CN108982220B - Method for evaluating local mechanical property of metal additive manufacturing formed part - Google Patents
Method for evaluating local mechanical property of metal additive manufacturing formed part Download PDFInfo
- Publication number
- CN108982220B CN108982220B CN201810929910.6A CN201810929910A CN108982220B CN 108982220 B CN108982220 B CN 108982220B CN 201810929910 A CN201810929910 A CN 201810929910A CN 108982220 B CN108982220 B CN 108982220B
- Authority
- CN
- China
- Prior art keywords
- micro
- sample
- displacement
- compression
- compressed sample
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
Abstract
The invention discloses a method for evaluating the local mechanical property of a metal additive manufacturing formed piece, which comprises the following steps of: acquiring a tiny compressed sample from a key position; performing a compression test on the tiny compression sample to obtain a force-displacement curve of the tiny compression sample; correcting the force-displacement curve and converting the corrected force-displacement curve into a stress-strain curve of a micro compression sample; and determining the mechanical properties of the micro-compression sample according to the stress-strain curve, wherein the mechanical properties comprise elastic modulus and yield strength. Therefore, the mechanical property of the key position of the metal additive manufacturing forming piece is represented by the tiny compression sample obtained from the key position of the additive manufacturing forming piece, and the problem that the local property of the part cannot be reflected by the standard sample is solved. The selected dimension of the micro compressed sample not only has representativeness of macroscopic mechanical property, but also can accurately reflect the micro-area mechanical property of the designated height and the designated direction.
Description
Technical Field
The invention relates to the technical field of material mechanics and testing, in particular to a method for evaluating local mechanical property of a metal additive manufacturing forming piece.
Background
Additive manufacturing (3D printing or rapid prototyping) of the related art uses a high-energy beam (e.g., an arc, laser, or electron beam) as a heat source and rapidly moves the heat source according to the geometric features of the part to melt a metal feedstock (e.g., wire or powder) to achieve layer-by-layer additive forming. However, since the metal additive manufactured product undergoes numerous melting and solidification processes, the heat source acting area is small, the thermal history of the local area is extremely complicated due to the influence of various factors such as heat source power, scanning strategy, component form and size, and the like, significant differences of microstructures at different heights and in different directions are caused, and non-uniformity of mechanical properties of the local area is directly caused.
At present, there are two main methods for evaluating the mechanical properties of an additive manufacturing formed part: one is to print the tensile sample while manufacturing the part, but the printed tensile sample can only reflect the macroscopic mechanical properties of the sample and cannot represent the local mechanical properties of the part in a specific height and a specific direction. Another method is to cut a microcolumn of nanometer or micrometer scale on a material by using a Focused Ion Beam (FIB) method and the like, and perform a compression test, but the microcolumn sample cut by this method often generates a scale effect due to too small size, and the result obtained by this method does not reflect the macroscopic mechanical properties of the sample, and the operation is complicated.
Therefore, it is a problem to be solved urgently how to specifically and accurately evaluate the mechanical properties of an additive manufacturing formed part by performing a test on a proper scale according to the forming characteristics of additive manufacturing.
Disclosure of Invention
The embodiment of the invention provides a method for evaluating local mechanical properties of a metal additive manufacturing formed piece.
The method for evaluating the local mechanical property of the metal additive manufacturing formed piece comprises the following steps:
determining a height and a direction of a strategic location of the metal additive manufacturing form;
acquiring a tiny compressed sample from the key position;
performing a compression test on the micro-compressed sample to obtain a force-displacement curve of the micro-compressed sample;
correcting the force-displacement curve and converting the corrected force-displacement curve into a stress-strain curve of the micro compression sample; and
and determining the mechanical properties of the micro compression sample according to the stress-strain curve, wherein the mechanical properties comprise elastic modulus and yield strength.
According to the method for evaluating the local mechanical property of the metal additive manufacturing forming piece, aiming at the characteristic that the structure and the mechanical property of the metal additive manufacturing forming piece are highly localized, the mechanical property of the key position of the metal additive manufacturing forming piece is represented by the tiny compression sample obtained from the key position on the additive manufacturing forming piece, and the problem that the standard sample cannot reflect the local property of a part is solved. The selected dimension of the micro compressed sample not only has the representativeness of macroscopic mechanical property, but also can accurately reflect the micro-area mechanical property of the specified height and the specified direction.
In some embodiments, the micro-compressed sample is in a column shape, the cross section of the micro-compressed sample is in a circular shape, the cross section is perpendicular to the height direction of the micro-compressed sample, the height of the micro-compressed sample is greater than 0.5mm and less than or equal to 3mm, the ratio of the height of the micro-compressed sample to the diameter of the cross section is 1-3, and the area of the cross section is greater than 0.5mm2And is less than or equal to 3mm2。
In some embodiments, the micro-compressed sample is in a column shape, the cross section of the micro-compressed sample is in a square shape, the cross section is perpendicular to the height direction of the micro-compressed sample, the height of the micro-compressed sample is greater than 0.5mm and less than or equal to 3mm, the ratio of the height of the micro-compressed sample to the side length of the cross section is 1-3, and the area of the cross section is greater than 0.5mm2And is less than or equal to 3mm2。
In certain embodiments, the load of the compression test is less than or equal to 1000N and the load loading rate of the compression test is from 0.1 μm/s to 3 μm/s.
In certain embodiments, the step of determining the height and direction of the strategic locations of the metallic additive manufacturing form comprises:
determining a model key position of a geometric model of the metal additive manufacturing form in the geometric model; and
determining the height and the direction of the key position at the metal additive manufacturing forming piece according to the key position of the model and the position relation of the metal additive manufacturing forming piece and the geometric model.
In some embodiments, after the step of obtaining the micro-compression sample from the key location, the method for evaluating the local mechanical property of the metal additive manufacturing form comprises:
processing the minute compressed sample to make the surface of the minute compressed sample smooth and measuring the size of the processed minute compressed sample.
In some embodiments, the step of modifying the force-displacement curve and converting the modified force-displacement curve into a stress-strain curve of the micro-compressed sample comprises:
and correcting the force-displacement curve, and determining the stress-strain curve of the micro compression sample according to the corrected force-displacement curve and the size of the processed micro compression sample.
In certain embodiments, the step of modifying the force-displacement curve comprises:
obtaining the measurement displacement of the tiny compressed sample;
determining the actual displacement of the tiny compressed sample according to the preset model, wherein the preset model comprises the measured displacement; and
and correcting the force-displacement curve according to the actual displacement.
In some embodiments, the preset model is represented as:
wherein d issFor said actual displacement, dfFor said measurement of displacement, CiAnd F is a pressure value corresponding to the measurement displacement, and the measurement displacement and the pressure value are determined according to an output signal of the compression test testing machine.
In certain embodiments, the step of determining the elastic modulus and yield strength of the mechanical properties of the micro-compression sample from the stress-strain curve comprises:
and performing curve fitting in the elastic stage of the stress-strain curve so as to calculate the elastic modulus of the tiny compression sample, and determining the yield strength of the tiny compression sample according to the elastic modulus and the stress-strain curve.
Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a flow chart showing a method for evaluating local mechanical properties of a metal additive manufactured molded article according to an embodiment of the present invention;
FIG. 2 is a schematic perspective view of a metal additive manufacturing form according to an embodiment of the invention;
FIG. 3 is a schematic plan view of a metal additive manufacturing form according to an embodiment of the invention;
FIG. 4 is a schematic perspective view of a micro-compressed sample according to an embodiment of the present invention;
FIG. 5 is a perspective view of a micro-compressed sample according to another embodiment of the present invention;
fig. 6 is a schematic flow chart of a method for evaluating local mechanical properties of a metal additive manufactured molded article according to another embodiment of the present invention;
fig. 7 is a schematic flow chart of a method for evaluating local mechanical properties of a metal additive manufactured molded article according to still another embodiment of the present invention.
Description of the main element symbols:
the metal additive manufacturing part comprises a metal additive manufacturing part 10, a micro compression sample 12, a plane 14, the height H of a key position, a cross section S, a diameter d, the height H of the micro compression sample and a side length a.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.
Embodiments of the present invention provide a method for evaluating local mechanical properties of a metal additive manufactured part 10.
Referring to fig. 1, fig. 2 and fig. 3, a method for evaluating local mechanical properties of a metal additive manufactured part 10 according to an embodiment of the present invention includes the steps of:
s12: determining the height and direction of strategic locations of the metal additive manufacturing form 10;
s14: obtaining a tiny compressed sample 12 from a key position;
s16: performing a compression test on the micro-compressed sample 12 to obtain a force-displacement curve of the micro-compressed sample 12;
s18: correcting the force-displacement curve and converting the corrected force-displacement curve into a stress-strain curve of the micro compression sample 12; and
s20: and determining the mechanical properties of the micro compression sample 12 according to the stress-strain curve, wherein the mechanical properties comprise elastic modulus and yield strength.
According to the method for evaluating the local mechanical property of the metal additive manufacturing molded part 10, aiming at the characteristic that the structure and the mechanical property of the metal additive manufacturing molded part 10 are highly localized, the mechanical property of the key position of the metal additive manufacturing molded part 10 is represented by the tiny compression sample 12 obtained from the key position on the metal additive manufacturing molded part, and the problem that the standard sample cannot reflect the local property of the metal additive manufacturing molded part 10 is solved. The selected dimension of the micro compressed sample 12 not only has representativeness of macroscopic mechanical property, but also can accurately reflect the micro-area mechanical property of the designated height and the designated direction.
Specifically, the method for evaluating local mechanical properties of the metal additive manufactured molded article 10 according to the embodiment of the present invention is particularly suitable for an additive manufactured molded article and a material or member having uneven mechanical properties, such as a functionally graded material and an anisotropic material.
Note that, in step S20, the mechanical properties include not only the elastic modulus and the yield strength, but also other indexes, and the elastic modulus and the yield strength are merely used as examples of the mechanical properties and are not limited.
In steps S12 and S14, in the example of fig. 2 and 3, an XYZ coordinate system as shown in the figure can be established taking as an example the directions of the additively manufactured (selectively laser melted) shaped sample, i.e. the length direction, width direction and height direction of the metal additively manufactured shaped piece 10.
The direction of the X axis of the coordinate system is consistent with the width direction of the metal additive manufactured part 10, the direction of the Y axis of the coordinate system is consistent with the length direction of the metal additive manufactured part 10, and the direction of the Z axis of the coordinate system is consistent with the height direction of the metal additive manufactured part 10.
The metal additive manufactured piece 10 is rectangular in cross-section with dimensions 10mm by 25mm and a print height of 50 mm. Specifically, in step S14, 4 minute compression samples may be cut from the plane 14 having a distance H of 40mm from the bottom 16 of the metal additive manufactured piece 10 in the Z-axis direction: 12a, 12b, 12c, 12 d.
Referring to fig. 3, the axis of the minute compressed sample 12a is parallel to the Y axis, the axis of the minute compressed sample 12b is parallel to the X axis, the axis of the minute compressed sample 12c is parallel to the Z axis, and the axis of the minute compressed sample 12d forms an angle of 62 ° with the Y axis.
That is, the metal additive manufacturing shaped piece 10 is a rectangular parallelepiped having a length, a width, and a height of 25mm, 10mm, and 50mm, respectively. This example identifies four critical locations in the metal additive manufactured part 10, the first critical location having a height H of 40mm and oriented parallel to the Y-axis, from which a tiny compressed sample 12a is cut; the height H of the second key position is 40mm, the direction is parallel to the X axis, and a tiny compression sample 12b is cut from the second key position; the height H of the third key position is 40mm, the direction is parallel to the Z axis, and a tiny compressed sample 12c is cut from the third key position; the height H of the fourth key location was 40mm and the direction was 62 ° from the Y axis, and a small compressed sample 12d was cut from the fourth key location.
Referring to fig. 4, in some embodiments, the micro-compressed sample 12 is in a column shape, the cross section S of the micro-compressed sample 12 is in a circle shape, the cross section S is perpendicular to the height direction of the micro-compressed sample 12, and the height h of the micro-compressed sample 12 is larger than that of the micro-compressed sample 12At 0.5mm to 3mm, the ratio of the height h of the minute compressed sample 12 to the diameter d of the cross section S is 1 to 3, and the area of the cross section S is more than 0.5mm2And is less than or equal to 3mm2。
That is, the minute compressed sample 12 according to the embodiment of the present invention has a cylindrical shape, and the size of the minute compressed sample 12 is required to satisfy the range of the height h in (0.5, 3), the range of the ratio of the height h to the diameter d in [1,3], and the range of the area of the cross section S in (0.5, 3).
In one example, the height h of the minute compressed sample 12 is 1mm, the ratio of the height h to the diameter d of the minute compressed sample 12 is 1, and the area of the cross section S is 0.785mm2(ii) a In another example, the height h of the minute compressed sample 12 is 1mm, the ratio of the height h to the diameter d of the minute compressed sample 12 is 1.2, and the area of the cross section S is 0.56mm2(ii) a In yet another example, the height h of the minute compressed sample 12 is 3mm, the ratio of the height h to the diameter d of the minute compressed sample 12 is 3, and the area of the cross section S is 0.785mm2。
Referring to fig. 5, in some embodiments, the micro-compressed sample 12 is in a column shape, the cross section S of the micro-compressed sample 12 is in a square shape, the cross section S is perpendicular to the height direction of the micro-compressed sample 12, the height h of the micro-compressed sample 12 is greater than 0.5mm and less than or equal to 3mm, the height h of the micro-compressed sample 12 is less than or equal to 3mm, the ratio of the height h of the micro-compressed sample 12 to the side length a of the cross section S is 1 to 3, and the area of the cross section S is greater than 0.5mm2And is less than or equal to 3mm2. In this way, the micro-compressed sample 12 can accurately reflect the micro-area mechanical properties of the designated height and the designated direction, and at the same time, can have the representativeness of the macro-mechanical properties.
That is, the minute compressed sample 12 according to the embodiment of the present invention has a prism shape, and further, the minute compressed sample 12 according to the embodiment of the present invention has a rectangular parallelepiped shape. The dimensions of the micro-compressed sample 12 are such that the height h is (0.5, 3)]In a range of [1,3] the ratio of the height h to the side length a]In the range of (0.5, 3) the area of the cross section S]The range of (1). In one example, the height h of the minute compressed sample 12 is 1mm, and the height h and the side of the minute compressed sample 12The ratio of the length a is 1 and the area of the cross section S is 1mm2(ii) a In another example, the height h of the minute compressed sample 12 is 1mm, the ratio of the height h to the side length a of the minute compressed sample 12 is 1.2, and the area of the cross section S is 0.69mm2(ii) a In still another example, the height h of the minute compressed sample 12 is 3mm, the ratio of the height h to the side length a of the minute compressed sample 12 is 3, and the area of the cross section S is 1mm2。
Of course, the cross section S of the micro-compressed sample 12 may be a polygon such as a triangle, a pentagon, or other irregular shape as long as the cross section S of the micro-compressed sample 12 is uniform in the height direction, that is, as long as the micro-compressed sample 12 has a straight column shape.
In the example of fig. 2 and 3, the 4 minute compressed samples 12 are each cylindrical and uniform in size. Specifically, the height h of the minute compression sample 12 was 1mm, the diameter d was 1mm, and the area of the cross section S was 0.785mm2The ratio of the height h to the diameter d of the slightly compressed sample 12 was 2.
In certain embodiments, the load for the compression test is less than or equal to 1000N and the load rate for the compression test is from 0.1 μm/s to 3 μm/s. In this way, a compression test is achieved. Specifically, the micro-compression sample 12 may be placed in a mechanical property testing machine, and after parameters such as load and loading rate of the compression test are set, the testing machine may be started. Preferably, the load loading rate for the compression test is 1 μm/s.
In one example, the load for the compression test is 1000N and the loading rate is 0.5 μm/s; in another example, the load for the compression test is 800N and the loading rate is 1.5 μm/s; in yet another example, the load for the compression test is 500N and the loading rate is 1.0 μm/s.
In the example of fig. 2 and 3, the indenter depression distance of the tester is 0.3mm, the loading rate is 0.001mm/s, i.e. 1 μm/s, and the maximum force is 100N.
Note that 1000N is determined by the device, and the maximum capability of the device is 1000N. The load rate is the ratio of the distance depressed to the time to complete the depression distance. For example, if the pressing distance is 1mm and the pressing is completed within 1s, the loading rate is 1 mm/s; if completed within 10 seconds, the loading rate at this time was 0.1 mm/s. In this example, the pressing distance was 0.3mm, and the loading rate was 0.001mm/s, that is, the time for completing the pressing down by 0.3mm was 300 s.
In this manner, the force-displacement curves of the 4 minute compression samples 12 recorded by the testing machine can be obtained.
Referring to fig. 6, in some embodiments, step S12 includes:
step S122: determining a model key position of a geometric model in the geometric model of the metal additive manufactured piece 10; and
step S124: and determining the height and the direction of the key position in the metal additive manufacturing-shaped piece 10 according to the key position of the model and the position relation of the metal additive manufacturing-shaped piece 10 and the geometric model.
As such, the height and direction of the strategic locations of the metallic additive manufactured form 10 may be determined by a geometric model of the metallic additive manufactured form 10. Specifically, coordinates may be established in a geometric model of the metal additive manufactured form 10 and the height of the critical locations of the model and the direction in the plane of the height locations may be determined in the geometric model. Note that the coordinates coincide with coordinates in the manufacturing process of the metal additive manufacturing molded article 10, and the metal additive manufacturing molded article 10 coincides with the placement orientation of the geometric model.
Referring to fig. 7, in some embodiments, after step S14, the method for evaluating the local mechanical property of the metal additive manufactured part 10 includes:
step S15: the minute compressed sample 12 is processed to smooth the surface of the minute compressed sample 12 and the size of the processed minute compressed sample 12 is measured.
In this way, the measurement of the size of the minute compressed sample 12 is made more accurate. Specifically, after the minute compressed sample 12 is ground and polished so that the surface of the minute compressed sample 12 is smooth and free from burrs, the minute compressed sample 12 may be subjected to photographing measurement using a metallographic microscope, and then the size of the minute compressed sample 12 may be measured. Note that the "size of the minute compressed sample 12" herein refers to the height h of the minute compressed sample and the diameter d (or side length a) of the cross section S. It will be appreciated that the measured dimensions may satisfy the dimensional range of the micro-compressed sample 12 as previously described.
In certain embodiments, step S18 includes:
the force-displacement curve is corrected and the stress-strain curve of the minute compression sample 12 is determined based on the corrected force-displacement curve and the size of the processed minute compression sample 12.
Thus, the stress-strain curve is more accurate. It will be appreciated that the force-displacement curve recorded by the tester is the displacement of the indenter of the tester and not the actual displacement of the slightly compressed sample 12, so a correction to the force-displacement curve is required.
In some embodiments, the step of modifying the force-displacement curve comprises:
obtaining the measurement displacement of the micro compressed sample 12;
determining the actual displacement of the tiny compressed sample 12 according to a preset model, wherein the preset model comprises the measured displacement; and
and correcting the force-displacement curve according to the actual displacement.
In this way, a correction of the force-displacement curve is achieved. As mentioned above, the force-displacement curve recorded by the testing machine is not the actual displacement of the slightly compressed sample 12, that is, there is a certain deviation between the measured displacement recorded by the testing machine and the actual displacement of the slightly compressed sample 12. Therefore, the measured displacement recorded by the testing machine can be substituted into the preset model for calculation to reduce or even eliminate the deviation, so as to obtain the actual displacement of the tiny compression sample 12, and thus, the force-displacement curve can be corrected according to the actual displacement.
In some embodiments, the predetermined model is represented as:
wherein d issFor actual displacement, dfFor measuring displacement, CiCompliance of the individual parts of the test machine for compression tests, F is a measureAnd measuring the pressure value corresponding to the displacement, and determining the displacement and the pressure value according to the output signal of the testing machine of the compression test.
Thus, the force-displacement curve can be corrected according to the preset model. As can be appreciated, the first and second,
is the deviation between the measured displacement and the actual displacement. Since the deviation between the measured displacement and the actual displacement is generally caused by the testing machine, in order to obtain an accurate actual displacement of the minute compressed sample 12, it is necessary to measure the flexibility of each component of the testing machine such as the plunger and the sensor and to correct the measured flexibility by using a preset model. In the examples of FIGS. 2 and 3, the compliance of the test machine was measured to be 0.00118 mm/N.
In certain embodiments, step S20 includes:
curve fitting is performed at the elastic stage of the stress-strain curve to calculate the elastic modulus of the minute compression sample 12, and the yield strength of the minute compression sample 12 is determined from the elastic modulus and the stress-strain curve.
In this way, the elastic modulus and yield strength that determine the mechanical properties of the micro-compressed sample 12 are achieved.
In the example of fig. 2 and 3, the mechanical properties determined by the stress-strain curve of the minute compression specimen 12a may reflect the mechanical properties of the metal additive manufactured piece 10 at the plane 14 and in the Y-axis direction;
the mechanical property determined by the stress-strain curve of the micro compression sample 12b can reflect the mechanical property of the metal additive manufacturing-made piece 10 at the plane 14 and in the X-axis direction;
the mechanical property determined by the stress-strain curve of the tiny compression sample 12c can reflect the mechanical property of the metal additive manufacturing-made piece 10 at the plane 14 and in the Z-axis direction;
the mechanical properties determined from the stress-strain curve of the micro-compression sample 12d may reflect the mechanical properties of the metal additive manufactured part 10 at the plane 14 and in the direction of the 62 ° angle to the Y-axis.
It should be noted that the embodiments of the present invention may satisfy only one of the above embodiments or a plurality of the above embodiments at the same time, that is, an embodiment in which one or more of the above embodiments are combined also belongs to the scope of the embodiments of the present invention.
In the description of the specification, reference to the terms "some embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiments or examples is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are illustrative and not to be construed as limiting the present invention, and that variations, modifications, substitutions and alterations may be made in the above embodiments by those of ordinary skill in the art within the scope of the present invention, which is defined by the claims and their equivalents.
Claims (8)
1. A method for evaluating local mechanical properties of a metal additive manufacturing formed part is characterized by comprising the following steps of:
determining a height and a direction of a strategic location of the metal additive manufacturing form;
acquiring a tiny compressed sample from the key position;
performing a compression test on the micro-compressed sample to obtain a force-displacement curve of the micro-compressed sample;
correcting the force-displacement curve and converting the corrected force-displacement curve into a stress-strain curve of the micro compression sample; and
determining the mechanical properties of the micro compression sample according to the stress-strain curve, wherein the mechanical properties comprise elastic modulus and yield strength;
the step of modifying the force-displacement curve comprises the steps of:
obtaining the measurement displacement of the tiny compression sample;
determining the actual displacement of the tiny compressed sample according to a preset model, wherein the preset model comprises the measured displacement; and
correcting the force-displacement curve according to the actual displacement;
the preset model is expressed as:
wherein d issFor said actual displacement, dfFor said measurement of displacement, CiAnd F is a pressure value corresponding to the measurement displacement, and the measurement displacement and the pressure value are determined according to an output signal of the compression test testing machine.
2. The method for evaluating the local mechanical properties of the metal additive manufactured product according to claim 1, wherein the micro-compressed sample is columnar, the cross section of the micro-compressed sample is circular, the cross section is perpendicular to the height direction of the micro-compressed sample, the height of the micro-compressed sample is greater than 0.5mm and less than or equal to 3mm, the ratio of the height of the micro-compressed sample to the diameter of the cross section is 1-3, and the area of the cross section is greater than 0.5mm2And is less than or equal to 3mm2。
3. The method of evaluating the local mechanical properties of a metallic additive manufactured article according to claim 1, wherein the micro-compressed sample is columnar, the cross section of the micro-compressed sample is square, and the cross section is perpendicular to the height direction of the micro-compressed sampleThe height of the micro compressed sample is more than 0.5mm and less than or equal to 3mm, the ratio of the height of the micro compressed sample to the side length of the cross section is 1-3, and the area of the cross section is more than 0.5mm2And is less than or equal to 3mm2。
4. The method of evaluating localized mechanical properties of a metallic additive manufactured shape according to claim 1, wherein a load of the compression test is 1000N or less, and a load loading rate of the compression test is 0.1 μm/s to 3 μm/s.
5. The method of evaluating the local mechanical properties of a metallic additive manufactured form of claim 1, wherein the step of determining the height and direction of the strategic locations of the metallic additive manufactured form comprises:
determining a model key position of a geometric model of the metal additive manufacturing form in the geometric model;
determining the height and the direction of the key position at the metal additive manufacturing forming piece according to the key position of the model and the position relation of the metal additive manufacturing forming piece and the geometric model.
6. The method of evaluating the local mechanical properties of a metallic additive manufactured article according to claim 1, wherein after the step of obtaining the micro-compression sample from the critical location, the method of evaluating the local mechanical properties of a metallic additive manufactured article comprises the steps of:
processing the minute compressed sample to make the surface of the minute compressed sample smooth and measuring the size of the processed minute compressed sample.
7. The method of evaluating the local mechanical properties of a metallic additive manufactured shape according to claim 6, wherein the step of modifying the force-displacement curve and converting the modified force-displacement curve into a stress-strain curve of the micro-compression sample comprises:
and correcting the force-displacement curve, and determining the stress-strain curve of the micro compression sample according to the corrected force-displacement curve and the size of the processed micro compression sample.
8. The method of evaluating the local mechanical properties of a metallic additive manufactured shape according to claim 1, wherein the step of determining the elastic modulus and yield strength of the mechanical properties of the micro-compression sample from the stress-strain curve comprises:
and performing curve fitting in the elastic stage of the stress-strain curve so as to calculate the elastic modulus of the tiny compression sample, and determining the yield strength of the tiny compression sample according to the elastic modulus and the stress-strain curve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810929910.6A CN108982220B (en) | 2018-08-15 | 2018-08-15 | Method for evaluating local mechanical property of metal additive manufacturing formed part |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810929910.6A CN108982220B (en) | 2018-08-15 | 2018-08-15 | Method for evaluating local mechanical property of metal additive manufacturing formed part |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108982220A CN108982220A (en) | 2018-12-11 |
| CN108982220B true CN108982220B (en) | 2021-07-16 |
Family
ID=64553740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810929910.6A Active CN108982220B (en) | 2018-08-15 | 2018-08-15 | Method for evaluating local mechanical property of metal additive manufacturing formed part |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108982220B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110333137A (en) * | 2019-08-16 | 2019-10-15 | 西北工业大学 | A kind of thin-walled plate tube material compression performance test sample, fixture and method |
| CN110455624A (en) * | 2019-08-16 | 2019-11-15 | 华东理工大学 | A method of test metal material constitutive relation |
| CN112432852B (en) * | 2020-11-19 | 2022-11-22 | 中国医学科学院生物医学工程研究所 | Method for testing mechanical properties of 3D printing tissue engineering auricular cartilage and support |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102313677A (en) * | 2011-08-31 | 2012-01-11 | 湖南大学 | Detection method for identifying dynamic mechanical property parameter of different area materials in weld joint |
| CN103822874A (en) * | 2014-02-24 | 2014-05-28 | 山东大学 | Method for detecting residual stress in sheet based on crack flexibility |
| CN104596846A (en) * | 2014-12-25 | 2015-05-06 | 中国科学院力学研究所 | Method for correcting elasticity modulus and stress-strain curve in metal material compression test |
| KR20150091635A (en) * | 2014-02-03 | 2015-08-12 | 인하대학교 산학협력단 | Testing Method of Brittle Failure Potential of Rock Specimen |
| CN106872675A (en) * | 2015-12-14 | 2017-06-20 | 中航复合材料有限责任公司 | A kind of method for evaluating continuous fiber reinforced composite materials resin uniformity |
| CN107356479A (en) * | 2017-07-12 | 2017-11-17 | 南方科技大学 | Material during tensile method of evaluating performance based on selective laser melting process |
-
2018
- 2018-08-15 CN CN201810929910.6A patent/CN108982220B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102313677A (en) * | 2011-08-31 | 2012-01-11 | 湖南大学 | Detection method for identifying dynamic mechanical property parameter of different area materials in weld joint |
| KR20150091635A (en) * | 2014-02-03 | 2015-08-12 | 인하대학교 산학협력단 | Testing Method of Brittle Failure Potential of Rock Specimen |
| CN103822874A (en) * | 2014-02-24 | 2014-05-28 | 山东大学 | Method for detecting residual stress in sheet based on crack flexibility |
| CN104596846A (en) * | 2014-12-25 | 2015-05-06 | 中国科学院力学研究所 | Method for correcting elasticity modulus and stress-strain curve in metal material compression test |
| CN106872675A (en) * | 2015-12-14 | 2017-06-20 | 中航复合材料有限责任公司 | A kind of method for evaluating continuous fiber reinforced composite materials resin uniformity |
| CN107356479A (en) * | 2017-07-12 | 2017-11-17 | 南方科技大学 | Material during tensile method of evaluating performance based on selective laser melting process |
Non-Patent Citations (2)
| Title |
|---|
| Additive Design and Manufacturing of Jet Engine Parts;Pinlian Han;《Engineering》;20171231;第3卷(第5期);第648-652页 * |
| 改善金属增材制造材料组织与力学性能的方法与技术;袁丁 等;《航空制造技术》;20180620;第61卷(第10期);第40-46页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108982220A (en) | 2018-12-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108982220B (en) | Method for evaluating local mechanical property of metal additive manufacturing formed part | |
| US8501075B2 (en) | Method for manufacturing a three-dimensional object | |
| JP5435352B2 (en) | Method for determining the breaking strain of plate materials | |
| CN107356479B (en) | Metal material tensile property evaluation method based on selective laser melting technology | |
| US20190234908A1 (en) | Oscillation analysis on an object produced by means of additive manufacturing | |
| US20160282246A1 (en) | Method and Apparatus for Residual Stress Measurement Through Indentation with In-situ Generated Reference | |
| KR102047065B1 (en) | Estimation Apparatus and Method of Creep Crack Rate and Relevant Growth Fracture Parameters for Small Punch Specimen with a Micro Groove | |
| CN110366675B (en) | Apparatus and method for rapid screening of material properties in multiple additive manufacturing test samples | |
| Pellegrini et al. | Evaluation of anisotropic mechanical behaviour of 316L parts realized by metal fused filament fabrication using digital image correlation | |
| CN110333137A (en) | A kind of thin-walled plate tube material compression performance test sample, fixture and method | |
| Yasa et al. | Benchmarking of different powder-bed metal fusion processes for machine selection in additive manufacturing | |
| KR102095358B1 (en) | Apparatus for measuring thickness of battery materials | |
| JP2008175725A (en) | Poisson's ratio measuring method of thin-film-like material, and measuring device for it | |
| JP2008281390A (en) | Manufacturing method of bending test tool, bending test tool and bending test device | |
| EP3550280B1 (en) | Apparatus and method for evaluating electrode embrittlement | |
| US11060961B2 (en) | Apparatus and method for evaluating electrode embrittlement | |
| KR100965226B1 (en) | Evaluating method of the residual stress determining method using the continuous indentation method | |
| JP6288468B2 (en) | Forming limit test method and forming limit test apparatus for metal sheet | |
| CN111655461A (en) | Verification of additive manufacturing process | |
| Merkle et al. | Developing a model for the bond heel lifetime prediction of thick aluminium wire bonds | |
| Ahmed et al. | Investigation of the effect of three-point bending testing parameters on the behavior of 3D printed sand | |
| KR20100009758A (en) | Indentation-driven tensile test specimen with single test section and manufacturing method thereof | |
| KR20130077923A (en) | Calculation method for distribution of residual force | |
| Heerens et al. | Influence of specimen preparation, microstructure anisotropy, and residual stresses on stress–strain curves of rolled Al2024 T351 as derived from spherical indentation tests | |
| CN112432828B (en) | Method for measuring fracture limit strain of plane strain path of sheet metal material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20201009 Address after: 518000 303, room 5, Huiyuan, 1088, Xue Yuan Avenue, Taoyuan street, Nanshan District, Shenzhen, Guangdong. Applicant after: SHENZHEN YIDONG AVIATION TECHNOLOGY Co.,Ltd. Address before: 1088 No. 518055 Guangdong city of Shenzhen province Nanshan District Xili Xueyuan Road Applicant before: SOUTH University OF SCIENCE AND TECHNOLOGY OF CHINA |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |