Fortron PPS Product Brochure (B240) - Hi Polymers

Fortron ®
Polyphenylene sulphide (PPS)
For Fortron the fatigue strength at 10 7 load cycles is
about 15 to 30% of the tensile strength determined in
the tensile test. For fairly brittle products with high
strength and low elongation the tensile strength is
identical to the tensile stress at break.
Fig. 17 shows the behaviour of Fortron 1140L4 and
6165A4 in the fluctuating tensile stress range at 23°C;
fig. 18 shows the same at 90°C.
Fig. 14 · Flexural creep modulus of Fortron
1140L4 and 6165A4 at 80 and 120°C (measured
with an outer-fibre stress b = 50 MPa)
20 000
MPa
15 000
1140L4
6165A4
The fatigue strength falls with increasing temperature
(fig. 18) and load cycle frequency as well as with the
existence of stress peaks in notched components.
The Wöhler curves for fluctuating flexural stress for
four Fortron grades are shown in fig. 19.
+
–
Fig. 16 · Stress ranges in fatigue tests
m a
m a
u 0
m a
m 0
m
compression
– + tension
a
m a
u 0
m a m a m a
m a
time
Flexural creep modulus
10 000
5 000
range for fluctuating
stresses
(under compression)
range for alternating
stresses
range for fluctuating
stresses
(under tension)
Fig. 17 · Wöhler curve for Fortron 1140L4 and
6165A4, determined in the fluctuating tensile
stress range at 23°C
Flexural creep modulus
Fig. 15 · Flexural creep modulus of Fortron
1140L4 and 6165A4 at 200°C (measured
with an outer-fibre stress b = 30 MPa)
6 000
MPa
5 000
4 000
3 000
2 000
1000
0
10 –2 10 –1 10 0 10 1 10 2 10 3 h 10 4
Time under stress
0
10 –2 10 –1 10 0 10 1 10 2 10 3 h 10 4
Time under stress
1140L4
6165A4
Fatigue strength under
fluctuating tensile stress
Fatigue strength under
fluctuating tensile stress
60
MPa
50
40
30
20
10
0
time
0
10 2 10 3 10 4 10 5 10 6 10 7 10 8
Fig. 18 · Wöhler curve for Fortron 1140L4 and
6165A4, determined in the fluctuating tensile
stress range at 90°C
40
MPa
30
20
10
m = a
1040L4
6165B4
m = a
6165B4
1040L4
Stress cycles N
0
time
0
10 2 10 3 10 4 10 5 10 6 10 7 10 8
Stress cycles N
Test temperature 23°C
Stress cycle frequency 5 Hz
Test temperature 90°C
Stress cycle frequency 5 Hz
16