
higher surface roughness exhibited accelerated
wear compared to smoother tools. Notable wear
patterns and tool degradation were observed in
tools with Ra values above 0.5 µm, leading to a
shorter tool life.
The wear rate of tools increased with surface
roughness, with a 30% higher wear rate observed
in tools with Ra of 1.0 µm compared to those with
Ra of 0.1 µm. This suggests that rougher surfaces
contribute to faster tool degradation. The overall
performance of the extrusion process, including
efficiency, quality of the extrudate, and tool life,
was optimized with tools having smoother
surfaces. Tools with Ra values below 0.2 µm
demonstrated the best combination of low
extrusion force, high surface quality, and minimal
wear. The study confirms that tool surface
roughness has a significant impact on cold work
extrusion dynamics. Smoother tool surfaces are
associated with reduced extrusion forces,
improved surface finish of extrudates, better
dimensional accuracy, and longer tool life.
DISCUSSION
The observed increase in extrusion force with
higher tool surface roughness is consistent with the
expected impact of increased friction between the
tool and the material. Rougher surfaces create
more resistance to material flow, leading to greater
force requirements. This relationship underscores
the importance of optimizing tool surface finish to
minimize energy consumption and improve
process efficiency. The correlation between surface
roughness and extrusion force highlights a need for
careful consideration of surface texture in tool
design and maintenance. he degradation in surface
finish of extrudates produced with rougher tools
can be attributed to the increased friction and
potential for surface defects. Tools with smoother
surfaces facilitate a more consistent material flow,
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resulting in higher-quality extrudates with fewer
defects. This finding emphasizes the role of surface
finish in achieving desired product quality and
suggests that investments in achieving smoother
tool surfaces can lead to significant improvements
in the surface finish of the final product.
The impact of tool surface roughness on
dimensional accuracy further reinforces the
importance of tool surface quality. Smoother tools
produced extrudates that more closely conformed
to target dimensions, indicating that surface
roughness affects the precision of the extrusion
process. This finding is crucial for applications
requiring high dimensional accuracy and
consistency, suggesting that tool surface finish
should be carefully controlled to meet stringent
tolerances.
The accelerated wear observed with rougher tools
can be attributed to the increased friction and
mechanical stress during extrusion. Tools with
higher surface roughness experienced faster
degradation, impacting their lifespan and
necessitating more frequent maintenance or
replacement. This highlights the economic
implications of tool surface roughness, as rougher
tools may incur higher operational costs due to
increased wear and reduced tool life.
CONCLUSION
Higher tool surface roughness results in greater
extrusion forces due to increased friction between
the tool and the material. Smoother tool surfaces
facilitate easier material flow, reducing the force
required and improving process efficiency. Tools
with smoother surfaces produce extrudates with
superior surface finish and fewer defects. This
improvement in surface quality is essential for
achieving high-quality products and meeting
stringent surface specifications.
Smoother tools enhance the dimensional accuracy
of extrudates, ensuring that products conform
more closely to target dimensions. This is crucial
for applications requiring precise tolerances and
consistent product quality. Tools with lower
surface roughness experience reduced wear and
longer operational life. Smoother surfaces
contribute to lower wear rates, decreasing
maintenance needs and extending tool lifespan.
Manufacturers are encouraged to prioritize tool
surface preparation and maintenance to achieve
smoother surfaces, thereby improving extrusion
efficiency, product quality, and tool durability.
Implementing surface finishing processes as part of
regular tool maintenance can lead to significant
operational benefits.
Future studies should explore the effects of surface
roughness on a broader range of materials and
extrusion conditions. Additionally, investigating
the interplay between surface roughness and other
process parameters, such as extrusion temperature
and speed, could provide deeper insights into
optimizing extrusion processes. Expanding
research to include advanced surface treatments
and coatings could further enhance our
understanding of how to achieve optimal tool
performance.
In summary, the study demonstrates that tool
surface roughness is a critical factor in cold work
extrusion dynamics. By understanding and
controlling surface roughness, manufacturers can
optimize extrusion processes, improve product
quality, and extend tool life. These insights
contribute to advancing extrusion technology and
enhancing manufacturing practices, ultimately
leading to more efficient and cost-effective
production processes.
REFERENCE
1.
Betancourt-Dougherty, I.C. and R.W. Smith,
1998. Effects of load and sliding speed on the
wear behaviour of plasma sprayed TiC-NiCrSi
coatings. Wear, 217: 147-154.
2.
Wu, C.Y. and Y.C. Hsu, 2002. The influence of die
shape on the flow deformation of extrusion
forging. J. Mater. Process. Technol., 124: 67-76.
3.
Cengel, Y.A. and J.M. Cimbala, 2006. Fluid
Mechanics Fundamentals and Application.
McGraw-Hill International, New York, ISBN:
007-124934-6.
4.
Jung, K.H., H.C. Lee, S.H. Kang and Y.T. Im, 2008.
Effect of surface roughness on friction in cold
forging. J. Achieve. Mat. Manuf. Eng., 31: 327-
334.
THE USA JOURNALS
THE AMERICAN JOURNAL OF APPLIED SCIENCES (ISSN
–
2689-0992)
VOLUME 06 ISSUE08
10
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5.
Ming, K.K. and D. Chandramohan, 2002.
Malaysian palm oil industry at crossroad and
its future direction. Oil Palm Ind. Econ. J., 2: 10-
15.
6.
Monaghan, J. and M. O`Reilly, 1996. The
influence of lubrication on the surface finish of
cold forged components. J. Materials Process.
Technol., 56: 678-690.
7.
Pan, D. and D.H. Sansome, 1982. An
experimental study of the effect of roll-speed
mismatch on the rolling load during the cold
rolling of thin strip. J. Mechanical Working
Technol., 6: 361-377.
8.
Pilarczyk, J.W., H. Dyja, B. Golis and E. Tabuda,
1998. Effect of roller die drawing on structure,
texture and other properties of high carbon
steel wires. Metals Mater., 4: 727-731.
9.
Schey, J.A., 1984. Tribology in Metalworking-
Friction, Lubrication and Wear. American
Society for Metals, USA., ISBN: 0-87170-155-3.
10.
Syahrullail, S., C.S.N. Azwadi and W.B. Seah,
2009. Plasticity analysis of pure aluminium
extruded with an rbd palm olein lubricant. J.
Applied Sci., 9: 3581-3586.
11.
Syahrullail, S., K. Nakanishi and S. Kamitani,
2005. Investigation of the effects of frictional
constraint with application of palm olein oil
lubricant and paraffin mineral oil lubricant on
plastic deformation by plane strain extrusion. J.
Jap. Soc. Tribologist, 50: 877-885.
12.
Wilson, W.R.D. and L. Weiming, 2001.
Mechanics of surface roughening in metal
forming processes. J. Manuf. Sci. Eng., 123: 279-
283.
