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BULETIN ŞTIINŢIFIC, Seria C, Fascicola: Mecanică, Tribologie, Tehnologia Construcţiilor de Maşini SCIENTIFIC BULLETIN, Serie C, Fascicle: Mechanics, Tribology, Machine Manufacturing Technology, ISSN 1224-3264, Volume 2016 No.XXX

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Tribological Performance of Basalt Fiber-PEI Composite Developed Using Hot Compression Technique Varying

K. Subramanian1, R. Nagarajan1, J. Sukumaran2*, W.J. Thangiah1

Abstract: Development of polymer composite for tribological application is a continuous process where improvement in friction and wear characteristics are much appreciated. In this background basalt fabric of plain weave fabric was used in the present research for developing composite based on polyetherimide matrix (PEI) using hot compression technique. Knowing the low friction characteristics of PTFE, a tailor made composite with PTFE filler was made to study the the influence of filler on wear performance of the composite. Besides, properties such as physical, mechanical properties were also been studied for the fabricated composites. The rotating Pin-on-Disc machine was used for the dry sliding wear testing under varying load with the low velocity conditions. Regarding the density and hardness of the Basalt-PEI composites remained the same with the addition of PTFE. However the tribological behaviour has significant difference between the two material. The coefficient of friction has lower values for basalt PEI composite when compared with the Basalt PEI-PTFE composite. At 80 N and 90 N load no significant difference was observed in the friction characteristics between the two materials. The wear rate showed similar behaviour as that of the friction where the basalt PEI composite has better wear resistance when compared with the Basalt PEI-PTFE composite. The comparison with existing literature clearly points out the newly developed basalt-PEI composite stands as a alternative material for glass-PEI composite.

Keywords: Basalt fabric, Dry sliding wear, Polyetherimide composite, 1. INTRODUCTION Use of polymer composites in various applications plays a major role in recent era. The wear performance of these composite is another key area of focus in many industrial sectors. Basalt is a natural material obtained from volcanic rocks lava and it can able to withstand high temperature upto 1700oC. It has a great potential application in textile, structural, thermal, naval, automotive and various kinds of industrial application. Mechanical and Wear behavior of basalt and glass fabric-reinforced epoxy composites have been carried out by using a pin-on-disc machine. The abrading wear mechanisms have also been studied by worn surface analysis using scanning electron microscopy.[1]. In an investigation by Manikandan the mechanical properties of basalt fibre reinforced composites are superior to glass fibre reinforced composites [2]. The study of basalt fiber with thermoplastic has shown major improvement in the mechanical and wear properties. The chopped basalt reinforced with polylactic acid using injection moulding were earlier studied by Tábi for its properties [3].

Polyetherimide is a thermoplastic with good tensile and modulus property which are generally used in automotive parts, microwave application, electrical and electronic parts. Polyetherimide, commercially known as ULTEM resin, is one of the newest high performance engineering thermoplastics. It has a unique combination of thermal, mechanical and electrical (insulating) properties [4]. Composites with polyetherimide and treated carbon fiber were developed and evaluated for tribological properties. Treated carbon fiber based composites exhibited excellent mechanical and tribological properties [5].

The Polytetrafluoroethylene (PTFE) is one of the high mechanical performance filler material used in most of the tribological application. The tribological

behavior of polytetrafluroethylene (PTFE) and PTFE composites with filler materials and various fibers were studied and the improved wear resistance has been reported [6]. Recently, the chemically treated jute fiber hybrid composite with the addition of PTFE as a filler has shown with better performance in high loading wear application [7]. In this work the wear properties of the Basalt and Polyetherimide composite were studied. In addition to that the polytetrafluroethylene is added as a filler material for the same composite and its wear performance is compared with the past literature data of glass composite.

2. MATERIALS USED

The plain woven form of Basalt Fabric GSM (300±30) is used as a primary reinforcement. It was obtained in the form of roll from the Nickunj Eximp Entp P Ltd, Chennai, India. Polyetherimide (PEI) and dichloromethane are obtained from Sigma Aldrich (P) Ltd, Bangalore, India. In addition, the tribo lubricant filler PTFE was also used in the form of particles in the composites to decrease the friction coefficient.

3. FABRICATION OF THE COMPOSITE

Composites were developed with untreated Basalt fabric and PEI matrix based on impregnation method followed by hot compression molding technique. Basalt fabric (100 mm x100 mm) were immersed in the container filled with PEI solution (25 wt/wt% of dichloromethane) for 1 hour followed by drying in normal atmospheric temperature at 35 ºC. Twenty one prepregs were used to prepare composites plate of of 3 mm thickness. The prepregs were placed in the mould cavity of hot compression machine and it is compressed


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at the temperature of 350 ºC. Second specimen is made in the same manner with the addition of PTFE as a filler element in the PEI solution (10 wt% of PEI solution). The test specimens were cut with the help of water jet cutting machine as per required standards for mechanical and tribological testing.Fig1 shows the prepregs and the Basalt/PEI composite.

Fig. 1 Basalt – PEI composite sheet

4. COMPOSITE CHARACTERISATION: 4.1 Density

Density of the prepared composite is measured using Mettler Toledo densitometer. It was used with water as the immersing liquid. Five samples were tested for each condition in the ASTM D792 standard. The average density of the Basalt/PEI composite was 1.0052 g/cm3. The same composite with the addition of PTFE filler is increased to 1.0086 g/cm3. 4.2 Hardness

Hardness measurements were carried out on 3 mm thick specimens as per ASTM D2240 standards on a shore D scale. Indentations were made at several locations for each specimen and the average hardness value was calculated. At least five specimens were tested and the average value of the Basalt/PEI composite is measured as 98.06. The addition of filler materials to the composite causes a marginal improvement in the hardness up to 99.82. 4.3 Friction and Wear

In the present work, the friction and dry sliding wear behavior of Basalt/PEI and Basalt/PEI/PTFE composite samples have been studied in terms of the coefficient of friction and specific wear rate.

A pin-on-disc setup, (as per ASTM G-99 standard, Make: Magnum Engineers, Bangalore) used for the sliding wear and two-body wear tests. The surface of 8mm diameter composite specimen, glued to a pin of 10 mm width and 50 mm length comes in contact with a hardened alloy steel disc with hardness value of 62 HRC and surface roughness (Ra) of 0.54 µm. . The test was conducted on a track of 50 mm diameter for a

specified test duration, load and velocity. The specimen was initially weighed using a digital electronic balance (0.1 mg accuracy). The test was carried out by applying normal load (70N, 80N, 90N, 100N) and run for a constant sliding distance of 1413 m at 150 rpm. At the end of the test, the sample was again weighed in the same balance. The difference between the initial and final masss was used as a measure for wear loss. The sample in which the specimen perpendicular to Steel disk parallel with respect to the abrading direction is as shown in Fig. 2.

Fig. 2 General representation of Pin-On-Disc wear setup

All the tests were conducted at ambient temperature. The specific wear rate was calculated using following relation:

Ko =∆V /L x D m³/Nm Where Ko is specific wear rate, ∆V is volume

loss, L is load and D is sliding distance.

5. RESULTS AND DISCUSSION Co efficient of friction Basalt/PEI and Basalt/PEI/PTFE composite for various load and sliding conditions are plotted as a function of test duration. It can be seen that for the Basalt/PEI composite, the µ increase slightly with increasing load. From Figure 3 and 4 it is seen that these variation of the wear seems to be within the range and it shows positive behavior of material towards wear resistance. It is found that the almost both the composite attained steady state of friction in fifteen minutes of sliding.

Fig. 3 Coefficient of friction – Basalt/PEI


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Fig. 4 Coefficient of friction – Basalt/PEI/PTFE Inclusion of PTFE in a Basalt reinforced composite, however affect the µ in a unfavorable way. The µ value as low as 0.14 is reached in Basalt/PEI composite, but in the case of PTFE filled it is 0.284. However, for 80 N and 90N loading condition there were no significant difference in friction characteristics between both the materials. It was observed that with the increase in sliding time and load the µ changed very slowly. The frictional value of basalt fabric is compared with glass fiber from literature The µ value of the both the composite found to be very low when compared to glass/PEI and PTFE filled glass/PEI composite [8]. The addition of PTFE in PEI changed the contact condition with the counter surface and also it increases the overall friction value slightly from 0.23 to 0.3. The Basalt/PEI composite showed better performance in terms of Coeffecient of friction. Having selected the same tribological test configuration and load from existing literature allows us to compare the present result with the reported data. It is evident from fig. 5 and fig 6 there is a significant improvement in the friction characteristics of the basalt-PEI composite when compared with the glass fiber PEI composite. A similar case with the influence of the PTFE addition was also compared for the same composite where the basalt fiber composite with PTFE additives has lower friction values thaan the counterpart from literature. Fig. 5 Comparison of CoF - Glass/PEI and Basalt/PEI

Fig. 6 Comparison of CoF- Basalt/PEI/PTFE and Glass/PEI/PTFE Both the composite exhibit the wear rates in the order of 10-15 m3/N.m. In Fig 7 a similar tendency to that of the friction charaacteristics is observed for both the basalt –PEI and Basalt –PEI-PTFE composites. At higher load the PTFE composites showed with increased wear rate. It is clearly seen that the value of specific wear rate is high in the tailor made composite. The values are compared with the glass composite from literature and it found to be very minimum. Fig 8 and 9 clearly indicated that the Basalt will be the clear alternative solution for glass composite in terms of wear. Fig. 7 Comparison of Specific wear rate of Basalt/PEI and Basalt/PEI/PTFE Fig. 8 Comparison of Specific wear rate of Glass/PEI and Basalt/PEI


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Fig. 9 Comparison of Specific wear rate of Basalt/PEI/PTFE and Glass/PEI/PTFE 6. CONCLUSION

In the present research an attempt was made to introduce PEI basalt fibre composites. From the investigation on mechanical and tribological testing the following conclusions can be drawn. • The hardness of the Basalt-PEI composites

remained the same with the addition of PTFE. • The coefficient of friction has lower values for

basalt PEI composite when compared with the Basalt PEI-PTFE composite. However, at 80 N and 90 N loading condition no significant change was observed in the friction characteristics.

• The wear rate showed similar characteristics duplicating the friction behaviour where the basalt PEI composite has better wear resistance when compared with the Basalt PEI-PTFE composite.

• When compared with existing literature the newly developed polymer stands as a candidate material for tribological application

REFERENCES [1] Chairman, C. A., & Kumaresh Babu, S. P. (2013). Mechanical and abrasive wear behavior of glass and basalt fabric-reinforced epoxy composites. Journal of Applied Polymer Science, 130(1), 120–130. [2] Manikandan, V., Winowlin Jappes, J. T., Suresh Kumar, S. M., & Amuthakkannan, P. (2012). Investigation of the effect of surface modifications on the mechanical properties of basalt fibre reinforced

polymer composites. Composites Part B: Engineering, 43(2), 812–818. [3] Tábi, T., Tamás, P., & Kovács, J. G. (2013). Chopped basalt fibres: A new perspective in reinforcing poly(lactic acid) to produce injection moulded engineering composites from renewable and natural resources. Express Polymer Letters, 7(2), 107–119. [4] Bijwe, J., Tewari, U. S., & Vasudevan, P. (1989). Friction and Wear Studies. Engineering, 132, 247 – 264. [5] Tiwari, S., & Bijwe, J. (2013). Various ways to strengthen the fiber-matrix interface for enhanced composite performance. Surface and Interface Analysis, 45(13), 1838–1848. [6] Khedkar, J., Negulescu, I., & Meletis, E. I. (2002). Sliding wear behavior of PTFE composites, 252, 361–369. [7] Subramanian, K., & Nagarajan, R., Sukumaran J, Thangiah W, De Baets P., Dry sliding wear properties of Jute / polymer composites in high loading applications (2015), Mechanical Engieering letters,12 7–18. [8] Tiwari, S., & Bijwe, J. (2013). Various ways to strengthen the fiber-matrix interface for enhanced composite performance. Surface and Interface Analysis, 45(13), 1838–1848.

Authors addresses 1Karthikeyan Subramanian, Assistant Professor, Centre for Composite Materials, Department of Mechanical Engineering, Kalasalingam University, Krishnankoil, Tamilnadu, India, +919003966633, [email protected] 1Rajini Nagarajan,, Associate Professor, Centre for Composite Materials, Department of Mechanical Engineering, Kalasalingam University, Krishnankoil, Tamilnadu, India, +919942139392, [email protected] 1Winowlin Thangiah, Professor, Centre for Composite Materials, Department of Mechanical Engineering, Kalasalingam University, Krishnankoil, Tamilnadu, India, +919894921709, [email protected]

Contact person *2Jacob Sukumaran, Department of Mechanical Construction and Production, Ghent University,, +32466266513, [email protected]

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