阅读说明：本技术 熔模粉末 (Investment powder ) 是由 S·R·古德温 M·G·帕林 于 2020-03-26 设计创作，主要内容包括：一种比传统粉末更安全的熔模粉末,包含磷酸三钙,并且在呼吸部分中基本上或完全不含游离二氧化硅,但提供750℃下1％或更高的总膨胀,足以防止铸造期间模具开裂。一种制造铸件的方法,包括：通过将石膏粘合熔模粉末与水混合形成浆料,将浆料围绕低熔点材料模型倒入不锈钢烧瓶中,让浆料凝固以限定模具,加热模具以燃尽模型和将材料浇铸到模具中,其中不锈钢烧瓶由400系列马氏体不锈钢组成。(An investment powder that is safer than conventional powders, comprises tricalcium phosphate and is substantially or completely free of free silica in the breath portion, but provides a total expansion of 1% or more at 750 ℃ sufficient to prevent mold cracking during casting. A method of making a casting, comprising: the method includes forming a slurry by mixing gypsum-bonded investment powder with water, pouring the slurry around a low-melting material pattern into a stainless steel flask, allowing the slurry to set to define a mold, heating the mold to burn off the pattern and casting the material into the mold, wherein the stainless steel flask consists of a 400 series martensitic stainless steel.)

1. A gypsum-bonded investment powder comprising tricalcium phosphate and less than 1% by weight free silica in the respiratory portion.

2. The investment powder of claim 1, further comprising stucco.

3. The investment powder of claim 2 or claim 3, comprising from greater than 30% to 70% by weight tricalcium phosphate.

4. The investment powder of any one of the preceding claims, wherein the stucco comprises dry stucco.

5. The investment powder of any one of the preceding claims, comprising magnesium oxide.

6. The investment powder of any one of the preceding claims, further comprising one or more low silica minerals.

7. The investment powder of any one of the preceding claims, comprising:

10 to 30% of stucco

25 to 75% tricalcium phosphate

10 to 65% magnesium oxide

0 to 25% of one or more low-silica minerals

0 to 10% of additives.

8. The investment powder of claim 6 or claim 7, wherein the low silica mineral is selected from the group consisting of vermiculite, spongite kyanite, chlorite, feldspar, mica and talc.

9. The investment powder of any one of the preceding claims, including one or more wetting agents, defoamers, suspending agents, accelerators or retarders as additives.

10. The investment powder of any one of the preceding claims, having a total expansion at 750 ℃ of greater than 0.7%, preferably greater than 1%, and more preferably greater than 2% when formed into an investment casting mold.

11. An investment powder substantially as hereinbefore described.

12. A method of making an investment casting slurry by mixing the investment powder of any one of claims 1 to 11 with water.

13. A method of making a casting comprising forming a slurry according to claim 12, pouring the slurry around a pattern of low melting point material, allowing the slurry to set to define a mold, heating the mold to burn off the pattern and casting material into the mold.

14. Use of a composition comprising as an investment powder

10 to 30% of stucco

25 to 75% tricalcium phosphate

10 to 65% magnesium oxide

0 to 25% of one or more low-silica minerals

0 to 10% of additives.

15. A method of making a casting, comprising: the method includes forming a slurry by mixing gypsum-bonded investment powder with water, pouring the slurry around a low-melting material pattern into a stainless steel flask, allowing the slurry to set to define a mold, heating the mold to burn off the pattern and casting the material into the mold, wherein the stainless steel flask consists of a 400 series martensitic stainless steel.

16. The method of claim 15, wherein the 400 series martensitic stainless steel is 410 stainless steel.

17. The method of claim 15 or claim 16, wherein the investment powder comprises an investment powder comprising stucco and calcium phosphate.

18. The method of claim 17 wherein the investment powder comprises tricalcium phosphate.

19. The method of claim 17 or 18, wherein the investment powder further comprises magnesium oxide.

20. The method of any one of claims 17 to 19 wherein the investment powder further comprises one or more low silica minerals.

21. The method of any one of claims 15 to 20, wherein the investment powder comprises dry stucco.

22. The method of any one of claims 15 to 21, wherein the investment powder comprises:

10 to 30% of stucco

25 to 75% calcium phosphate

10 to 65% magnesium oxide

0 to 25% of one or more low-silica minerals

0 to 10% of additives.

23. The method of any one of claims 15 to 22, wherein the investment powder comprises one or more wetting agents, defoamers, suspending agents, accelerators or retarders as additives.

24. The method of any one of claims 15 to 23, wherein the investment powder is as defined in any one of claims 1 to 11.