Outline of program

We obtain strength properties for space use materials and publish data sheets after evaluation of those data. The materials, sampling, welding and testing methods are discussed in detail by the NIMS Technical Advisory Committee on Space Use Materials Properties. First, a 5-year testing program on the mechanical properties of tensile, Charpy impact, fatigue and fracture toughness was determined. Table 1 shows a temporary publication schedule and contents of the data sheet.

Sampling

To verify the influence of the sampling location and aeolotropy on the material properties, samples were taken from both the inner part and the outer side of all blocks except for the large-size samples for the fatigue test and, in addition, samples in the axial and radial direction were taken for the tensile test and impact test pieces. All samples were obtained by electric discharge machining.

Testing Method

Data were obtained under the ISO 9001 Quality Management Systems using the following testing standards: JIS Z 2277(2000) Tensile Testing Method for Metallic Materials in Liquid Helium, JIS Z 2241(1998) Tensile Testing Method for Metallic Materials, JIS Z 2242(1998) Method of Impact Test for Metallic Materials, ASTM E 813(1989) Test Method for JIc, A Measure of Fracture Toughness and ASTM E 399(1997) Test Method for Plain-Strain Fracture Toughness of Metallic Materials.

Testing machines

Table 3 lists the testing machines for these data sheets. Most machines are installed in NIMS. Fatigue tests at 113K were carried out in NASDA and the tests at 20 K were performed in Nippon Steel Corporation using a machine belonging to NEDO. Examples of testing machines at 4K for tensile, Charpy impact and fatigue tests are presented in Photo 1 a) to c).

Table and Photographs

Table 1. Publication Schedule for the Data Sheet Program
MaterialContentsSchedule
Ti-5Al-2.5Sn ELI large billetFatigue, KIc, Charpy, tensile2003/1
Ti-5Al-2.5Sn ELI smaller billetFatigue, KIc, Charpy, tensile2004/1
Alloy 718 . wrought and castFatigue, KIc, Charpy, tensile2004/3



Alloy 718 EB,955STLow-cycle fatigue, KIc, tensile2003/2
Alloy 718 EBHigh-cycle fatigue, KIc, tensile, da/dn2004/3


Table 2. Testing Facilities
Type of machineTemperatureCapacityNumber available
Tensile test
10 ton1
Charpy impact
500 J1

30 kg-m1
Fracture toughness
50 kN1

100 kN1
Fatigue test
5ton1

10ton1
RT5 ton2
Fatigue test494℃10 ton1
Fatigue test600℃10 ton1
Fatigue test113K10 ton1 (NASDA)
Fatigue test20K10 ton1 (NSC)
Tensile test


Fracture toughness





a) Grips and extensometers for tensile test at cryogenic temperatures



b) Charpy impact testing at liquid helium temperature(4K).



c) Fatigue testing machine with a helium refrigerator for long-term testing at liquid helium temperature.