Strengthening feeding method for ZL205A alloy casting

Abstract

The invention provides a reinforced feeding method for a ZL205A alloy casting. The method comprises the following steps: S1) inserting an ultrasonic vibration head into a casting mold riser; s2, the ZL205A alloy liquid is poured into a casting mold from a pouring gate opening, when the alloy liquid rises and makes contact with an ultrasonic vibration head, ultrasonic vibration is started, and the ultrasonic vibration head is taken out after ultrasonic vibration is finished; (S3) after the ZL205A alloy casting is completely solidified, a ZL205A casting blank is obtained; s4, the ZL205A casting blank is subjected to heat treatment, and the ZL205A alloy casting subjected to reinforced feeding is obtained.By means of the method, the feeding capacity of the ZL205A alloy casting can be effectively improved, the internal quality of the ZL205A alloy casting is improved, the body mechanical property of the ZL205A alloy casting is improved, and the design requirements for high performance and light weight of a material structure in the fields of aviation, aerospace, weapons and the like are better met.

Description

Technical Field

[0001] The invention belongs to the technical field of metal materials, and in particular relates to a method for strengthening and feeding shrinkage of a ZL205A alloy casting. Background Art

[0002] ZL205A alloy is one of the strongest cast aluminum alloys in the world so far. Based on its excellent mechanical properties, ZL205A alloy castings have been widely used as the main load-bearing structure in the fields of aviation, aerospace, weapons and other weapon equipment. ZL205A exhibits excellent comprehensive mechanical properties due to the aging strengthening characteristics of the Cu element and the combined effects of other auxiliary refinement and toughening elements. However, due to the solidification characteristics of the Al-Cu alloy itself, ZL205A alloy has a wide solid-liquid two-phase region during solidification (the temperature difference between the solid and liquid phases is up to 100°C), resulting in obvious mushy solidification during the solidification process of the alloy. When the alloy solidifies and shrinks, it is easy to produce insufficient shrinkage compensation and thus cause micro-porosity defects, which to a certain extent limits the improvement of the quality and performance of ZL205A castings and limits its large-scale promotion and application.

[0003] At present, there are two main measures to improve the shrinkage feeding capacity of ZL205A alloy. One is to increase the pouring temperature of the casting and improve the fluidity of the alloy itself, but it will also increase the solidification shrinkage rate of the alloy and cause problems such as alloy air absorption, which will cause other types of defects in the casting, such as segregation defects, bubbles and pinholes; the other is to strengthen the refinement of the alloy melt and improve the fluidity of the alloy itself, but the improvement effect is limited and cannot solve the problem of insufficient shrinkage feeding. Summary of the invention

[0004] In order to improve the problem of insufficient shrinkage feeding ability of existing ZL205A alloy castings during solidification, the present invention provides a method for strengthening shrinkage feeding of ZL205A alloy castings. The method can effectively improve the shrinkage feeding ability of ZL205A alloy castings, improve the internal quality of ZL205A alloy castings, avoid segregation defects, bubbles and pinholes in ZL205A alloy castings, improve the body mechanical properties of ZL205A alloy castings, and better meet the design requirements of aviation, aerospace, weapons and other fields for high-performance and lightweight material structures.

[0005] The object of the present invention is achieved through the following technical solutions: A method for strengthening shrinkage feeding of a ZL205A alloy casting, the method comprising the following steps: S1) inserting the ultrasonic vibration head into the riser of the casting mold; S2) ZL205A alloy liquid is poured into the casting mold from the runner. When the alloy liquid rises and contacts the ultrasonic vibration head, the ultrasonic vibration is turned on. After the ultrasonic vibration ends, the ultrasonic vibration head is taken out. S3) waiting for the ZL205A alloy casting to completely solidify, obtaining a ZL205A casting blank; S4) heat treating the ZL205A casting blank to obtain a ZL205A alloy casting with enhanced shrinkage compensation.

[0006] According to an embodiment of the present invention, in step S1), the insertion depth of the ultrasonic vibration head is 60-80% of the riser height of the mold, for example, 60%, 65%, 70%, 75% or 80%. When the insertion depth of the ultrasonic vibration head is 100% of the riser height of the mold, it means that the ultrasonic vibration head is inserted into the bottom of the riser of the mold; when the insertion depth of the ultrasonic vibration head is 0% of the riser height of the mold, it means that the ultrasonic vibration head is inserted into the top of the riser of the mold. When the insertion depth of the ultrasonic vibration head is 60-80% of the riser height, the alloy liquid in the solidification process can be effectively vibrated and crushed, the fluidity of the alloy liquid can be effectively improved, and the alloy liquid in the riser of the mold can be well compensated for the shrinkage of the alloy casting. When the insertion depth of the ultrasonic vibration head is 80-100% of the riser height, although the vibration crushing effect of the alloy liquid forming the casting body is enhanced, it also increases the risk of air entrainment generated to the casting body during ultrasonic vibration and when the ultrasonic vibration head is pulled out, so that the obtained alloy casting has defects such as bubbles and pinholes. When the insertion depth of the ultrasonic vibration head is 0-60% of the riser height, the vibration crushing effect on the alloy liquid forming the casting body is greatly weakened, and the alloy liquid in the riser of the casting cannot effectively compensate for the shrinkage of the alloy casting.

[0007] According to an embodiment of the present invention, in step S2), the time of the ultrasonic vibration is 5-8 minutes, for example, 5 minutes, 6 minutes, 7 minutes or 8 minutes; the power of the ultrasonic vibration is 1600-2000W, for example, 1600W, 1700W, 1800W, 1900W or 2000W.

[0008] According to an embodiment of the present invention, in step S2), the temperature of the ZL205A alloy liquid is controlled to be 650-680°C, and the alloy liquid is poured into the mold from the runner. When the alloy liquid rises and contacts the ultrasonic vibration head in the riser of the mold, the ultrasonic vibration is turned on, and the power of the ultrasonic vibration is controlled to be 1600-2000W. After 5-8 minutes of ultrasonic vibration, the ultrasonic vibration head is taken out.

[0009] According to the embodiments of the present invention, the traditional ultrasonic vibration treatment is mainly used in semi-continuous casting or continuous casting scenarios, specifically, the ultrasonic vibration treatment of the crystallizer in the casting process, and the ultrasonic vibration treatment at this time can affect the morphology and grain size of the precipitated phase when the alloy liquid solidifies, and is used to prepare deformed aluminum alloy bars or flat ingots. The inventor of the present application found through research that when the alloy liquid in the crucible is subjected to ultrasonic vibration treatment, the alloy liquid is poured into the casting mold after the treatment is completed; although the ultrasonic vibration treatment method can reduce bubbles and oxide inclusions in the melt to a certain extent, which is beneficial to improve the shrinkage compensation ability of ZL205A alloy castings, its shrinkage compensation effect is far inferior to the embodiments of the present invention, and the effect of improving the mechanical properties of the castings is not obvious.

[0010] The present invention is directed to a casting process for casting aluminum alloys. The present invention directly performs ultrasonic vibration treatment on the alloy liquid in the mold riser, which is a vibration crushing behavior implemented during the solidification process of the alloy liquid. The vibration crushing effect is more direct and more effective, and the crushing effect is stable and maintained for a longer time. Specifically, the present invention performs ultrasonic vibration treatment on the alloy liquid at the mold riser, and cavitation bubbles collapse and shatter during ultrasonic vibration, generating a large amount of strong impact energy, which can effectively crush the primary α (Al) crystal nuclei and eutectic Al-Cu structures formed during the solidification process of the alloy liquid. On the one hand, during the ultrasonic vibration crushing process, a large number of tiny crystal nuclei are formed in the alloy liquid, the number of aluminum grain nuclei increases, the organization is effectively refined, the grain boundaries in the matrix increase, the grain boundary energy decreases, and the fluidity of the alloy is improved, which is conducive to the shrinkage compensation of the alloy liquid to the casting; at the same time, the eutectic Al-Cu phase is finer and the shrinkage compensation channel is smoother; on the other hand, the ultrasonic vibration continuously crushes the eutectic Al-Cu phase precipitated during the solidification process, which can effectively inhibit the formation of a three-dimensional eutectic skeleton, delay the time of clogging of the alloy liquid shrinkage compensation channel, and further improve the shrinkage compensation capacity of the alloy liquid at the mold riser. In addition, the vibration wave at the mold riser is continuously transmitted to the casting body, which is conducive to the grain refinement and eutectic phase crushing of the casting body, and is more conducive to the improvement of the performance of the casting body.

[0011] According to an embodiment of the present invention, the method comprises the following steps: S0) A heat insulation layer is provided on the inner side of the riser of the ZL205A alloy casting.

[0012] According to an embodiment of the present invention, in step S0), the thermal insulation layer includes a carbon black layer, a rubber layer and a fiber layer which are arranged adjacent to each other in sequence, and the carbon black layer is arranged on a side close to the inner wall of the mold riser, and the fiber layer is arranged on a side away from the inner wall of the mold riser.

[0013] According to an embodiment of the present invention, the material of the carbon black layer is carbon black; the carbon black is derived from carbonization of an organic carbon source; illustratively, the carbon black layer is obtained by burning liquid acetylene.

[0014] According to an embodiment of the present invention, the thickness of the carbon black layer is 0.2-2 mm, for example, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm; the setting of the carbon black layer can play a heat insulating role, effectively slowing down the solidification rate of the alloy liquid at the riser of the casting, and achieving the effect of strengthening shrinkage compensation.

[0015] According to an embodiment of the present invention, the adhesive layer is made of a high temperature resistant adhesive, preferably an adhesive with a heat resistance temperature of not less than 170° C. The selection of the high temperature resistant adhesive can effectively prevent the fiber layer from debonding and falling off due to high temperature, and can also play a certain role in heat insulation.

[0016] According to an embodiment of the present invention, the thickness of the adhesive layer is 0.2-2 mm, for example, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm.

[0017] According to an embodiment of the present invention, the fiber layer is made of an aluminum silicate fiber layer or an aluminum oxide fiber layer.

[0018] According to an embodiment of the present invention, the fiber layer has a thickness of 1-10 mm, for example, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

[0019] According to an embodiment of the present invention, the number of the fiber layers is not particularly limited, and can be one layer or multiple layers. If there are multiple fiber layers, two adjacent fiber layers are connected by a glue layer.

[0020] According to an embodiment of the present invention, in step S0), the thickness of the thermal insulation layer is 5-20 mm, for example, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm or 20 mm.

[0021] According to an embodiment of the present invention, step S0) specifically includes the following steps: S01) Liquid acetylene is burned inside the riser of the ZL205A alloy casting to form a carbon black layer on the inner surface of the riser; S02) cutting the fiber layer according to the outline size of the riser of the ZL205A alloy casting; S03) Use adhesive to fix the fiber layer to the inner side of the casting riser with the carbon black layer, and cure it at room temperature for 20 to 30 minutes.

[0022] According to the implementation mode of the present invention, the inventor of the present application found through research that the thermal insulation risers currently supplied on the market are mostly made of materials such as bentonite, ceramics and rock wool. These thermal insulation risers have simple structures, mostly regular structures such as cylindrical, tubular and square, and are mainly used for rising pipe insulation and casting of simpler structures.

[0023] The present invention, on the other hand, sets a conformable heat-insulating layer on the inner side of the mold riser of the ZL205A alloy casting (the heat-insulating layer of the present invention can be set for mold risers of special-shaped structures or any size, unlike the heat-insulating risers on the market which are prefabricated with fixed shapes and sizes). The heat-insulating layer is a composite heat-insulating layer, which includes a carbon black layer, a glue layer and a fiber layer; the present invention first sets a carbon black layer on the inner surface of the mold riser by burning liquid acetylene; then selects a fiber layer of suitable material and cuts it into a suitable size, and then uses a high-temperature resistant adhesive to stick the fiber layer to the inner surface of the mold riser, forming a composite heat-insulating layer structure on the inner surface of the mold riser; the setting of the heat-insulating layer can achieve a better heat-insulating and heat-preserving effect. The setting of the thermal insulation layer is suitable for the risers of various small, medium and large-sized castings with special shapes and complex structures; further, the heat conduction rate of the alloy liquid to the riser of the casting can be adjusted by adjusting the thickness and number of the coated fiber layer to maintain the temperature of the alloy liquid at the riser of the casting. Compared with the traditional thermal insulation riser, the setting of the thermal insulation layer of the present invention can more effectively slow down the increase in the viscosity of the alloy liquid caused by the cooling of the alloy liquid at the riser of the casting, which is beneficial to the shrinkage compensation of the alloy liquid to the casting.

[0024] Furthermore, the present invention can also effectively adjust the shrinkage compensation strength of the aluminum alloy casting by setting insulation layers of different thicknesses on the mold risers at different positions of the casting, thereby achieving the purpose of adjusting the solidification sequence of different areas of the casting, realizing sequential solidification from top to bottom and from thin to thick, ensuring the performance improvement of key parts, and obtaining ZL205A alloy castings with better internal quality.

[0025] Beneficial effects of the present invention: The present invention provides a method for strengthening shrinkage feeding of a ZL205A alloy casting. The method can effectively improve the shrinkage feeding capacity of the ZL205A alloy casting, improve the internal quality of the ZL205A alloy casting, avoid the problems of segregation defects, bubbles and pinholes in the ZL205A alloy casting, improve the body mechanical properties of the ZL205A alloy casting, and better meet the design requirements of high-performance and lightweight material structures in the fields of aviation, aerospace, weapons, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : Microstructure comparison diagram of the ZL205A alloy casting of Comparative Example 2 and the ZL205A alloy casting of Example 2, Figure 1(a) represents Comparative Example 2, Figure 1 (b) in FIG. 2 represents Example 2.

[0027] Figure 2 : X-ray film of the ZL205A alloy casting of Example 2 (grade 1 porosity).

[0028] Figure 3 : X-ray film of the ZL205A alloy casting of Example 3 (grade 2 porosity).

[0029] Figure 4 : X-ray film of the ZL205A alloy casting of Comparative Example 2 (level 4 porosity).

[0030] Figure 5 : Actual picture of the mold riser of ZL205A alloy casting (the white one is the installed thermal insulation layer).

[0031] Figure 6 : A schematic structural diagram of a heat-insulating layer according to a preferred embodiment of the present invention; Figure numerals: 1 is the sand mold at the riser of the casting mold, 2 is the carbon black layer, 3 is the glue layer, and 4 is the fiber layer. DETAILED DESCRIPTION

[0032] The present invention will be described in further detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0033] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels.

[0034] Example 1 S1. Forming a carbon black layer with a thickness of 1 mm on the inner surface of the mold riser by burning liquid acetylene near the inner surface of the mold riser; taking an aluminum silicate fiber felt with a thickness of 5 mm, and cutting the aluminum silicate fiber felt according to the outline size of the mold riser of the ZL205A alloy casting; S2. Apply a high temperature resistant adhesive (such as commercially available Loctite 620 high temperature adhesive) evenly on the back of the first layer of aluminum silicate fiber felt, and then stick the first layer of aluminum silicate fiber felt on the surface of the carbon black layer inside the mold riser; apply the adhesive repeatedly, stick the second layer of aluminum silicate fiber felt on the first layer of aluminum silicate fiber felt, and leave it at room temperature for 20 minutes; S3, insert the ultrasonic vibration head into the mold riser, and the insertion depth is 70% of the mold riser height; S4, controlling the temperature of ZL205A alloy liquid to 665°C, and pouring the alloy liquid into the casting mold through the runner; S5. When the alloy liquid contacts the ultrasonic vibration head, the ultrasonic equipment is turned on to perform ultrasonic vibration treatment on the alloy liquid, and the power of the ultrasonic vibration is 1800W; after the ultrasonic vibration for 5 minutes, the ultrasonic vibration head is taken out; S6. After the alloy liquid is completely solidified, the casting mold is removed to obtain a ZL205A casting blank; S7. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0035] Example 2 S1. Forming a carbon black layer with a thickness of 1 mm on the inner surface of the mold riser by burning liquid acetylene near the inner surface of the mold riser; taking an aluminum silicate fiber felt with a thickness of 10 mm, and cutting the aluminum silicate fiber felt according to the outline size of the mold riser of the ZL205A alloy casting; S2. Apply a high temperature resistant adhesive (such as commercially available Loctite EA 9492 epoxy resin adhesive) evenly on the back of the aluminum silicate fiber felt, and then stick the aluminum silicate fiber felt on the surface of the carbon black layer on the inner side of the mold riser, and leave it at room temperature for 30 minutes; S3, insert the ultrasonic vibration head into the riser of the casting mold, and the insertion depth is 80% of the riser height; S4, controlling the temperature of ZL205A alloy liquid to 670°C, and pouring the alloy liquid into the casting mold through the runner; S5. When the alloy liquid contacts the ultrasonic vibration head, the ultrasonic equipment is turned on to perform ultrasonic vibration treatment on the alloy liquid, and the power of the ultrasonic vibration is 2000W; after the ultrasonic vibration for 6 minutes, the ultrasonic vibration head is taken out; S6. After the alloy liquid is completely solidified, the casting mold is removed to obtain a ZL205A casting blank; S7. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0036] Example 3 S1. Insert the ultrasonic vibration head into the riser of the casting mold, and the insertion depth is 80% of the riser height; S2, controlling the temperature of ZL205A alloy liquid to 670°C, and pouring the alloy liquid into the casting mold through the runner; S3. When the alloy liquid contacts the ultrasonic vibration head, the ultrasonic equipment is turned on to perform ultrasonic vibration treatment on the alloy liquid, and the power of the ultrasonic vibration is 2000W; after the ultrasonic vibration for 6 minutes, the ultrasonic vibration head is taken out; S4, after the alloy liquid is completely solidified, the casting mold is removed to obtain the ZL205A casting blank; S5. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0037] Comparative Example 1 S1. Forming a carbon black layer with a thickness of 1 mm on the inner surface of the mold riser by burning liquid acetylene near the inner surface of the mold riser; taking an aluminum silicate fiber felt with a thickness of 10 mm, and cutting the aluminum silicate fiber felt according to the outline size of the mold riser of the ZL205A alloy casting; S2. Apply a high temperature resistant adhesive (such as commercially available Loctite EA 9492 epoxy resin adhesive) evenly on the back of the aluminum silicate fiber felt, and then stick the aluminum silicate fiber felt on the surface of the carbon black layer on the inner side of the mold riser, and leave it at room temperature for 30 minutes; S3, controlling the temperature of ZL205A alloy liquid to 670°C, and pouring the alloy liquid into the casting mold through the runner; S4, after the alloy liquid is completely solidified, the casting mold is removed to obtain the ZL205A casting blank; S5. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0038] Comparative Example 2 S1. Control the temperature of ZL205A alloy liquid to 670°C and pour the alloy liquid into the casting mold through the runner; S2, after the alloy liquid is completely solidified, the casting mold is removed to obtain the ZL205A casting blank; S3. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0039] Comparative Example 3 S1. Forming a carbon black layer with a thickness of 1 mm on the inner surface of the mold riser by burning liquid acetylene near the inner surface of the mold riser; taking an aluminum silicate fiber felt with a thickness of 10 mm, and cutting the aluminum silicate fiber felt according to the outline size of the mold riser of the ZL205A alloy casting; S2. Apply a high temperature resistant adhesive (such as commercially available Loctite EA 9492 epoxy resin adhesive) evenly on the back of the aluminum silicate fiber felt, and then stick the aluminum silicate fiber felt on the surface of the carbon black layer on the inner side of the mold riser, and leave it at room temperature for 30 minutes; S3, controlling the temperature of the ZL205A alloy liquid to 670°C, subjecting the alloy liquid in the crucible to ultrasonic vibration treatment, the power of the ultrasonic vibration being 1800W, and after vibrating for 5 minutes, pouring the alloy liquid into the casting mold through the runner; S4, after the alloy liquid is completely solidified, the casting mold is removed to obtain the ZL205A casting blank; S5. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0040] Comparative Example 4 S1. Pre-embed a commercially available straight tube insulation sleeve with a thickness of 10 mm and a diameter of 100 mm (such as that sold by Changxing Dingfeng Company) into the riser of the casting sand mold; S2, control the temperature of ZL205A alloy liquid to 670℃, and pour the alloy liquid into the casting mold through the runner; S3, after the alloy liquid is completely solidified, the casting mold is removed to obtain the ZL205A casting blank; S4. The ZL205A casting blank is heat treated according to the ZL205A alloy T5 state heat treatment process specified in HB 962 to obtain a ZL205A alloy casting.

[0041] The internal quality and mechanical properties of the ZL205A alloy castings of the embodiments and comparative examples were tested. The ZL205A alloy castings were X-ray tested according to HB / Z60 "X-ray photography inspection", and the porosity level of the castings was determined according to HB 6578 "Aluminum alloy castings". The mechanical properties of the test bars cut from the same position of the ZL205A alloy castings were tested according to GB / T 228.1 "Tensile testing of metallic materials Part 1: Room temperature test methods", and the test results are shown in Table 1.

[0042] Table 1 Internal quality and mechanical properties test results of ZL205A alloy castings of the embodiment and comparative example

[0043] From the comparison of Comparative Examples 1-2 and Examples 1-3, it can be seen that both ultrasonic vibration and thermal insulation layer can play a significant role in alloy shrinkage compensation and performance improvement. The ZL205A alloy casting obtained after applying ultrasonic vibration alone has a tendency to loosen, but can reach a loose grade of level 2 (Example 3); the ZL205A alloy casting obtained after setting a thermal insulation layer alone also has a tendency to loosen, which can reach a loose grade of level 3 (Comparative Example 1); the ZL205A alloy casting obtained after applying ultrasonic vibration and setting a thermal insulation layer at the same time has the smallest loosening tendency, which can reach a loose grade of ≤level 1, and the internal quality and mechanical properties of the obtained ZL205A alloy casting are the best (Examples 1 and 2); when no thermal insulation layer is set and no ultrasonic vibration is applied, that is, when manufactured according to the traditional process, the looseness of the ZL205A alloy casting can only meet the looseness requirements of level 4, and the strength and elongation are poor (Comparative Example 2). Moreover, it can be seen from the comparison between comparative examples 1-2 and embodiments 1-3 that the shrinkage compensation effect of ultrasonic vibration at the riser is better than that of the heat insulation layer. In general, the heat insulation layer and ultrasonic vibration combined with the riser of the casting implemented in the present invention have the best internal quality and mechanical properties of the casting.

[0044] From the comparison between Examples 1-2 and Comparative Example 3, it can be seen that when ultrasonic vibration is applied to the alloy liquid in the mold riser instead of the alloy liquid in the crucible, the internal quality looseness grade of the obtained ZL205A alloy casting is reduced from ≤1 looseness grade to 3 looseness grade, and the comprehensive mechanical properties are also significantly reduced compared with Examples 1-2. From the comparison between Comparative Example 1 and Comparative Example 3, it can be seen that the shrinkage feeding effect of the ZL205A alloy casting is not significant when ultrasonic vibration is applied to the alloy liquid in the crucible.

[0045] From the comparison between Comparative Example 1 and Comparative Example 4, it can be seen that when the size of the ZL205A alloy casting is large, it is difficult to purchase an insulation sleeve of the full-size sand mold riser size on the market, and only the insulation sleeve can be pre-embedded in the local sand mold. The internal quality of the obtained ZL205A alloy casting is uneven, with local level 3 looseness and local level 4 looseness, and the mechanical properties are also significantly reduced.

[0046] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for strengthening shrinkage feeding of ZL205A alloy castings, wherein: The method comprises the following steps: S1) inserting the ultrasonic vibration head into the riser of the casting mold; S2) ZL205A alloy liquid is poured into the casting mold from the runner. When the alloy liquid rises and contacts the ultrasonic vibration head, the ultrasonic vibration is turned on. After the ultrasonic vibration ends, the ultrasonic vibration head is taken out. S3) waiting for the ZL205A alloy casting to completely solidify, obtaining a ZL205A casting blank; S4) heat treating the ZL205A casting blank to obtain a ZL205A alloy casting with enhanced shrinkage compensation.

2. The reinforcing feeding method according to claim 1, wherein: In step S1), the insertion depth of the ultrasonic vibration head is 60-80% of the height of the mold riser.

3. The reinforcing feeding method according to claim 1, wherein: In step S2), the ultrasonic vibration time is 5-8 minutes; the ultrasonic vibration power is 1600-2000W.

4. The reinforcing feeding method according to claim 1, wherein: In step S2), the temperature of the ZL205A alloy liquid is controlled to be 650-680°C, and the alloy liquid is poured into the mold from the runner. When the alloy liquid rises and contacts the ultrasonic vibration head in the mold riser, the ultrasonic vibration is turned on, and the power of the ultrasonic vibration is controlled to be 1600-2000W. After the ultrasonic vibration is performed for 5-8 minutes, the ultrasonic vibration head is taken out.

5. The reinforcing feeding method according to any one of claims 1 to 4, wherein: The method comprises the following steps: S0) A heat insulation layer is provided on the inner side of the riser of the ZL205A alloy casting.

6. The reinforcing feeding method according to claim 5, wherein: In step S0), the heat insulation layer includes a carbon black layer, a rubber layer and a fiber layer which are arranged adjacent to each other in sequence, and the carbon black layer is arranged on a side close to the inner wall of the mold riser, and the fiber layer is arranged on a side away from the inner wall of the mold riser.

7. The reinforcing feeding method according to claim 6, wherein: The material of the carbon black layer is carbon black; And / or, the thickness of the carbon black layer is 0.2-2 mm; And / or, the thickness of the adhesive layer is 0.2-2 mm.

8. The reinforcing feeding method according to claim 6, wherein: The fiber layer is made of aluminum silicate fiber layer or aluminum oxide fiber layer; And / or, the fiber layer has a thickness of 1-10 mm.

9. The reinforcing feeding method according to claim 5, wherein: In step S0), the thickness of the thermal insulation layer is 5-20 mm.

10. The reinforcing feeding method according to claim 5, wherein: Step S0) includes the following steps: S01) Liquid acetylene is burned inside the riser of the ZL205A alloy casting to form a carbon black layer on the inner surface of the riser; S02) cutting the fiber layer according to the outline size of the riser of the ZL205A alloy casting; S03) Use adhesive to fix the fiber layer to the inner side of the casting riser with the carbon black layer, and cure it at room temperature for 20 to 30 minutes.

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