Additive manufacturing forming process detection method and aluminum alloy part

Abstract

The invention relates to an additive manufacturing forming process detection method and an aluminum alloy part, and belongs to the technical field of additive manufacturing. The detection method comprises the following steps: planning a part feature structure, forming a slice, and dividing the slice into a scanning entity and a scanning contour; powder bed fusion printing is carried out, radioactive element ions are injected according to the scanning path of the scanning contour, and the injection frequency is controlled; capturing and judging radioactive elements, and if the radioactive elements are continuously distributed, continuing printing; and if the radioactive elements are discontinuously or irregularly distributed, printing is paused. According to the detection method provided by the invention, the printed area can be accurately detected in real time, and a designer can make an accurate judgment.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to an additive manufacturing forming process detection method and an aluminum alloy part. Background Art

[0002] In the process of additive manufacturing, parts often crack, bulge, and warp. This is especially true in powder bed fusion technology. Due to the slow heat dissipation of the powder bed, stress accumulation and / or heat accumulation occur in the parts, causing cracks in the powder buried area (the area that has been printed).

[0003] At present, the only methods for monitoring cracking are melt pool monitoring and equipment equipped with cameras to take photos. The above methods can only monitor in real time, that is, monitor the current printing layer. Due to the gradual burial of powder materials, it is impossible to determine whether cracking occurs in the printed area and where cracking occurs.

[0004] This problem causes great trouble to the production process, affects the judgment of designers, and causes great economic losses due to the inability to assess the risk of cracking and timely stop. Therefore, a real-time monitoring method is urgently needed to detect the printed area. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide an additive manufacturing forming process detection method and an aluminum alloy part to solve the problem that the existing detection method cannot detect the printed area in real time.

[0006] In one aspect, the present invention provides a method for detecting an additive manufacturing forming process, comprising the following steps:

[0007] S1: Plan the feature structure of the part and form slices, dividing it into scanning entities and scanning contours;

[0008] S2: Powder bed fusion printing, injecting radioactive element ions according to the scanning path of the scanning profile, and controlling its injection frequency;

[0009] S3: Capture and judgement of radioactive elements. If the radioactive elements are distributed continuously, printing will continue; if the radioactive elements are distributed intermittently or irregularly, printing will be suspended.

[0010] Furthermore, the radioactive element is europium.

[0011] Furthermore, the frequency of injection of the radioactive element ions is once every 10 to 100 layers.

[0012] Furthermore, the implantation amount of the radioactive element ions is 5×10 15 -5×10 16 ions / cm2 .

[0013] Furthermore, the radioactive element ion implantation parameters are: acceleration voltage of 80-150 kV, beam intensity of 15-30 μA, and implantation angle of 45°-90°.

[0014] Furthermore, the part is made of aluminum alloy, and its chemical composition, measured by mass percentage, includes: Si: 9-10%, Mg: 0.2-0.5%, Fe: ≤0.5%, Cu: ≤0.05%; the balance is Al.

[0015] Furthermore, the powder bed melting is a laser selective melting process.

[0016] Furthermore, in the laser selective melting process: the scanning speed is 1100-1500 mm / s, the laser power is 350-500w, the scanning interval is 0.08-0.15mm, and the powder layer thickness is 0.03-0.06mm.

[0017] Furthermore, the implantation width of the radioactive element ions is 0.1-0.5 mm.

[0018] On the other hand, the present invention provides an aluminum alloy part formed by additive manufacturing, wherein the detection method of the present invention is used in the additive manufacturing, and the aluminum alloy part contains a radioactive element ion implantation layer.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] 1. The present invention divides the parts to be printed into scanning entities and scanning contours, injects radioactive elements and controls the injection frequency when printing the scanning contours; when cracks appear during the printing process, the radioactive elements are discontinuous, and printing needs to be stopped; when there are no cracks, the radioactive elements are continuous, and printing does not need to be stopped. The detection method provided by the present invention can detect the printed area in real time and accurately, and designers can make accurate judgments;

[0021] 2. The radioactive element in the present invention is europium, which can ensure that it can penetrate the aluminum alloy and clearly observe its distribution on the one hand, and does not affect or guarantee the performance of the aluminum alloy parts on the other hand; in addition, it is also necessary to strictly control the injection amount, injection frequency and injection parameters of the radioactive element to ensure its strength, injection depth and distribution uniformity, so that designers can make accurate judgments.

[0022] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0024] Figure 1 This is a picture of the parts cracking during the printing process;

[0025] Figure 2 Scanning physical roadmaps for printing;

[0026] Figure 3 Scanning contour roadmap for printing process;

[0027] Figure 4 It is a schematic diagram of the test results;

[0028] In the figure, 1, printing layer; 2, ion implantation layer. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0030] During the additive manufacturing process, stress accumulation or heat accumulation may cause cracking, bulging, and warping of parts (see Figure 1 ). Currently, the only methods for monitoring cracking are melt pool monitoring and equipment equipped with cameras to take pictures. The above methods can only monitor in real time, that is, monitor the current printing layer.

[0031] However, in the field of powder bed fusion technology, there is a gradual powder spreading process, and the powder in the unprinted area will cover the printed area. Therefore, the existing detection method cannot detect the cracking problem in the printed area, so it is impossible to make an accurate judgment.

[0032] Therefore, the present invention provides a method for detecting an additive manufacturing forming process, comprising the following steps:

[0033] S1: Plan the feature structure of the part and form slices, dividing it into scanning entities and scanning contours;

[0034] S2: Powder bed fusion printing, injecting radioactive element ions according to the scanning path of the scanning profile, and controlling its injection frequency;

[0035] S3: Capture and judgement of radioactive elements. If the radioactive elements are distributed continuously, printing will continue; if the radioactive elements are distributed intermittently or irregularly, printing will be suspended.

[0036] Compared with the prior art, the additive manufacturing forming process detection method provided by the present invention utilizes the addition of radioactive elements during printing, and finally captures the radioactive elements and determines whether the radioactive elements are distributed continuously.

[0037] It should be noted that in the additive manufacturing process and the testing process, the scanning path is first planned and sliced ​​according to the structural characteristics of the parts; then printing is performed. During the printing process, powder printing is performed layer by layer, first printing the scanning entity, then printing the scanning contour, and injecting radioactive element ions according to the scanning path of the scanning contour. When injecting radioactive element ions, it is not injected layer by layer, but different layers are required to be spaced apart; finally, the radioactive element ions are captured or detected. When there are no problems such as cracks, the radioactive elements are distributed continuously, but when there are problems such as cracks, the radioactive elements are distributed discontinuously.

[0038] The detection method provided by the present invention can be used for real-time detection during the printing process. When an intermittent state occurs, the printing is immediately suspended, and the designer determines whether printing can be performed or adjusts the corresponding printing parameters. The detection method provided by the present invention can also be used for detection after the printing is completed. Some parts crack during the cooling process, some on the surface and some inside. The present invention can still observe the distribution of radioactive element ions to determine the crack situation.

[0039] Specifically, the radioactive element is europium.

[0040] It should be noted that the radioactive element used in the present invention is europium. On the one hand, europium can penetrate aluminum alloy, making it easy to capture or observe its distribution; on the other hand, europium not only does not reduce the performance of aluminum alloy, but improves it.

[0041] After europium ions are injected into aluminum alloys, they interact with aluminum and other alloying elements to form some new compound phases or solid solution phases, such as Mg 2 Eu, EuSi 2The formation of these new phases can change the microstructure of the aluminum alloy surface, such as forming fine dispersed strengthening phases, thereby affecting the performance of the aluminum alloy. In addition, it helps to refine the grains on the surface of the aluminum alloy and reduce the grain size. Grain refinement can increase the grain boundary area, hinder dislocation movement, and thus improve the strength and hardness of the aluminum alloy surface. It may also improve its toughness and fatigue resistance, and further reduce the risk of cracking.

[0042] Specifically, the radioactive element ions are injected once every 10 to 100 layers.

[0043] It should be noted that when injecting radioactive element ions, the injection is not performed layer by layer, but at a certain interval, that is, the injection frequency. In the present invention, the injection frequency is controlled to be injected once every 10 to 100 layers, that is, one layer is injected every 10 to 100 layers of aluminum alloy. When the injection frequency is too fast, that is, less than 10 layers, the distance between the injected ion layers is close, there is mutual interference, and it is impossible to judge whether cracks occur; when the injection frequency is too slow, that is, more than 100 layers, the distance between the injected ion layers is far, and it is impossible to determine whether the aluminum alloy layer between the ion layers is cracked.

[0044] Preferably, the injection frequency of the radioactive element ions of the present invention can be 10 layers, 20 layers, 30 layers, 40 layers, 45 layers, 50 layers, 55 layers, 60 layers, 70 layers, 83 layers, 90 layers, 95 layers or 100 layers.

[0045] Preferably, the frequency of implantation of radioactive element ions in the present invention is 30-80 layers.

[0046] More preferably, the frequency of implantation of radioactive element ions in the present invention is 40-60 layers.

[0047] Specifically, the amount of radioactive element ions injected is 5×10 15 -5×10 16 ions / cm 2 .

[0048] It should be noted that the amount of ion injection is expressed in terms of the number of ions per square centimeter. The amount of injection directly affects the concentration and distribution of ions on the surface of the printed part, and thus determines its display intensity. 15 ions / cm 2 When the injection volume is higher than 5×10 16 ions / cm 2 It has little effect on the test results, but it will cause waste.

[0049] Specifically, the radioactive element ion implantation parameters are: acceleration voltage of 80-150 kV, beam intensity of 15-30 μA, and implantation angle of 45°-90°.

[0050] It should be noted that the present invention uses an existing ion implanter to stably implant the radioactive element europium onto the surface of the aluminum alloy (the printed part), and needs to control the acceleration voltage, beam intensity and implantation angle.

[0051] The magnitude of the accelerating voltage determines the implantation depth of the europium ions. When the accelerating voltage is less than 80 kV, the implantation depth is shallow. On the contrary, when the accelerating voltage is greater than 150 kV, the implantation depth is deep. In the present invention, the shallow or deep implantation depth of the ions is not conducive to the accurate judgment of the designer, so the accelerating voltage can be 80 kV, 85 kV, 90 kV, 95 kV, 100 kV, 110 kV, 120 kV, 130 kV, 1350 kV, 140 kV or 150 kV.

[0052] Preferably, the accelerating voltage is 100-120 kV.

[0053] The beam intensity determines the ion injection efficiency and needs to be controlled at 15-30μA. The greater the beam intensity, the more europium ions are injected into the printed area surface per unit time, and the higher the injection efficiency. However, it may also cause the surface temperature of the part to rise too quickly, resulting in thermal effects and affecting the quality and performance of the injection layer. On the contrary, the smaller the beam intensity, the fewer europium ions are injected into the printed area surface per unit time, and the lower the injection efficiency.

[0054] Preferably, the beam intensity may be 15 μA, 18 μA, 20 μA, 25 μA, 28 μA or 30 μA.

[0055] More preferably, the beam current intensity is 20-25 μA.

[0056] The control of the injection angle can ensure the uniformity of ion injection and the consistency of depth distribution. The present invention controls the injection angle to be 45-90°. The injection is performed perpendicular to the surface of the printed area, so that the ions can be incident vertically to ensure the uniformity of injection and the consistency of depth distribution. However, in some special cases, such as when it is necessary to optimize the performance in a specific direction, a certain angle of tilted injection can also be used, but the angle is generally not too large to avoid reflection and scattering of ions on the sample surface, which affects the injection effect.

[0057] Preferably, the injection angle is 60°-90°.

[0058] Specifically, the part is an aluminum alloy, and the chemical composition thereof includes, by mass percentage, Si: 9-10%, Mg: 0.2-0.5%, Fe: ≤0.5%, Cu: ≤0.05%; the balance is Al.

[0059] It should be noted that the material of the parts in the present invention is aluminum alloy. Through the mutual cooperation between the elements, on the one hand, the strength of the parts is guaranteed and cracking is reduced. On the other hand, the penetration of the radioactive element europium is guaranteed. Because the ions implanted are profile parameters, the scanning range of the profile parameters is only about 0.1mm, which has little impact on the product. Moreover, a small amount of europium forms Al with Al. 3 Eu second phase plays a strengthening role after heat treatment and enhances the surface strength of parts.

[0060] Specifically, the powder bed melting is a laser selective melting process.

[0061] Specifically, in the laser selective melting process: the scanning speed is 1100-1500 mm / s, the laser power is 350-500w, the scanning spacing is 0.08-0.15mm, and the powder layer thickness is 0.03-0.06mm.

[0062] Preferably, the scanning speed is 1200 mm / s, the laser power is 400 w, the scanning interval is 0.1 mm, and the powder layer thickness is 0.05 mm.

[0063] Specifically, the implantation width of the radioactive element ions is 0.1-0.5 mm.

[0064] The present invention provides an aluminum alloy part, which is formed by additive manufacturing, wherein the detection method of the present invention is used in the additive manufacturing, and the aluminum alloy part contains a radioactive element ion implantation layer. The part of the present invention can be designed according to actual needs, and its material is aluminum alloy, and Mg is formed in the aluminum alloy. 2 Eu or EuSi 2 Mutually.

[0065] In order to more clearly describe the present invention, it is further illustrated by the following examples and comparative examples.

[0066] Example 1

[0067] The detection during the printing process specifically includes the following steps:

[0068] S1: Plan the feature structure of the part and form slices, dividing it into scanning entities and scanning contours (refer to Figure 2 and Figure 3 );

[0069] S2: Powder bed fusion printing, and injecting radioactive element ions to control their injection frequency according to the scanning path of the scanning profile;

[0070] The material of the parts is aluminum alloy, and the chemical composition, calculated by mass percentage, includes: Si: 9.5%, Mg: 0.3%, Fe: 0.2%, Cu: 0.05%; the balance is Al.

[0071] Powder bed fusion printing uses laser selective melting process, with a scanning speed of 1200mm / s, a laser power of 400w, a scanning spacing of 0.1mm, and a powder layer thickness of 0.05mm;

[0072] Radioactive element ions europium are injected, and the amount of radioactive element ions injected is 5×1015ions / cm 2 , the acceleration voltage is 100 kV, the beam intensity is 20 μA, the injection angle is 90° (vertical to the printed area); and the injection frequency is once for every 10 layers; the injection width of the radioactive element ions is 0.1 mm.

[0073] S3: Capture and judgement of radioactive elements. If the radioactive elements are distributed continuously, printing will continue; if the radioactive elements are distributed intermittently or irregularly, printing will be suspended.

[0074] Example 2

[0075] The inspection of the final product after printing includes the following steps:

[0076] S1: Plan the feature structure of the part and form slices; divide it into scanning entity and scanning contour;

[0077] S2: Powder bed fusion printing, and injecting radioactive element ions to control their injection frequency according to the scanning path of the scanning profile;

[0078] The material of the parts is aluminum alloy, and the chemical composition includes, by mass percentage, Si: 10.0%, Mg: 0.5%, Fe: 0.25%, Cu: 0.01%; the balance is Al.

[0079] Powder bed fusion printing uses laser selective melting process, with a scanning speed of 1100mm / s, a laser power of 350w, a scanning spacing of 0.08mm, and a powder layer thickness of 0.03mm;

[0080] The radioactive element ion europium is injected, and the injection amount of the radioactive element ion is 5×10 16 ions / cm 2 , the acceleration voltage is 150 kV, the beam intensity is 30 μA, the injection angle is 80°, and the injection frequency is once every 50 layers.

[0081] S3: Capture and judgment of radioactive elements. If the radioactive elements are distributed continuously, there are no cracks; if the radioactive elements are distributed intermittently or irregularly, there are cracks.

[0082] Example 3

[0083] The detection during the printing process specifically includes the following steps:

[0084] S1: Plan the feature structure of the part and form slices; divide it into scanning entity and scanning contour;

[0085] S2: Powder bed fusion printing, and injecting radioactive element ions to control their injection frequency according to the scanning path of the scanning profile;

[0086] The material of the parts is aluminum alloy, and the chemical composition includes, by mass percentage, Si: 10.0%, Mg: 0.5%, Fe: 0.25%, Cu: 0.01%; the balance is Al.

[0087] Powder bed fusion printing uses a laser selective melting process with a scanning speed of 1500mm / s, a laser power of 500w, a scanning spacing of 0.15mm, and a powder layer thickness of 0.06mm.

[0088] The radioactive element ion europium is injected, and the injection amount of the radioactive element ion is 5×10 16 ions / cm 2 , the acceleration voltage is 80 kV, the beam intensity is 15 μA, the injection angle is 80°, and the injection frequency is once every 90 layers.

[0089] S3: Capture and judgment of radioactive elements. If the radioactive elements are distributed continuously, there are no cracks; if the radioactive elements are distributed intermittently or irregularly, there are cracks.

[0090] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for detecting an additive manufacturing forming process, characterized in that: The following steps are involved: S1: Plan the feature structure of the part and form slices, dividing it into scanning entities and scanning contours; S2: Powder bed fusion printing, injecting radioactive element ions according to the scanning path of the scanning profile, and controlling its injection frequency; S3: Capture and judgement of radioactive elements. If the radioactive elements are distributed continuously, printing will continue; if the radioactive elements are distributed intermittently or irregularly, printing will be suspended.

2. The additive manufacturing forming process detection method according to claim 1, characterized in that: The radioactive element is europium.

3. The additive manufacturing forming process detection method according to claim 1, characterized in that: The radioactive element ions are injected once every 10 to 100 layers.

4. The additive manufacturing forming process detection method according to claim 1, characterized in that: The amount of radioactive element ions injected is 5×10 15 -5×10 16 ions / cm 2 .

5. The additive manufacturing forming process detection method according to claim 1, characterized in that: The radioactive element ion implantation parameters are as follows: acceleration voltage is 80-150 kV, beam intensity is 15-30 μA, and implantation angle is 45°-90°.

6. The additive manufacturing forming process detection method according to claim 1, characterized in that: The part is made of aluminum alloy, and the chemical composition thereof includes, by mass percentage, Si: 9-10%, Mg: 0.2-0.5%, Fe: ≤0.5%, Cu: ≤0.05%; the balance is Al.

7. The additive manufacturing forming process detection method according to claim 1, characterized in that: The powder bed melting is a laser selective melting process.

8. The additive manufacturing forming process detection method according to claim 7, characterized in that: In the laser selective melting process, the scanning speed is 1100-1500 mm / s, the laser power is 350-500 w, the scanning interval is 0.08-0.15 mm, and the powder layer thickness is 0.03-0.06 mm.

9. The additive manufacturing forming process detection method according to claim 1, characterized in that: The implantation width of the radioactive element ions is 0.1-0.5 mm.

10. An aluminum alloy part, characterized in that: The aluminum alloy part is formed by additive manufacturing, wherein the detection method according to any one of claims 1 to 9 is used in the additive manufacturing, and the aluminum alloy part contains a radioactive element ion implantation layer.

Images