1. A method for testing the mechanical properties of a specimen having a first contact surface and a second contact surface spaced apart and opposing the first contact surface, the method comprising:
applying forces to the contact surfaces of the specimen to deform the specimen over a period of time and determining the response of the specimen to the forces over time; and
defining a spatial distance between the contact surfaces such that the equivalent gauge length of the specimen is greater than the distance between the contact surfaces.
2. The method according to claim 1, further comprising obtaining a sample of material from an object to be tested and forming the specimen from the sample.
3. The method according to claim 2, further comprising operating on the sample with machine tools to form the specimen.
4. The method according to claim 2, further comprising forming a ring-like shaped specimen from the sample.
5. The method according to claim 1, wherein the first contact surface is either a concave surface or convex surface, and wherein the second contact surface is also either a concave surface or a convex surface.
6. The method according to claim 5, wherein the specimen is symmetrical about a line joining the contact surfaces.
7. The method according to claim 5, wherein the specimen comprises a ring-like shape.
8. The method according to claim 7, wherein the specimen comprises an elliptical shape or a circular shape.
9. The method according to claim 7, wherein the specimen has a flattened elliptical shape having two opposed generally parallel sides and at least one, and preferably two, curved regions linking the parallel sides.
10. The method according to claim 1, wherein the forces applied to the contact surfaces forces the surfaces toward each other.
11. The method according to claim 1, wherein the forces applied to the contact surfaces forces the surfaces away from each other.
12. The method according to claim 1, wherein the forces applied to the contact surfaces is a diametric force which causes the contact surfaces to deform diametrically as a result of the forces being applied to at least a point on the contact surfaces.
13. The method according to claim 12, wherein the diametric force can be either a tension force or a compression force applied to the contact surfaces.
14. The method according to claim 1, wherein the equivalent gauge length of the specimen is significantly greater than the distance between the contact surfaces.
15. The method according to claim 14, wherein the equivalent gauge length of the specimen is greater than or equal to 20 mm.
16. The method according to claim 14, wherein the equivalent gauge length of the specimen is at least two times or four times the distance between the contact surfaces.
17. The method according to claim 1, further comprises heating the specimen to a temperature which is substantially the same as the operating temperature which the sample made from the material would operate at.
18. The method according to claim 1, wherein the specimen is formed from a sample by a sample scooping technique or any other specimen retrieval technique.
19. The method according to claim 1, wherein a force is applied to either the first contact surface or the second contact surface and the other contact surface which does not have the force applied to it is secured to an apparatus for testing the mechanical properties of the specimen, wherein when the force is applied to the first surface or the second contact surface an equal and opposite reactive force is applied to the other contact surface.
20. The method according to claim 19, wherein the first contact surface andor the second contact surface is shaped so as to self-align or self-centre a specimen within the apparatus for testing the mechanical properties of the specimen.
21. The method according to claim 20, further comprising hanging a weight from either the first contact surface or the second contact surface and using the other contact surface which does not have the weight applied to it to react to the force of the weight.
22. The method according to claim 1, wherein testing the mechanical properties of the specimen comprises creep testing the specimen.
23. A specimen for testing the mechanical properties of a material, the specimen comprising:
a first contact surface;
a second contact surface;
wherein the second contact surface opposes the first contact surface and defines an opening in between each surface; and
wherein the specimen defines a spatial distance between the contact surfaces such that the equivalent gauge length of the specimen is greater than the distance between the contact surfaces.
24. The specimen according to claim 23, wherein the first contact surface is either a concave surface or convex surface, and wherein the second contact surface is also either a concave surface or a convex surface.
25. The specimen according to claim 23, wherein the specimen is symmetrical about a line joining the contact surfaces.
26. The specimen according to claim 23, wherein the specimen comprises a ring-like shape.
27. The specimen according to claim 26, wherein the specimen comprises an elliptical shape, or a flattened elliptical shape, or a circular shape, or a split-ring shape, or a C-shape, or the like.
28. The specimen according to claim 23, wherein the specimen is formed from a sample of the material by a sample scooping technique or any other specimen retrieval technique.
29. The specimen according to claim 23, wherein the equivalent gauge length of the specimen is significantly greater than the distance between the contact surfaces.
30. The specimen according to claim 29, wherein the equivalent gauge length of the specimen is greater than or equal to 20 mm.
31. The specimen according to claim 29, wherein the equivalent gauge length of the specimen is at least two times or four times the distance between the contact surfaces.
32. The specimen according to claim 23, wherein a force is applied to either the first contact surface or the second contact surface and the other contact surface which does not have the force applied to it is secured to an apparatus for testing the mechanical properties of the specimen, wherein when the force is applied to the first surface or the second contact surface an equal and opposite reactive force is applied to the other contact surface.
33. The specimen according to claim 32, wherein the first contact surface andor the second contact surface is shaped so as to self-align or self-centre a specimen within the apparatus for testing the mechanical properties of the specimen.
34. The specimen according to claim 33, further comprising hanging a weight from either the first contact surface or the second contact surface and using the other contact surface which does not have the weight applied to it to react to the force of the weight.
35. The specimen according to claim 23, wherein testing the mechanical properties of the specimen comprises creep testing the specimen.
36. An apparatus for testing the mechanical properties of a material to determine a creep characteristic of a sample taken from the material, the sample comprising a first contact surface, a second contact surface spaced apart and opposing the first contact surface, applying forces to the contact surfaces of the sample to deform the sample over a period of time, and the sample defines a gap between the contact surfaces such that the effective gauge length of the sample is greater than the distance between the control surfaces, the apparatus comprising:
an apparatus to apply the forces to the contact surfaces to deform the sample over a period of time;
a heating device to heat the sample; and
a processor to calculate a steady state time dependent deformation rate to determine a creep strain rate.
37. A method of forming a sample from a material, the sample being used for testing the mechanical properties of the material, the method comprising:
extracting the sample from the material;
forming the sample into a test specimen having a first contact surface, a second contact surface spaced apart and opposing the first contact surface;
applying forces to the contact surfaces of the specimen to deform the specimen over a period of time and determining the response of the specimen to the forces over time; and
defining a spatial distance between the contact surfaces such that the equivalent gauge length of the specimen is greater than the distance between the contact surfaces.
38. A process for producing a product from a production plant comprising:
operating the plant to produce the product;
checking the expected operational life of a component of the plant by:
(i) obtaining a sample of the material of a component of the plant, and forming from the sample a specimen in accordance to claim 23;
(ii) performing a creep test on the specimen using the method according to claim 1;
determining that the component has a remaining safe operational life; and
continuing to produce more product, using the component in the future.
39. The process according to claim 38, wherein the product is electricity and the plant is an electricity generating plant.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for programming a non-volatile memory device including a plurality of memory cells, the method comprising:
(a) applying a first voltage to a first word line to program a plurality of memory cells associated with the first word line, the first word line being one of word lines in a word line switching unit that is coupled to a memory cell block, the word line switching unit having N word lines, each word line being associated with a plurality of memory cells;
(b) determining whether or not the first word line is an Nth word line in the word line switching unit, the Nth word line being a word line that is provided closest to a drain select line;
(c) if the first word line is determined not to be the Nth word line, applying a first program-verify voltage to the first word line to determine whether or not the programming has been successful;
(d) if the programming is determined to have been successful in the step (c), applying the first voltage to a second word line in the word line switching unit to program a plurality of memory cells associated with the second word line; and
(e) if the first word line is determined to be the Nth word line in the step (b), applying a second program-verify voltage to the first word line to determine whether or not the programming has been successful.
2. The method as claimed in claim 1, further comprising:
(f) determining whether or not the second word line is an Nth word line in the word line switching unit; and
(g) if the second word line is determined to be the Nth word line, applying the second program-verify voltage to the second word line to determine whether or not the programming has been successful.
3. The method as claimed in claim 1, further comprising:
if the first word line is determined to have been programmed unsuccessfully, applying a second voltage to the first word line to reprogram the memory cells associated with the first word line, the second voltage being higher than the first voltage.
4. The method as claimed in claim 1, further comprising:
if the programming is determined to have been unsuccessful in the step (e), applying a second voltage to the first word line to reprogram the memory cells associated with the second word line, the second voltage being higher than the first voltage.
5. The method as claimed in claim 1, wherein the second program-verify voltage is higher than the first program-verify voltage.
6. The method as claimed in claim 1, wherein the second program-verify voltage is about 1.2 V, and the first program-verify voltage is about 1 V or less.
7. The method as claimed in claim 6, wherein the first program-verify voltage is 1.0V, 0.8 V, or less.
8. The method as claimed in claim 1, wherein the memory cells associated with the first word line are multi-level cells or a single level cells.
9. The method of claim 1, wherein the non-volatile device is a NAND flash memory device.
10. A method for programming a non-volatile memory device, the method comprising:
applying a first program-verify voltage to a first word line to determine whether or not memory cells associated with the first word line have been programmed successfully; and
applying a second program-verify voltage to a second word line to determine whether or not memory cells associated with the second word line have been programmed successfully, the second program-verify voltage being different from the first program-verify voltage,
wherein the first and second word lines are associated with the same word line switching unit.
11. The method of claim 10, wherein the non-volatile memory device is a NAND flash memory device, the first and second word lines being provided between a source select line and a drain select line.
12. The method of claim 11, wherein N word lines are associated with the word line switching unit and the second word line is an Nth word line.
13. The method of claim 11, wherein the word switching unit is associated with at least 16 word lines and the second word line is a word line that is closest to the drain select line.
14. The method of claim 13, wherein the first program-verify voltage is lower than the second program-verify voltage.
15. The method of claim 11, wherein the first and second word lines are associated with a given cell block in the non-volatile memory device, wherein at least two different program-verify voltages are applied to a plurality of word lines that are associated the given cell block to determine whether or not memory cells of the given cell block have been programmed successfully.
16. The method of claim 15, wherein the first program-verify voltage is 1 volt, 0.8 volt, or less, and the second program-verify voltage is 1.2 volt.
17. The method of claim 15, wherein the at least two different program-verify voltages are used to reduce the differences in threshold voltages of the memory cells in the given cell block.
18. The method of claim 15, wherein threshold voltages (Vt) of the memory cells are controlled by using an incremental step pulse program (ISPP) technique.