The effect of hardness of grey cast iron flat specimen on its wear and friction on the
contact were characterised with the presence
of vegetable oil as biolubricant. Prior to the
tribological test, the as
-
received grey cast iron flat specimen hardness was characterised. Friction
and wear tests were then conducted using a ball
-
on
-
flat reciprocating sliding contact.
The one
-
way analysis
of variance (ANOVA) was used to determine the significance of friction and wear
data with a 95% significance level.
The wear scars after the test were then characterised by
surface roughness and wear mechanism. The microstructure and elemental analysis we
re also
reported. The average value of hardness was 210 HV with a large difference between minimum
(185 HV) and maximum (250 HV) values.
The friction and wear performance of grey cast iron
specimens with soybean oil varied with its hardness.
The specimens
with higher hardness gave
lower friction coefficient and greater wear resistance than the lower hardness specimens.
The
difference in coefficient of friction produced between high hardness specimens (COF = 0.122)
and low hardness specimens (COF = 0.140) wa
s 17%. In terms of mass loss, the low hardness
2
specimens (mass loss = 50.38 mg) and the high hardness specimens (mass loss = 12.90 mg)
produced a difference of 74%.
It is shown that, with soybean oil lubricant, the grey cast iron
specimen can produce wide
range of tribological data especially on mass loss due to its hardness
distribution. The influence of soybean oil lubrication in this work is less in improving the wear
resistance (about 7%), but greater for friction reduction (about 24%) compared to an un
lubricated
grey cast iron surface. The hardness of grey cast iron specimen is an important parameter that
needs to be specifically measured and controlled on the contact due to wide hardness distribution
of grey cast iron may produce variation in tribologi
cal data.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)