KR100320042B1 - Gypsum-bonded Investment - Google Patents
Gypsum-bonded Investment Download PDFInfo
- Publication number
- KR100320042B1 KR100320042B1 KR1019990017249A KR19990017249A KR100320042B1 KR 100320042 B1 KR100320042 B1 KR 100320042B1 KR 1019990017249 A KR1019990017249 A KR 1019990017249A KR 19990017249 A KR19990017249 A KR 19990017249A KR 100320042 B1 KR100320042 B1 KR 100320042B1
- Authority
- KR
- South Korea
- Prior art keywords
- gypsum
- cristobalite
- casting
- mixing ratio
- investment material
- Prior art date
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- 239000000463 material Substances 0.000 claims abstract description 32
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910052602 gypsum Inorganic materials 0.000 claims abstract description 28
- 239000010440 gypsum Substances 0.000 claims abstract description 28
- 229910052906 cristobalite Inorganic materials 0.000 claims abstract description 26
- 238000005266 casting Methods 0.000 claims abstract description 16
- 239000002184 metal Substances 0.000 claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 claims abstract description 15
- 238000005495 investment casting Methods 0.000 claims abstract description 11
- 229910001316 Ag alloy Inorganic materials 0.000 claims description 7
- 229910001020 Au alloy Inorganic materials 0.000 claims description 7
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 7
- 239000010931 gold Substances 0.000 claims description 7
- 239000010970 precious metal Substances 0.000 claims description 3
- 230000007423 decrease Effects 0.000 description 4
- 230000003796 beauty Effects 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000008262 pumice Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
- B22C1/08—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives for decreasing shrinkage of the mould, e.g. for investment casting
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
- B22C1/181—Cements, oxides or clays
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
- B22C1/186—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents contaming ammonium or metal silicates, silica sols
Abstract
본 발명은 주조금속의 정밀주조를 위한 석고계 매몰재에 관한 것으로, 경석고와 크리스토발라이트를 적정한 혼합비로 함유하는 것을 특징으로 하며, 본 발명에 따라 경석고와 내화물인 크리스토발라이트의 혼합량을 변화시켜 주면 주조금속의 주조수축을 보상할 수 있는 적정한 팽창량을 얻을 수 있는 혼합비를 얻어낼 수 있고, 이러한 혼합비로 경석고와 크리스토발라이트가 배합된 매몰재를 사용하면 주조체의 치수정밀도 및 주조체 표면의 미려도를 향상시켜 상품성을 크게 향상시킬 수 있게 된다.The present invention relates to a gypsum-based investment material for precision casting of cast metal, characterized in that it contains hard gypsum and cristobalite in a suitable mixing ratio, according to the present invention by changing the amount of the hard gypsum and refractory cristobalite casting of cast metal A mixing ratio can be obtained to obtain an adequate amount of expansion to compensate for shrinkage, and by using a buried material containing hard gypsum and cristobalite at this mixing ratio, the dimensional accuracy of the cast and the beautifulness of the cast surface can be improved. It can be greatly improved.
Description
본 발명은 주조금속의 정밀주조용 매몰재에 관한 것으로서, 특히 치과분야와 귀금속분야에서 금·은 합금의 정밀주조를 위한 석고계 매몰재(Gypsum-bonded Investment)에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to investment casting materials for precision casting of cast metals, and more particularly to gypsum-bonded investment for precision casting of gold and silver alloys in dental and precious metals.
석고계 매몰재는 비교적 융점이 높지 않는 금·은 합금 및 동합금의 주조에 사용되며 주조체의 미려도 및 정밀한 부위의 재현성이 우수하여 귀금 속의 정밀주조에 많이 사용되고 있다. 일반적으로 치과주조용 매몰재는 주조시 합금의 주조수축을 매몰재 자체의 팽창으로 보상시켜 주어야 하며 적당한 가사시간 및 경화시간,강도, 미세부위의 재현성, 통기성 및 내열성 등의 특성이 요구된다. 이를 위하여 실리카의 종류 및 입도분포와 배합비, 결합재의 종류와 배합비 및 첨가제의 종류와 배합비 등의 변수를 사용하여 매몰재를 제조할 수 있다.Gypsum-based investment materials are used for casting gold and silver alloys and copper alloys that do not have a relatively high melting point. They are widely used for precision casting in precious metals due to their excellent beauty and reproducibility of precise parts. In general, the investment casting material for dental casting should compensate the casting shrinkage of the alloy during the casting by the expansion of the investment material itself, and requires characteristics such as proper pot life and curing time, strength, reproducibility of fine parts, breathability and heat resistance. For this purpose, the investment material may be manufactured using variables such as the type and the particle size distribution and the mixing ratio of the silica, the type and the mixing ratio of the binder, and the type and the mixing ratio of the additive.
지금까지 개발된 석고계 매몰재는 국 내에서의 개발은 전무하며 외국에서 개발되어 수입중인 석고계 매몰재는 금·은 합금의 주조수축을 충분히 보상하지 못하는 문제점을 않고 있다.The gypsum investment materials developed so far have never been developed in Korea, and the gypsum investment materials developed and imported in foreign countries do not sufficiently compensate for the casting shrinkage of gold and silver alloys.
따라서 본 발명은 상기의 제반 문제점을 감안하여 주조금속의 주조수축을 충분히 보상하여 주조체의 치수정밀도 및 주조체 표면의 미려도를 향상시킬 수 있는 석고계 매몰재를 제공하는 것을 목적으로 한다.Accordingly, an object of the present invention is to provide a gypsum-based investment material capable of sufficiently compensating the casting shrinkage of a cast metal to improve the dimensional accuracy of the cast and the beauty of the cast surface.
상기한 과제를 해결하기 위한 본 발명자의 연구에서 내화물인 크리스토발라이트에 결합재로 비교적 균질하고 밀도가 치밀한 경석고를 사용, 두가지 조성을 적절히 변화시키면 주조금속의 주조수축을 충분히 보상하도록 할 수 있음을 알게되어 본 발명을 완성하게 된 것이다.In the study of the present inventors to solve the above problems, using a relatively homogeneous and dense hard stone as a binder in the refractory cristobalite, it was found that by properly changing the two compositions can be sufficiently compensated the casting shrinkage of the cast metal Will be completed.
도 1은 크리스토발라이트의 함량이 증대될수록 열팽창율이 증대되는 것을 보여주는 매몰재의 열팽창특성 그래프이고,1 is a thermal expansion characteristic graph of the investment material showing that the thermal expansion rate increases as the content of cristobalite increases,
도 2는 크리스토발라이트의 함량이 증대될수록 경화팽창율이 감소하는 것을 보여주는 매몰재의 경화팽창특성 그래프이다.Figure 2 is a graph of the hardening expansion characteristics of the investment material showing that the hardening expansion rate decreases as the content of cristobalite increases.
그러므로 본 발명에 의하면 주조금속의 정밀주조를 위한 석고계 매몰재에 있어서, 경석고와 크리스토발라이트(cristobalite)를 매몰재가 주조금속의 주조수축을 보상하는 수축특성을 갖는 정도의 혼합비율로 함유하는 것을 특징으로 하는 석고계 매몰재가 제공된다.Therefore, according to the present invention, in the gypsum-based investment material for precision casting of cast metal, the hard gypsum and cristobalite is contained in a mixing ratio such that the investment material has a shrinkage property to compensate for casting shrinkage of the cast metal. Gypsum-based investment material is provided.
이하, 본 발명을 보다 상세하게 설명하기로 한다.Hereinafter, the present invention will be described in more detail.
본 발명에 따르는 금·은 합금과 같은 주조금속의 정밀 주조용 석고계 매몰재는 로스트왁스법에 의한 주조 금속의 부피수축을 보상하도록 경석고에 내화물인 크리스토발라이트를 적정 비율로 첨가하여 주조금속의 주조수축을 충분히 보상하는 매몰재의 선팽창을 얻을 수 있도록 설정한 것이다.The gypsum-based investment material for precision casting of cast metals such as gold and silver alloys according to the present invention adds refractory cristobalite to the hard gypsum at an appropriate ratio to compensate for volume shrinkage of the cast metal by the lost wax method to reduce casting shrinkage of the cast metal. It is set so that the linear expansion of the investment material which fully compensates is obtained.
본 발명에 따라 경석고와 크리스토발라이트의 혼합비율을 적절히 변화시키면 목적하는 열적 선팽창을 얻을 수 있게 된다. 즉, 본 발명의 주된 특징은 경석고와 크리스토발라이트를 적정 비율로 혼합하여 매몰재에 가장 적정한 경화팽창과 열팽창을 부여하는 것이다.According to the present invention, if the mixing ratio of hard gypsum and cristobalite is properly changed, the desired thermal linear expansion can be obtained. In other words, the main feature of the present invention is to mix hard gypsum and cristobalite in an appropriate ratio to give the investment material the most appropriate curing expansion and thermal expansion.
경석고와 크리스토발라이트의 혼합비율과 매몰재의 경화팽창 또는 열팽창간의 관계에 대해 연구한 결과에 의하면, 경석고와 크리스토발라이트의 혼합에서 크리스토발라이트의 혼합비가 증가할수록 경화팽창이 감소하고, 열팽창은 증가하는 것으로 나타난다. 이렇게 팽창의 변화가 일어나는 것은 경화팽창에서 크리스토발라이트의 혼합비가 증가할수록 상대적으로 경석고의 함량이 감소하기 때문이며, 열팽창에서는 크리스토발라이트의 함량이 증가할수록 경석고의 열적수축의 여지는 점점 사라져가고 크리스토발라이트의 열적팽창의 특성이 점점 두드러지기 때문이다.The relationship between the mixing ratio of hard gypsum and cristobalite and the hardening expansion or thermal expansion of investment material shows that the hardening expansion decreases and the thermal expansion increases as the mixing ratio of cristobalite increases in the mixing of hard gypsum and cristobalite. This change in expansion occurs because the content of pumice gypsum decreases as the mixing ratio of cristobalite increases in hardening expansion. Because this is getting noticeable.
따라서 경석고와 크리스토발라이트의 혼합비율을 적절히 조절하면 주조금속의 주조수축을 충분히 보상하는 수축특성을 매몰재에 부여할 수 있게 되는 것이다.Therefore, if the mixing ratio of hard gypsum and cristobalite is properly adjusted, it is possible to give the investment material a shrinkage property that sufficiently compensates the casting shrinkage of the cast metal.
특별히 제한하기 위한 것은 아니지만 일반적으로 현재 사용하고 있는 정밀주조용 금·은 합금의 주조수축을 보상하기에 적합한 팽창을 얻기 위해 본 발명에서는 매몰재에 부여하는 경석고와 크리스토발라이트의 혼합비율은 경석고 30∼40 중량및 크리스토발라이트 60∼70중량의 범위내가 적당하다. 일반적 조성의 금·은 합금을 정밀주조하기 위한 매몰재에서 경석고와 크리스토발라이트의 혼합비율이 상기한 범위를 크게 벗어나면 주조체의 치수정밀도를 얻지 못하고 매몰재의 강도가 저하되며 주조체의 표면결함이 많이 발생된다.Although not particularly limited, the mixing ratio of pumice gypsum and cristobalite given to the investment material is 30 to 40 wt% in order to obtain expansion suitable for compensating casting shrinkage of the gold and silver alloy for precision casting currently used. And cristobalite within a range of 60 to 70 weight. If the mixing ratio of hard gypsum and cristobalite in the investment material for precision casting of gold and silver alloy of general composition is far out of the above range, the dimensional accuracy of the casting is not obtained, the strength of the investment material is lowered, and the surface defects of the casting are many. do.
위에 설명한 바와 같은 본 발명의 특징 및 기타의 장점은 하기 실시예로부터 보다 명백하게 될 것이다. 본 발명은 하기 실시예로 제한되지 않는다.Features and other advantages of the present invention as described above will become more apparent from the following examples. The invention is not limited to the following examples.
[실시예]EXAMPLE
하기 표 1에 나타낸 바와 같이 경석고와 크리스토발라이트의 혼합비율을 변화시켜 매몰재를 준비하고, 각 예에 대한 상온경화팽창과 열팽창의 특성을 실험하였다. 실험결과는 도 1 및 도 2에 제시된다. 이때, 매몰재에 대한 슬러리를 제조하기 위하여 수도물을 연화액으로 매몰재 100g당 45㎖의 비율로 사용하였으며 경화팽창의 측정시편의 크기는 10×10×50㎜로 하여 동주형에 부어 넣어 2시간 동안의 선형 경화팽창량을 측정하였으며, 열팽창은 시편크기를 φ7×12㎜로 하여 2시간 동안 경화시킨 후, 상온에서 10℃/분의 승온속도로 700℃까지 가열하고 700℃에서 10분동안 유지한 후, 상온까지 로냉하여 측정하였다.As shown in Table 1 below, the investment material was prepared by changing the mixing ratio of the hard gypsum and cristobalite, and the characteristics of room temperature hardening expansion and thermal expansion for each example were tested. The experimental results are shown in FIGS. 1 and 2. At this time, tap water was used as a softening liquid at a rate of 45 ml per 100 g of investment material to prepare a slurry for investment material, and the size of the measurement specimen for curing expansion was 10 × 10 × 50 mm and poured into a copper mold for 2 hours. Linear curing expansion was measured, and the thermal expansion was cured for 2 hours at a specimen size of φ7 × 12㎜, then heated to 700 ℃ at a heating rate of 10 ℃ / min at room temperature and maintained at 700 ℃ for 10 minutes It was measured by cooling to room temperature.
도 1의 그래프로부터 알 수 있는 바와 같이 각 예의 매몰재에 대한 열팽창특성은 크리스토발라이트의 함량이 증대될수록 열팽창율(thermal expansion)이 증대되며, 도 2의 그래프로부터 알 수 있는 바와 같이 각 예의 매몰재에 대한 경화팽창특성은 크리스토발라이트의 함량이 증대될수록 경화팽창율(setting expansion)이 감소한다.As can be seen from the graph of FIG. 1, the thermal expansion characteristics of the investment material of each example are increased as the content of cristobalite increases, and the thermal expansion is increased. As shown in the graph of FIG. 2, the curing of each investment material is shown. The expansion characteristics decrease in setting expansion as the content of cristobalite increases.
이상 설명한 바와 같이 본 발명에 따라 경석고와 내화물인 크리스토발라이트의 혼합량을 변화시켜 주면 주조금속의 주조수축을 보상할 수 있는 적정한 팽창량을 얻을 수 있는 혼합비를 얻어낼 수 있고, 이러한 혼합비로 경석고와 크리스토발라이트가 배합된 매몰재를 사용하면 주조체의 치수정밀도 및 주조체 표면의 미려도를 향상시켜 상품성을 크게 향상시킬 수 있게 된다.As described above, according to the present invention, if the mixing amount of hard gypsum and refractory cristobalite is changed, a mixing ratio can be obtained to obtain an adequate amount of expansion to compensate for casting shrinkage of the cast metal. By using the blended investment material, it is possible to improve the dimensional accuracy of the cast and the beauty of the cast surface, thereby greatly improving the merchandise.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019990017249A KR100320042B1 (en) | 1999-05-14 | 1999-05-14 | Gypsum-bonded Investment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019990017249A KR100320042B1 (en) | 1999-05-14 | 1999-05-14 | Gypsum-bonded Investment |
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| Publication Number | Publication Date |
|---|---|
| KR20000073765A KR20000073765A (en) | 2000-12-05 |
| KR100320042B1 true KR100320042B1 (en) | 2002-01-09 |
Family
ID=19585413
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1019990017249A KR100320042B1 (en) | 1999-05-14 | 1999-05-14 | Gypsum-bonded Investment |
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| Country | Link |
|---|---|
| KR (1) | KR100320042B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100864717B1 (en) | 2007-04-18 | 2008-10-23 | 주식회사 삼우 | Plastery Investment used for Investment casting |
-
1999
- 1999-05-14 KR KR1019990017249A patent/KR100320042B1/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100864717B1 (en) | 2007-04-18 | 2008-10-23 | 주식회사 삼우 | Plastery Investment used for Investment casting |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20000073765A (en) | 2000-12-05 |
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