Thermal Effect on Mechanical and Tribological Performance of Polyether-Ether-Keton

IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 11, 2016 | ISSN (online): 2321-0613

Thermal Effect on Mechanical and Tribological Performance of Polyether-Ether-Keton Karpe Ganesh G1 Dr. C.L. Dhamejani2 1 P.G. Student 2Principal 1,2 Department of Mechanical Engineering 1,2 Jaihind College of Engineering, Kuran, Maharashtra, India Abstract— The present work describes the development of polymer composites consisting of Polyether-ether-keton (PEEK). This work reports the wear performance evaluation of a new class of PEEK. The effects various range of temperatures on the tribological properties of PEEK composites were studied under dry friction conditions.

PEEK composites are maximum used as compressor piston rings or valve for their outstanding mechanical and thermal performance at harsh operating conditions, where PTFE composites fail to service. However high wear rate and friction coefficient of pure PEEK limitation its wider use.

Maximum researchers found that PEEK is good in mechanical characteristic but inferior performances of tribological properties. The effect on the friction and wear nature of PEEK polymer composites has been improved, at room temperature. There are various operations performed in industry at elevated temperature on different machines and high wear rate at maximum temperature is a serious problem in a large number of industrial applications. The objective of this work to study the friction and wear properties of PEEK elevated temperature as well as to increase tribological properties of PEEK without loss of mechanical properties at elevated temperature.

Key words: PEEK, PTFE, Elevated, Harsh I. INTRODUCTION Polyether Ether Ketone (PEEK) is a semi-crystalline colorless organic polymer. It is a thermoplastic that has desirably very good mechanical and chemical resistance properties that are retained to high temperatures. It is highly resistant to thermal degradation as well as attack by both organic and aqueous environments. It has superior resistance to wear and dynamic fatigue PEEK (polyether ether ketone) is a high performance engineered polymer with amazing strength and heat resistant properties. PEEK polymer is a very rigid plastic with excellent lubricity. PEEK is naturally tan in color; however it can be pigmented with a wide range of colors for part identification. Thin wall PEEK is more flexible and can be cut to length with a razor blade. PEEK is a linear aromatic polymer which is semi-crystalline and is widely regarded as the highest performance thermoplastic material. PEEK polymers are obtained by step-growth polymerization by the dialkylation of bi-phenolate salts.

Typical is the reaction of 4,4'-difluorobenzophenone with the disodium salt hydroquinone, which is generated in situ by deprotonating with sodium carbonate. The reaction is conducted around 300°C in polar aprotic solvents such as diphenyl sulphone A. Properties of PEEK Ideal stainless steel replacement  Weight  Biocompatibility

             

High tensile strength Lubricity High temperature resistance Excellent purity Outstanding resistance to chemicals, solvents, and fuels Exceptional torsion stability Thermo formable Resistant to gamma radiation High burst pressure High repeat autoclavability (over 3000 cycles) Low flammability value of UL 94 V-0 at 1.45 mm Excellent impact and wear resistance Limiting oxygen index of 35% at 3.2 mm Excellent hydrolysis resistance

B. Standard Unfilled This is a general-purpose grade, which has the highest elongation at break and also the lowest general mechanical properties (tensile strength, flexural strength and flexural modulus) at a given temperature. Unfilled PEEK also has the best impact properties of the PEEK range. Unfilled PEEK is compliant with FDA 21CFR 177.2145 for use in food contact applications.

II. MATERIALS AND METHOD Specimen Compositions S1 PEEK (100%wt) Fig. 1: Properties A. Processing of the Composites The Sample preparation for Wear Test is carried out by  Compounding by micro-compounder  Compounding by Twin screw extruder  Injection moulding III. EXPERIMENTATION

Fig. 1: Wear and Friction Measuring Apparatus.

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Thermal Effect on Mechanical and Tribological Performance of Polyether-Ether-Keton (IJSRD/Vol. 3/Issue 11/2016/130)

IV. CONCLUSION

Fig. 2: Specimen Pin for Wear Testing Ø 10 × 30 mm PEEK WEAR ( µm) Temperature V in ºC ( m/s) 2kg 4kg 8kg 50 ºC 1.4 56.70 66.93 352.05 100 ºC 1.4 273.93 38.56 100.77 150 ºC 1.4 586.86 333.09 502.67 Table 2: Wear of Neat PEEK

The tribological properties of PEEK composites systematically studied under harsh operating condition ie at high load and at temperature. From the result the following conclusions are drawn.  It was observer that wears resistance of PEEK enhanced.  It has been observed that when Pure PEEK is tested at high load and high temperature, the pure PEEK show the wear value (5.21×10-3mm3/m) improvement in mechanical properties of PEEK.  From result it was cleared that PEEK composite can be act as good solid lubricants at low as well as at high loading condition.  PEEK composite is one of the few metals composite that can be considered for use as a true metal replacement for high temperature and heavy load applications.  The outstanding mechanical properties of PEEK composites at high load made it suitable for the most emending applications, but the high cost sometimes limits applications to those where the properties are very necessary.

REFERENCES

Fig. 3: Effects of load on wear properties for PEEK at 50ºC

Fig. 4: Effects of load on wear properties for PEEK at 100ºC

Fig. 3.5 Effects of load on wear properties for PEEK at 150ºC To evaluate the wear performance of PEEK composites at heavy load, wear test were further performed at 20 N, 40N, 80N respectively. It was noticed that the specific wear rate of the two composites at the scales of 10 5 mm3/m was quite low even the temperature of the pin increases than the glass transition temperature of PEEK matrix. (tg =143°c) This excellent property of PEEK composites was attributed to their crystallized phase. This crystallized phase remains immobile across the glass transition and confers on the material excellent material thermal stability and a high continuous service temperature.

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