Preparation method and application of investment casting wax

Abstract

The invention discloses a preparation method and application of investment casting wax. The investment casting wax is prepared from the following raw materials in parts by mass: 15 to 25 parts of paraffin, 10 to 20 parts of lignite wax, 15 to 20 parts of C5 petroleum resin, 2 to 10 parts of beewax, 2 to 5 parts of polyethylene wax, 0 to 5 parts of stearic acid, 0 to 5 parts of ethylene-vinyl acetate copolymer, 5 to 15 parts of C9 petroleum resin, 5 to 15 parts of hydrogenated C9 petroleum resin, 5 to 15 parts of hydrogenated terpene resin, 0 to 8 parts of polymethyl methacrylate and 5 to 15 parts of D-mannitol. The investment casting pattern material disclosed by the invention is relatively high in bending strength and surface hardness, high in surface smoothness and good in dimensional stability, and can be widely applied to the field of high-precision casting.

Description

Technical Field

[0001] The present invention belongs to the technical field of investment casting wax materials, and specifically relates to a preparation method and application of investment casting wax.

Background Art

[0002] Precision casting is an advanced material forming process. Its castings are precise, complex, and close to the final shape of the part, and can be used directly without machining or with very little machining. In the precision casting process, the dimensional accuracy of the wax pattern directly determines and affects the dimensional accuracy of the final product. Traditional wax has always been used as a general model material for the investment casting process. With the increasing demand for precise dimensions and complex shapes, various materials have been mixed with wax to develop models more suitable for investment casting to overcome the performance limitations exhibited by traditional wax.

[0003] For precision castings, the most important performance index is dimensional accuracy, which requires the shrinkage rate of precision casting wax to be as low as possible. See the Chinese patent document with the patent document number CN110205092A, which proposes a preparation method of repair wax for investment casting; the Chinese patent document with the patent document number CN108329701A gives a preparation method of investment casting wax; the Chinese patent document with the patent document number CN109265847A proposes a preparation method of quick-drying composite wax for investment casting. These patent documents mainly solve process problems such as demoulding property, product surface finish, and forming speed, and involve less in the strength performance, dimensional stability, and operability of investment casting wax.

Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a preparation method and application of investment casting wax.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: A method for preparing investment casting wax, the preparation method comprising the following steps: (1) Add paraffin wax, beeswax and montan wax into a polymerization bottle, heat at 80 - 100 °C, and stir until completely melted; (2) Continue to raise the temperature to 90 - 100 °C, add polyethylene wax and stearic acid and melt them, and stir until completely melted; (3) Continue to raise the temperature to 110 - 120 °C, add ethylene-vinyl acetate copolymer, keep warm for 60 - 90 min, and continuously stir until melted; (4) Add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, and keep warm at 120 °C for 60 - 90 min, stir slowly, wait until completely melted into a transparent state, cool down to 100 °C, start slow stirring until evenly mixed; (5) Add D-mannitol and polymethyl methacrylate successively at 90 - 100 °C, continuously stir until evenly mixed, keep warm for 60 - 90 min, and make granules after cooling to obtain investment casting wax; in the above preparation method, the mass ratio of each component is: paraffin wax: 15 - 25 parts, montan wax: 10 - 20 parts, C5 petroleum resin: 15 - 20 parts, beeswax: 2 - 10 parts, polyethylene wax: 2 - 5 parts, stearic acid: less than 5 parts, ethylene-vinyl acetate copolymer: less than 5 parts, C9 petroleum resin: 5 - 15 parts, hydrogenated C9 petroleum resin: 5 - 15 parts, hydrogenated terpene resin: 5 - 15 parts, polymethyl methacrylate less than 8 parts, D-mannitol 5 - 15 parts.

[0006] Furthermore, in the above method for preparing investment casting wax, the melting point of the paraffin wax is 60 - 62 °C; the melting point of the montan wax is 75 - 86 °C; the melting point of the beeswax is 62 - 67 °C.

[0007] Furthermore, in the above method for preparing investment casting wax, the melting point of the polyethylene wax is 90 - 100 °C, and the average relative molecular mass is 1500 - 2000.

[0008] Furthermore, in the above method for preparing investment casting wax, the content of vinyl acetate copolymer in the ethylene-vinyl acetate copolymer is 28 wt%, and the melt index is 400 g / 10 min.

[0009] Furthermore, in the above method for preparing investment casting wax, the melting point of the stearic acid is 67 - 72 °C; the melting point of the C5 petroleum resin is 80 - 100 °C; the melting point of the C9 petroleum resin is 100 - 120 °C; the melting point of the hydrogenated C9 petroleum resin is 100 - 130 °C; the melting point of the hydrogenated terpene resin is 80 - 90 °C.

[0010] Furthermore, in the above method for preparing investment casting wax, the polymethyl methacrylate can pass through a 500-mesh sieve, with a particle size of 25 microns and a relative molecular mass of 150000.

[0011] Furthermore, in the above method for preparing investment casting wax, the purity of D-mannitol is ≥99.0%, and 100% of D-mannitol and polymethyl methacrylate can pass through a 100-mesh sieve, and 80% can pass through a 200-mesh sieve.

[0012] The application of an investment casting wax in the present invention adopts the following technical solution: The investment casting wax is prepared by the above method for preparing an investment casting wax, and the investment casting wax is applied to prepare a wax model of a high-precision aviation casting structural part.

[0013] The inventor of the present invention designed and studied a resin-modified wax based on a precision casting wax composite formula and preparation process, introduced wax materials such as polyethylene wax and beeswax, hydrogenated C9 resin, hydrogenated terpene resin, and functional aids such as D-mannitol, and adjusted the composition and proportion of the wax mold material after a large number of tests, and improved the shrinkage rate, surface hardness, viscosity, and bending strength of the precision casting wax, and reduced the shrinkage rate; the influence of properties such as melting point, adjusted the composition and proportion of the wax mold material, and finally achieved the purpose of high bending hardness and surface hardness of the precision casting wax and reducing the shrinkage rate of the precision casting wax. The investment casting wax prepared by the present invention can reach the level of high-standard products of the same type abroad.

Specific Embodiments

[0014] The present invention relates to a method for preparing an investment casting wax and a specific application of the investment casting wax prepared by this preparation method.

[0015] When preparing the investment casting wax of the present invention, prepare raw materials according to the following mass component ratios:

[0016] (1) 15 - 25 parts of paraffin wax;

[0017] (2) 10 - 20 parts of lignite wax;

[0018] (3) 15 - 20 parts of C5 petroleum resin;

[0019] (4) 2 - 10 parts of beeswax;

[0020] (5) 2 - 5 parts of polyethylene wax;

[0021] (6) 0 - 5 parts of stearic acid (when the value is 0, it means not adding);

[0022] (7) 0 - 5 parts of ethylene-vinyl acetate copolymer (when the value is 0, it means not adding);

[0023] (8) 5 - 15 parts of C9 petroleum resin;

[0024] (9) 5 - 15 parts of hydrogenated C9 petroleum resin;

[0025] (10) 5 - 15 parts of hydrogenated terpene resin;

[0026] (11) 5 - 15 parts of D - mannitol;

[0027] (12) 0 - 8 parts of polymethyl methacrylate (when the value is 0, it means not added).

[0028] The total of the above components is 100 parts.

[0029] The melting point of the paraffin wax is 60 - 62 °C, which is 60# fully refined paraffin wax. The melting point of the lignite wax is 75 - 86 °C. The melting point of the beeswax is 62 - 67 °C. The melting point of the polyethylene wax is 90 - 100 °C, and the average relative molecular mass is 1500 - 2000. The vinyl acetate content in the ethylene - vinyl acetate copolymer is 28 wt%, and the melt index is 400 g / 10 min. The melting point of the stearic acid is 67 - 72 °C. The melting point of the C5 petroleum resin is 80 - 100 °C. The melting point of the C9 petroleum resin is 100 - 120 °C. The melting point of the hydrogenated C9 petroleum resin is 100 - 130 °C. The melting point of the hydrogenated terpene resin is 80 - 90 °C. The D - mannitol is of ultra - pure grade, ≥99.0% (HPLC). The D - mannitol, tapioca starch, and polymethyl methacrylate can all pass through a 100 - mesh sieve, 80% can pass through a 200 - mesh sieve. Preferably, the polymethyl methacrylate can pass through a 500 - mesh sieve, with a particle size of 25 microns and a relative molecular mass of 150000.

[0030] The preparation method of the present invention is carried out according to the following steps.

[0031] (1) Add paraffin wax, beeswax, and lignite wax into a polymerization flask, heat at 80 - 100 °C, and continuously stir for 20 - 30 min until completely melted.

[0032] (2) Continue to raise the temperature to 90 - 100 °C, add polyethylene wax and stearic acid to melt, and continuously stir for 10 - 20 min until completely melted.

[0033] (3) Continue to raise the temperature to 110 - 120 °C, add ethylene - vinyl acetate copolymer, keep warm for 60 - 90 min, and continuously stir until melted.

[0034] (4) Add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, keep warm at 120 °C for 60 - 90 min, stir slowly, wait until completely melted into a transparent state, cool down to 100 °C, and start slow stirring until evenly mixed.

[0035] (5) Add D-mannitol and polymethyl methacrylate successively at 90-100 °C, continuously stir until evenly mixed, keep warm for 60-90 min, and make granules after cooling to obtain the precision casting wax.

[0036] The obtained precision casting wax can be melt-injected by any injection machine to produce various types of small mold parts. Test various properties of the small mold parts, and the test methods are as follows:

[0037] Melting point: Use DSC to test the melting point of the precision casting wax;

[0038] Hardness: Use a Shore hardness tester to test the hardness of the precision casting wax;

[0039] Viscosity: Implement according to the method specified in GB / T14235.1;

[0040] Flexural strength: Implement according to the method specified in GB / T14235.1;

[0041] Linear shrinkage rate: Implement according to the method specified in GB / T14235.1;

[0042] Ash content: Use TG to test the residual ash content of the precision casting wax.

[0043] After testing, the investment casting wax prepared by the present invention has the following performance characteristics:

[0044] The viscosity is 190-590 mPa·s;

[0045] The shrinkage rate is 0.3%-0.6%, ensuring the stability during the casting process;

[0046] The flexural strength is 5-9 MPa, and the hardness is between 32-56, endowing the wax with high strength and high hardness, thereby improving the precision of the casting;

[0047] The ash content is less than 0.02%, ensuring no pollution during the casting process;

[0048] The melting point is between 49-59 °C.

[0049] The above-mentioned characteristics together improve the efficiency of investment precision casting. In addition, the hydrogenated resin in the casting wax of the present invention can be well dispersed at the interface of the casting wax components, making the region homogeneous, reducing the linear shrinkage rate and improving the mechanical properties of the mold material. The internal components of the wax are uniform, the shrinkage rate is consistent, and the strength is relatively high. It can be widely used in the preparation of wax models for high-precision aviation casting structural parts and wax models for other precision castings.

[0050] The investment casting wax of the present invention will be further described in detail below in conjunction with the embodiments of the present invention:

[0051] Example 1

[0052] The raw materials and mass component ratios of this investment casting wax are as follows: 35 parts of paraffin wax, 25 parts of lignite wax, 35 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 15 parts of C9 petroleum resin, 20 parts of hydrogenated C9 petroleum resin, 15 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 5 parts of ethylene-vinyl acetate copolymer, and 30 parts of D-mannitol. The total of the above components is 200 parts.

[0053] Stearic acid is not added in the first embodiment.

[0054] Its preparation method includes the following steps:

[0055] (1) Add paraffin wax, beeswax and lignite wax into a polymerization flask, heat at 90 °C, and continuously stir for 20 min until completely melted;

[0056] (2) Continue to raise the temperature to 100 °C, add polyethylene wax and melt it, and continuously stir for 20 min until completely melted;

[0057] (3) Continue to raise the temperature to 120 °C, add ethylene-vinyl acetate copolymer, keep warm for 60 min, and continuously stir until melted;

[0058] (4) Add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, keep warm at 120 °C for 90 min, stir slowly, wait until completely melted into a transparent state, cool down to 100 °C, start slow stirring, and stir until evenly mixed;

[0059] (5) Add D-mannitol and polymethyl methacrylate successively at 100 °C, continuously stir until evenly mixed, keep warm for 60 min, and make granules after cooling to obtain precision casting wax.

[0060] Example 2:

[0061] The raw materials and mass component ratios of Example 2 are as follows: 30 parts of paraffin wax, 30 parts of lignite wax, 35 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 10 parts of C9 petroleum resin, 30 parts of hydrogenated C9 petroleum resin, 20 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 5 parts of ethylene-vinyl acetate, and 20 parts of D-mannitol. The total of the above components is 200 parts.

[0062] Its preparation method includes the following steps:

[0063] (1) Add paraffin wax, beeswax and lignite wax into a polymerization flask, heat at 90 °C, and continuously stir for 20 min until completely melted;

[0064] (2) Continue to raise the temperature to 100 °C, add polyethylene wax and melt it, and continuously stir for 20 min until completely melted;

[0065] (3) Continue to raise the temperature to 120 °C, add ethylene-vinyl acetate copolymer, keep the temperature for 60 min, and continuously stir until melted;

[0066] (4) Add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, keep the temperature at 120 °C for 90 min, stir slowly, wait until it is completely melted and transparent, cool down to 100 °C, start slow stirring until evenly mixed;

[0067] (5) Add D-mannitol and polymethyl methacrylate respectively at 100 °C, continuously stir until evenly mixed, keep the temperature for 60 min, and make granules after cooling to obtain precision casting wax.

[0068] Example 3:

[0069] The raw materials and mass component ratios of Example 3 are: 40 parts of paraffin wax, 30 parts of lignite wax, 30 parts of C5 petroleum resin, 5 parts of polymethyl methacrylate, 15 parts of C9 petroleum resin, 15 parts of hydrogenated C9 resin, 30 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 5 parts of ethylene-vinyl acetate, and 20 parts of D-mannitol. The total of the above components is 200 parts.

[0070] Its preparation method includes the following steps:

[0071] (1) Add paraffin wax, beeswax, and lignite wax to the polymerization flask, heat at 90 °C, and continuously stir for 20 min until completely melted;

[0072] (2) Continue to raise the temperature to 100 °C, add polyethylene wax and melt it, and continuously stir for 20 min until completely melted;

[0073] (3) Continue to raise the temperature to 120 °C, add ethylene-vinyl acetate copolymer, keep the temperature for 60 min, and continuously stir until melted;

[0074] (4) Add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, keep the temperature at 120 °C for 90 min, stir slowly, wait until it is completely melted and transparent, cool down to 100 °C, start slow stirring until evenly mixed;

[0075] (5) Add D-mannitol and polymethyl methacrylate respectively at 100 °C, continuously stir until evenly mixed, keep the temperature for 60 min, and make granules after cooling to obtain precision casting wax.

[0076] Example 4:

[0077] The raw materials and mass component ratios of Example 4 are as follows: 40 parts of paraffin wax, 20 parts of montan wax, 35 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 15 parts of C9 petroleum resin, 20 parts of hydrogenated C9 petroleum resin, 10 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 15 parts of beeswax, 25 parts of D-mannitol, and 5 parts of stearic acid. The total of the above components is 200 parts.

[0078] Its preparation method comprises the following steps:

[0079] (1) Add paraffin wax, beeswax and montan wax into a polymerization flask, heat at 90 °C, and continuously stir for 20 min until completely melted;

[0080] (2) Continue to raise the temperature to 100 °C, add polyethylene wax and stearic acid and melt them, and continuously stir for 20 min until completely melted;

[0081] (3) Continue to raise the temperature to 120 °C, add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, and keep them at 120 °C for 90 min with slow stirring, wait until completely melted into a transparent state, cool down to 100 °C, and start slow stirring until evenly mixed;

[0082] (4) Add D-mannitol and polymethyl methacrylate successively at 90 °C, continuously stir until evenly mixed, keep warm for 60 min, and make granules after cooling to obtain precision casting wax.

[0083] Example 5:

[0084] The raw materials and mass component ratios of Example 5 are as follows: 45 parts of paraffin wax, 20 parts of montan wax, 30 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 15 parts of C9 petroleum resin, 20 parts of hydrogenated C9 petroleum resin, 10 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 20 parts of D-mannitol, and 5 parts of stearic acid. The total of the above components is 200 parts.

[0085] Its preparation method comprises the following steps:

[0086] (1) Add paraffin wax, beeswax and montan wax into a polymerization flask, heat at 90 °C, and continuously stir for 20 min until completely melted;

[0087] (2) Continue to raise the temperature to 100 °C, add polyethylene wax and stearic acid and melt them, and continuously stir for 20 min until completely melted;

[0088] (3) Continue to raise the temperature to 120 °C, add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, and keep them at 120 °C for 90 min with slow stirring, wait until completely melted into a transparent state, cool down to 100 °C, and start slow stirring until evenly mixed;

[0089] (4) At 90 °C, D-mannitol and polymethyl methacrylate are added sequentially, and stirring is continued until evenly mixed. It is kept warm for 60 min, and then granulated after cooling to obtain the precision casting wax.

[0090] Comparative Example 1:

[0091] The raw materials and mass component ratios of Comparative Example 1 are as follows: 25 parts of paraffin wax, 25 parts of lignite wax, 35 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 15 parts of C9 petroleum resin, 5 parts of hydrogenated C9 petroleum resin, 35 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 5 parts of ethylene-vinyl acetate, 30 parts of D-mannitol, and 5 parts of stearic acid.

[0092] Among the above components, the amounts of paraffin wax, hydrogenated C9 petroleum resin, and hydrogenated terpene resin exceed the dosage ranges defined in the present invention.

[0093] The preparation method is the same as that of Example 1.

[0094] Comparative Example 2:

[0095] The raw materials and mass component ratios of Comparative Example 2 are as follows: 35 parts of paraffin wax, 20 parts of lignite wax, 30 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 35 parts of C9 petroleum resin, 35 parts of hydrogenated C9 petroleum resin, 5 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 5 parts of ethylene-vinyl acetate, 25 parts of D-mannitol, and 5 parts of stearic acid.

[0096] Among the above components, the amounts of C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin exceed the dosage ranges defined in the present invention.

[0097] The preparation method is the same as that of Example 1.

[0098] Comparative Example 3:

[0099] The raw materials and mass component ratios of Comparative Example 3 are as follows: 30 parts of paraffin wax, 20 parts of lignite wax, 35 parts of C5 petroleum resin, 25 parts of polymethyl methacrylate, 5 parts of C9 petroleum resin, 10 parts of hydrogenated C9 resin, 30 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 0 parts of ethylene-vinyl acetate, 30 parts of D-mannitol, and 5 parts of stearic acid.

[0100] Among the above components, the amounts of polymethyl methacrylate and C9 petroleum resin exceed the dosage ranges defined in the present invention.

[0101] The preparation method is the same as that of Example 1.

[0102] Comparative Example 4:

[0103] The raw materials and mass component ratios of Comparative Example 4 are as follows: 35 parts of paraffin wax, 25 parts of lignite wax, 35 parts of C5 petroleum resin, 10 parts of polymethyl methacrylate, 5 parts of C9 petroleum resin, 10 parts of hydrogenated C9 resin, 30 parts of hydrogenated terpene resin, 5 parts of polyethylene wax, 5 parts of beeswax, 15 parts of ethylene-vinyl acetate, and 25 parts of D-mannitol.

[0104] Among the above components, the amounts of polymethyl methacrylate, C9 petroleum resin, and ethylene-vinyl acetate exceed the dosage ranges defined in the present invention.

[0105] The preparation method is the same as that of Example 1.

[0106] Comparative Example 5:

[0107] The raw materials and mass component ratios of Comparative Example 5 are as follows: 40 parts of paraffin wax, 20 parts of lignite wax, 35 parts of C5 petroleum resin, 15 parts of polymethyl methacrylate, 5 parts of C9 petroleum resin, 10 parts of hydrogenated C9 resin, 30 parts of hydrogenated terpene resin, 15 parts of polyethylene wax, 5 parts of beeswax, 5 parts of ethylene-vinyl acetate, and 30 parts of D-mannitol.

[0108] Among the above components, the amounts of polymethyl methacrylate, C9 petroleum resin, and polyethylene wax exceed the dosage ranges defined in the present invention.

[0109] The preparation method is the same as that of Example 1.

[0110] The casting waxes prepared in the above Examples 1 to 5 and Comparative Examples 1 to 5 were used to make small mold parts through an injection machine, and side inspections were carried out. The test performances are shown in Table 1 below.

[0111] Table 1: Performance test data of investment casting wax

[0112]

[0113] As can be seen from Table 1, the investment casting wax of the present invention has a moderate melting point, a small linear shrinkage rate, high hardness, high bending strength, small ash content, and good viscosity controllability. At the same time, it can also be seen from Table 1 that when certain components in the investment casting wax formula exceed the range, it has a great impact on the comprehensive performance, especially the shrinkage rate of the precision casting wax obtained will increase significantly.

[0114] The above are the better technical solutions of the embodiments of the present invention. The above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them. Those of ordinary skill in the art can still modify or equivalently replace the technical solutions of the embodiments of the present invention, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the scope of the technical plan of the embodiments of the present invention.

Claims

1. A method for preparing investment casting wax, characterized in that: The preparation method comprises the following steps: (1) Add paraffin, beeswax and montan wax into a polymerization bottle, heat at 80-100°C, and stir until completely melted; (2) Continue to raise the temperature to 90-100°C, add polyethylene wax and stearic acid to melt, and stir until completely melted; (3) Continue to raise the temperature to 110-120°C, add ethylene-vinyl acetate copolymer, keep the temperature for 60-90 minutes, and stir continuously until it melts; (4) Add C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, and hydrogenated terpene resin to the above materials, and keep the temperature at 120° C. for 60 to 90 minutes, slowly stir, wait until it is completely melted into a transparent state, cool to 100° C., start slow stirring, and mix evenly; (5) adding D-mannitol and polymethyl methacrylate in sequence at 90-100° C., stirring continuously until the mixture is uniformly mixed, keeping the mixture at the temperature for 60-90 min, and cooling the mixture to form granules to obtain investment casting wax; In the above preparation method, the mass ratio of each component is: Paraffin: 15-25 parts, montan wax: 10-20 parts, C5 petroleum resin: 15-20 parts, beeswax: 2-10 parts, polyethylene wax: 2-5 parts, stearic acid: less than 5 parts, ethylene-vinyl acetate copolymer: less than 5 parts, C9 petroleum resin: 5-15 parts, hydrogenated C9 petroleum resin: 5-15 parts, hydrogenated terpene resin: 5-15 parts, polymethyl methacrylate less than 8 parts, D-mannitol 5-15 parts.

2. The method for preparing investment casting wax according to claim 1, characterized in that: The melting point of the paraffin wax is 60-62°C; the melting point of the montan wax is 75-86°C; and the melting point of the beeswax is 62-67°C.

3. The method for preparing investment casting wax according to claim 1, characterized in that: The polyethylene wax has a melting point of 90-100° C. and an average relative molecular mass of 1500-2000.

4. The method for preparing investment casting wax according to claim 1, characterized in that: The vinyl acetate copolymer content in the ethylene-vinyl acetate copolymer is 28 wt % and the melt index is 400 g / 10 min.

5. The method for preparing investment casting wax according to claim 1, characterized in that: The melting point of the stearic acid is 67-72°C; the melting point of the C5 petroleum resin is 80-100°C; the melting point of the C9 petroleum resin is 100-120°C; the melting point of the hydrogenated C9 petroleum resin is 100-130°C; and the melting point of the hydrogenated terpene resin is 80-90°C.

6. The method for preparing investment casting wax according to claim 1, characterized in that: The polymethyl methacrylate can pass through a 500-mesh sieve, is 25 microns, and has a relative molecular mass of 150,000.

7. The method for preparing investment casting wax according to claim 1, characterized in that: The purity of the D-mannitol is ≥99.0%, and 100% of the D-mannitol and polymethyl methacrylate can pass through a 100-mesh sieve, and 80% can pass through a 200-mesh sieve.

8. An application of investment casting wax, characterized in that: The investment casting wax is prepared by the investment casting wax preparation method described in any one of claims 1 to 7, and the investment casting wax is used for preparing wax models of high-precision aviation casting structural parts.

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