Paghahagis ng pamumuhunan sa baso ng tubig (Kilala rin bilang sodium silicate casting) ay isang anyo ng nawala-waks paghahagis na gumagamit ng isang tubig-natutunaw sosa silicate binder sa ceramic shell.
Bilang isa sa dalawang pangunahing paraan ng paghahagis ng pamumuhunan (Ang isa pa ay silica sol), Nagbibigay ito ng balanse ng katumpakan at pagiging epektibo sa gastos.
Nagmula sa tradisyunal na mga pamamaraan ng nawawalang waks sa Asya at Europa, Ang paghahagis ng baso ng tubig ay nakakuha ng pang-industriya na traksyon noong ika-20 siglo habang ang mga pandayan ay naghanap ng isang mas mababang gastos na alternatibo sa mga proseso ng koloid-silica.
Sa pamamagitan ng paggamit ng mga karaniwang materyales (kuwarts o silica buhangin na may alkali silicate binders), Ang pamamaraang ito ay angkop para sa katamtamang katumpakan, Mga Bahagi na may mataas na kumplikado kung saan mas mahigpit ang badyet.
Ang mga karaniwang castings ng baso ng tubig ay mula sa ilang daang gramo hanggang sa 150 kg, na may maximum na sukat sa paligid ng 1m, Ginagawa itong perpekto para sa mas malaki, Mga bahagi na sensitibo sa gastos.
Ano ang Water Glass Investment Casting?
Ang paghahagis ng baso ng tubig ay isang variant ng pamumuhunan sa katumpakan (Nawawalang waks) paghahagis kung saan sosa silicate ("baso ng tubig") Nagsisilbi bilang ceramic binder.
Sa pagsasanay, waks (o plastik) Ang mga pattern ay ginawa at pinagsama-sama sa isang puno.
Paulit-ulit na ang mga pattern pinahiran sa isang slurry ng pinong refractory particle nakatali sa sodium silicate solusyon, pagkatapos ay natatakpan ng unti-unting magaspang na mga layer ng stucco upang bumuo ng shell.
Kapag gumaling na ang shell, Ang waks ay natunaw o pinakuluang, Pag-iiwan ng guwang na lukab ng amag. Tinunaw na metal (Karaniwan na bakal o bakal na haluang metal) is poured into this ceramic shell.
Pagkatapos ng solidification, the shell is broken away to reveal the cast part. Sa madaling salita, water-glass investment casting “invests” a wax master in a sodium-silicate-based ceramic to form the mold.
Compared to silica-sol investment casting (which uses colloidal silica and zircon-based sands), the water-glass method trades some surface quality for lower material cost and simpler processing.
Bakit Gumamit ng Salamin ng Tubig?
Water glass casting is popular because it reduces cost and processing relative to other precision methods.
The sodium silicate binder and conventional silica sands are inexpensive and easy to handle, so tooling and materials cost much less than for colloidal-silica shells.
Halimbawa na lang, water-glass systems avoid the high expense of silica sol and specialty sands, yielding lower per-part investment cost.
The process also eliminates many secondary operations: parts come out near-net-shape (often requiring little welding or machining).
Sa pagsasanay, water-glass castings can capture very complex geometries (with undercuts and thin webs) without cores, pagpapasimple ng disenyo.
According to industry sources, water-glass casting offers “complex design without draft angles” at “higher accuracy compared with sand casting”,
while avoiding the expensive cores, mga amag, or weldments that many large sand-cast parts need.
This flexibility makes it attractive for small-to-medium production runs where tooling costs must be minimized.
Kasabay nito, water-glass parts are generally more accurate than sand casting.
Typical dimensional tolerances are in the range of ISO CT6-CT9, roughly matching fine sand-cast tolerance classes or lower-end investment casting classes.
Surface finishes are correspondingly moderate: on the order of Ra ~6–12 μm (Ra 250–500 μin),
better than green sand casting but rougher than silica-sol investment castings.
Sa madaling salita, water-glass casting is chosen when one needs the complex shapes and reduced secondary work of lost-wax casting,
but tighter budget or larger size make the higher cost silica-sol process impractical.
Buod ng Proseso
Water-glass investment casting follows the general lost-wax procedure with a few differences in mold materials:
Wax Pattern at Tree Assembly.
A master pattern is produced (by injection molding, 3D pag print, or hand sculpting) and a pattern die/mold made if needed.
Wax replicas of the part are created from this master. Multiple wax patterns are then assembled onto a common sprue (forming a “tree”) using wax gates and feeders.
This wax cluster will form many castings in one pour. The wax surfaces are “dressed” to remove seams or defects, yielding an as-needled finish on each pattern.
Shell Building (keramik patong).
The wax assembly is repeatedly dipped into a refractory slurry of very fine sand or zircon flour suspended in a diluted sodium silicate solution.
Each dip coats the wax in a thin ceramic layer (often 0.5–1 mm) before stuccoing with coarser sand.
After draining excess slurry, a stucco layer (larger silica sand granules) is applied by pouring or fluidized bed to bond to the sticky slurry.
The cluster is then allowed to harden (often air-dried or low-heat cured). This coat-dry cycle is typically repeated 4–7 times to reach the necessary shell thickness (usually 5–15 mm total).
During this sequence, later coats use coarser and sometimes different refractories (e.g. fine silica first coats for detail, coarse quartz sand in backing layers) to maximize strength and permeability.
In water-glass processes, quartz/fused-silica sands and alumino-silicates are common refractories. The entire shell is finally dried thoroughly (sometimes in humidity-controlled ovens) to remove moisture.
Pag-aalis at pagpapaputok.
The hardened ceramic shell is dewaxed by melting the wax out of the mold.
Unlike silica-sol shells (which typically burn out wax in a burnout furnace or with flame), water-glass shells are often dipped into hot water or exposed to steam to melt the wax.
The purpose is to quickly clear the wax while minimizing shell stress (sodium silicate shells are stiffer when cold).
Pagkatapos ng pag-dewax, the shell is fired (sintered) at high temperature (often 800–1000 °C) to strengthen the ceramic and to burn out any remaining organics.
This also causes the sodium silicate binder to sinter and partially vitrify, forming a rigid, gas-permeable mold.
Metal pagbubuhos.
Molten metal is poured into the pre-heated shell in the usual manner. Because water-glass shells use conventional silica sands, their heat capacity and thermal conductivity are similar to sand molds.
The shell supports the metal until solidification (with minimal shrinkage cavities if risers are used).
Pag-alis at Pagtatapos ng Shell.
Sa sandaling matibay, the ceramic shell is removed by mechanical means (e.g. shot-blasting, vibration or hammering) to reveal the cast parts.
Residual quartz sand is cleaned off. The casting tree is cut apart, and gates and risers are trimmed.
Final pagtatapos ng may include grinding, CNC machining, at ibabaw ng paggamot as needed.
Because the initial shell finish is moderate, water-glass castings often require some surface grinding or machining, but less so than green-sand castings.
Napakahalaga, the water glass process differs from a silica-sol process mainly in binder and dewax method.
In water-glass casting, sosa silicate (alkali silicate) sets by drying and curing, whereas silica-sol (colloidal silica) shells harden primarily by gelation.
Dewaxing is performed with hot water (a wet dewax) instead of flame. These differences affect cycle time and quality.
Halimbawa na lang, wet-dewax is gentler on brittle shells, but it requires waste-water handling. Pati na rin, water-glass shells generally have lower thermal stability than zircon-containing silica-sol shells, as discussed below.
Sistema ng Binder
The binder in water-glass casting is sodium silicate solution (commonly Na₂O·nSiO₂). Chemically, water glass is highly alkaline (pH ~11–13) and made with a certain silica-to-soda ratio.
Typical formulations range from a 2:1 sa 3.3:1 SiO₂:Na₂O weight ratio (often expressed by module, e.g. M=2.0 means about 2.3 parts SiO₂ per Na₂O).
The ratio and solids content control key properties. Lower ratios (more Na₂O) give a more fluid slurry and faster set-on-drying, but also a more hygroscopic and lower-refractoriness binder.
Higher ratios (more SiO₂) increase heat resistance and lower pH.
Water glass is water-thin (viscosity similar to water) and cures by evaporation and mild heat. As it dries, it forms a rigid amorphous silicate glass network.
The binder is hygroscopic, so shells must be thoroughly dried before firing or exposure to humid air or water, or they can re-soften and degrade.
In service, residual moisture can lead to steam pockets or porosity if metal is poured too hot. The curing stage typically includes baking at 100–200 °C to harden the shell fully and drive off moisture.
Advantages of sodium silicate binders include their low cost, unlimited “shelf life”, at kadalian ng paggamit (no toxic solvents or acid catalysts).
They set by simple drying (or with a salt cure) and yield very stiff shells.
Gayunpaman, limitations exist: their high alkalinity can attack refractory grains or metal (especially aluminum, causing gas pickup), and their glassy nature gives lower high-temperature strength than silica-sol shells.
Sa pangkalahatan, water glass shells soften if heated above ~800–900 °C, so they suit steel/iron alloys but are marginal for very hot-casting alloys.
Sa kabila nito, sodium silicate remains a proven binder in the industry. It is one of three conventional binders (along with ethyl silicate and colloidal silica) commonly cited for investment mold making.
Mga Materyales sa Shell at Mga Pamamaraan sa Konstruksiyon
The shell for water-glass casting is built almost entirely from silica-based refractories. Sa pagsasanay, the primary materials are silica or quartz sand (fused or crystalline), possibly mixed with alumino-silicates.
Typical particle sizes for prime (ayos na ayos) coats might be 100–200 mesh (75–150 μm) to capture detail, while backup coats use coarser sand (e.g. 30–60 mesh).
Zircon is rarely used in water-glass shells (unlike silica-sol shells) due to cost – instead, cheaper silica sands are employed.
Finer alumina or titania flour can be added to improve thermal shock resistance, but the base is silica.
pH control is crucial in the slurry. The sodium silicate binder is very alkaline, so often a small amount of buffer or salt (like sodium bicarbonate) is added to adjust gel time and prevent immediate cure.
Manufacturers monitor the slurry pH (often around 11–12) and viscosity to ensure consistent coating thickness. Overly high alkalinity can cause the first coat to gel prematurely on the wax.
Sa pagsasanay, water-glass shells use 4 sa 7 coating layers (prime coat plus several stucco-backed coats).
Halimbawa na lang, an initial dip in a fine silica slurry is followed by stuccoing with fine quartz sand (this “prime coat” locks in pattern detail).
Subsequent coats use progressively coarser sands to build strength. Each coating must dry (often 1–2 hours at room temperature or faster in a low-heat oven) before the next coat.
The final shell thickness is usually on the order of 5–15 mm total.
During drying, temperature and humidity are carefully controlled – too rapid drying can crack the shell, while too slow drying can cause running or distortion.
Compared to silica-sol shells, water-glass shells tend to be strong but less refractory.
Fused silica layers give decent hot strength up to ~900 °C, but beyond that the sodium silicate glass network can begin to soften.
Sa kabilang banda, silica-sol shells often use zircon and alumina layers that remain stable above 1200 °C.
Sa madaling salita, silica-sol moulds can better withstand the higher pouring temperatures of superalloys, whereas water-glass shells are typically limited to steels and irons.
Paghahagis ng Mga Metal at Pagiging Tugma
Water-glass casting excels with common ferrous alloys. Typical steels include carbon bakal, mababa ang- and medium-alloy steels, heat-resistant hindi kinakalawang na asero, and manganese steels.
Cast irons (grey and ductile) are also commonly cast. These alloys can be poured in the 1400–1600 °C range without catastrophically damaging the silica shell (with proper heat schedules).
Sa katunayan, water-glass is especially popular for wear parts and heavy components made of steel, where the extra shell strength (compared to sand cast) and complexity pay off.
Water glass is less suited to reactive or light metals. Aluminum and magnesium alloys, halimbawa na lang, require very dry, clean shells.
Any moisture or soda in the shell can generate hydrogen porosity in aluminum or cause oxidation.
Titanium and other reactive alloys usually demand silica-sol or ceramic shell systems (or vacuum melting) because water glass shells do not have the required inertness or purity.
(Practically, lost-wax casting of titanium is done almost exclusively with refractory zircon/alumina-shell systems, not water glass.)
Kaya nga, metallurgical compatibility is a key consideration: water glass is chosen when the cast metal is compatible with silica (ferrous systems) and the process economy is needed.
In terms of metallurgy, water glass shells can influence casting quality.
Halimbawang, carbon steels may undergo slight carburization at the shell interface if dewaxed with acidified water, so neutral water is used.
Gas permeability of the ceramic helps vent hydrogen and gas; gayunpaman, any inadequate dewax or moisture can produce gas porosity.
Shrinkage porosity is managed via risers and vents as usual.
Sa pangkalahatan, water-glass castings behave metallurgically like other precision castings of the same metal – the shell chemistry has minimal alloying effect but can slightly alter surface decarburization.
Proper process controls (like vacuum or inert-atmosphere pouring for certain steels) may be applied as needed, but are independent of the binder type.
Katumpakan ng Dimensyon at Tapos na Ibabaw
Water glass investment castings achieve moderate precision. Dimensional mga tolerance are typically ISO CT7-CT9 for general dimensions. (For fine walls, tolerance may relax to CT9 or CT10.)
To put this in perspective, ISO CT7 on a 50 mm feature allows about ±0.10 mm deviation, whereas CT6 would be ±0.06 mm.
Sa pagsasanay, small parts and well-controlled processes can approach CT6-CT7,
but larger or more complex castings often are in the CT8-CT9 range.
This is comparable to fine sand casting tolerances.
Sa kabilang banda, high-end silica-sol castings can reach CT4-CT6 on small dimensions, so water glass is less accurate by about one tolerance grade.
Quality-conscious shops will specify the tolerances based on ISO 8062, often noting “CT8” as a baseline for water-glass processes.
Surface finish is likewise coarser than silica-sol but smoother than sand cast. Tipikal pagkamagaspang ng ibabaw for water-glass castings is on the order of Ra 6–12 μm (250–500 μin).
One foundry reported that water-glass castings reached roughly Ra = 12.5 μm in comparison tests. Sa kabilang banda, silica-sol parts may achieve Ra 3–6 μm.
The higher roughness of water glass is due to the larger grain sizes in the shell and the nature of the sodium-silicate binder.
Factors that affect the finish include slurry solids content, stucco grain size, shell thickness, and pattern quality.
Halimbawa na lang, finer prime-coats and additional prime layers can improve surface quality.
Gayunpaman gayunpaman, designers should expect a rougher initial surface: typical castings often need light grinding or machining to reach smoothness around Ra 3–6 μm for critical surfaces.
To manage accuracy, most shops use dimensional inspection (mga calipers, CMM, mga gauge) on first-parts and production samples.
Since the wax pattern and tree introduce some variability, careful layout and shrink compensation are needed.
The coefficients of thermal contraction for steel (tungkol sa 1.6 mm/m·100 °C) are used to scale patterns. Process documentation defines shrink factors and tolerances per ISO.
Kontrol ng Kalidad at Inspeksyon
Quality control in water-glass casting mirrors other foundry disciplines. Critical steps are inspected at multiple stages:
- Shell inspection: Before pouring, shells are examined for cracks, blisters, or incomplete coating.
Contractors often measure shell thickness with ultrasonic gauges and verify that each layer is uniform. Any delamination or pinholes can cause casting defects.
Containers of wet slurry are monitored for pH and solids; variations can produce weak shells. Dryer ovens are checked for even heat distribution. - Dimensional checks: After shakeout and finish-machining, castings are measured against design dimensions.
First-article parts typically undergo CMM inspection to verify critical dimensions to within the specified tolerance class (e.g. ISO CT8).
Simple gauge blocks or plug gauges are used for hole diameters. Because the tree pitch and wax shrinkage add small errors, it’s common to adjust pattern master dimensions if runout occurs. - Defect detection: Water-glass castings may suffer defects like gas porosity, mga inclusions, or shell fusion defects.
Common inspection methods include X-ray/radiography (to find internal cavities or inclusions), fluorescent penetrant (for surface cracks and porosity), and magnetic-particle testing (for ferrous parts).
Where appropriate, pressure testing or flow tests are applied. Pagsusuri ng metalurhiko (macro etch, micrographs) can be used during process development.
All testing should reference standards (e.g. ASTM E165 for penetrant, ASTM E446 for radiography) to define acceptance. - Process documentation: Strict traceability is maintained on water-glass casts. Records include slurry mix ratios, cure schedules, and furnace times.
Many foundries use in-process checklists (temperature logs for dewax ovens, humidity logs for drying rooms, and binder usage logs).
For high-reliability parts (e.g. mga bahagi ng aerospace), a full heat code and chemical/physical certification accompany the part.
ISO 9001 or Nadcap standards may govern documentation in critical industries.
Pangkalahatang, the control philosophy is to standardize every step so that any casting failure can be tracked back to its root cause (e.g. an unstable slurry or a missed drying cycle).
Mga pagsasaalang-alang sa ekonomiya
Water-glass lost-wax casting is valued for pagiging epektibo ng gastos in suitable applications. Key economic factors include material cost, paggawa ng trabaho, cycle time, and yield:
- Mga Materyal: Sodium silicate binder and quartz sand are inexpensive compared to colloidal silica and zircon.
Halimbawa na lang, sodium silicate solution may cost a few cents per kilogram, whereas colloidal silica binders cost an order of magnitude more.
The salts or accelerators used are minimal. Wax patterns (especially if 3D-printed) add cost, but yield is high.
There is some scrap ceramic waste (broken shell) but it can often be recycled as sand. Pangkalahatang, consumables are low-cost. - Labor and processing time: Building a water-glass shell is labor-intensive, requiring multiple dips and drying cycles.
Cycle times of 24–72 hours from wax tree to pour are typical (faster than high-temp silica-sol which can take longer cures).
The wet dewax step is longer (immersion vs open flame burn), but this is usually an overnight soak. Labor is needed for pattern prep, coating/stucco operations, and shakeout.
Sa kabila nito, the lower tooling costs and reduced machining often offset higher labor.
In a cost model, water glass can be competitive when part volumes exceed a few hundred per year, especially for heavy or complex parts that would be very expensive in sand or die casting. - Throughput: Single-purpose water-glass lines can run continuously, but each build (shell loading, Dewax, fire, pour, knock-out) handles only the parts on that tree.
Throughput is moderate; few hundreds of kilograms of castings per batch might be normal. Gayunpaman, automation exists for wax injection and shell spraying.
The limiting step is often dewaxed and firing, which can be batch ovens with defined loads. Effective scheduling (stacking trees) can improve utilization. - Yield and scrap: Because the process is precise, scrap rates can be low if controlled. Gayunpaman, any shell crack or metal leak-through yields a total loss of that casting.
Failures due to shell defects (e.g. post-dewax cracking) are minimized by tight process control.
Compared to sand casting, water-glass generally has higher yield since parts are easier to clean and nearly net-shape.
Compared to silica sol, yield is similar or slightly lower (silica-sol shells can be more forgiving of dewax issues).
A rough cost comparison might show that water-glass casting can be 50–70% cheaper per part than silica-sol casting for medium-precision steel parts,
due to lower material and tooling cost, albeit with modest loss of surface quality.
It is more expensive than cheap sand casting per unit, but because final parts need much less machining, ang total finished-part cost can be competitive.
Sa madaling salita, water-glass casting allows companies to shift cost from machine hours to process time,
which is often advantageous for parts that are complex or low-volume enough that dedicated tooling is not justified.
Mga Pang industriya na Aplikasyon
Water-glass investment casting finds its niche in heavy-duty and complex components across several industries. Notable applications include:
- Machinery and heavy equipment: Components for mining, langis & gas, and construction machinery often use water-glass casting.
Halimbawa na lang, mga gears, Mga pabahay ng bomba, Mga balbula, and impellers in these sectors benefit from the strength of steel and the geometric freedom of investment casting.
Water Glass Casting Stainless Steel Valve Pipe Fitting - Agricultural parts: Parts like tractor housings, plow components, and heavy farm equipment linkages are made this way.
The ability to cast ductile iron or low-alloy steel shapes (e.g. tiller parts, seed drilling plates) Ang pagkakaroon ng masalimuot na mga profile ay isang pangunahing bentahe. - Automotive: Bagama't hindi karaniwan para sa mga bahagi ng kotse na ginawa ng masa, Ang paghahagis ng salamin ng tubig ay ginagamit sa mga bahagi ng sasakyan o trak na may mababang dami (e.g. Maliit na batch ng manibela buko, mabigat na suspensyon ng mga braso, Mga bahagi ng preno para sa mga espesyal na sasakyan).
Ang katumpakan nito ay lumampas sa paghahagis ng buhangin para sa mga kritikal na bahagi ng akma, Gayunpaman, nananatiling epektibo ang gastos para sa katamtamang pagtakbo. - Mga pang-industriya na balbula at bomba: Mga balbula ng cast iron at bakal, Mga Katawan ng Bomba, Kadalasan ay nagmumula sa mga hulma ng pamumuhunan ang mga flanges na salamin ng tubig.
Ang mga bahaging ito ay nangangailangan ng kumplikadong panloob na daanan at isang mahusay na pagtatapos sa ibabaw (Upang maiwasan ang pagtagas) - water-glass paghahagis yields valves handa na para sa machining nang walang cores. - Konstruksiyon at arkitektura castings: Paminsan-minsan, pandekorasyon o istruktura na mga elemento ng bakal / bakal (tulad ng mga flanges, hardware na hardware, O Mga Suporta sa Mga Suporta) Alisin ang taba mula sa tiyan sa pamamagitan ng tubig.
Ang proseso ay maaaring makuha ang pinong artistikong mga detalye habang gumagamit ng abot-kayang buhangin, Ginagawa itong angkop para sa mga espesyal na castings (e.g. tanso na kapalit sa mga elemento ng arkitektura). - Mga bahagi ng malayo sa pampang at maritime: Tulad ng nabanggit ng mga mapagkukunan ng industriya, Mga Bahagi para sa Mga Trailer, mga kreyn, at ginagamit ng mga marine rig ang pamamaraang ito para sa tibay sa malupit na kapaligiran.
Pangkalahatang, Pinili ang paghahagis ng baso ng tubig sa mga industriya na nangangailangan ng Matibay na ferrous castings na may katamtamang detalye sa makatwirang gastos.
Nakikipagkumpitensya ito sa paghahagis ng buhangin kapag kinakailangan ang mas mataas na katumpakan o detalye ng hugis ng net, at nakikipagkumpitensya ito sa paghahagis ng pamumuhunan sa silica-sol kapag ang malaking sukat o mga hadlang sa badyet ay ginagawang masyadong mahal ang huli.
Pagsusuri ng Comparative
Kung ikukumpara sa iba pang mga pamamaraan ng paghahagis, Ang paghahagis ng pamumuhunan sa baso ng tubig ay sumasakop sa isang gitnang lupa:
Baso ng Tubig kumpara Paghahagis ng Pamumuhunan ng Silica-Sol:
Silica-sol (colloidal-silica binder na may harina ng zircon) Lumikha ng Pinakamahusay na Detalye, Pinakamahusay na Pagtatapos sa Ibabaw (Ra kasing baba ng 3-6 μm), at mas mahigpit na tolerances (ISO CT4-CT6).
Gayunpaman, ito nga pala mas mahal pa: Ang mga solusyon sa silica sol at zircon sands ay nagkakahalaga ng mas malaki, at ang proseso ay nangangailangan ng pagkasunog ng apoy at mas mataas na temperatura ng pagpapaputok.
Paghahagis ng baso ng tubig, sa pamamagitan ng kaibahan, ay may mas magaspang na pagtatapos (~Ra 6–12 μm) at mas malawak na tolerances (CT6-CT9), ngunit gumagamit ng murang materyales at mas simpleng dewax.
Ang mga shell ng baso ng tubig ay may posibilidad ding maging mas malakas sa paghawak bago ibuhos (Ang mga ito ay napaka-matigas pagkatapos ng pagpapatayo) at maaaring maging mas makapal, na nakikinabang sa mabigat na pagbuhos.
Sa buod, Silica-Sol ay pinili para sa mataas na katumpakan, maliliit na bahagi; Pinili ang baso ng tubig para sa mas malaki, Matitigas na bahagi kung saan maaaring isakripisyo ang pagtatapos ng ibabaw.
Paghahagis ng Pamumuhunan sa Salamin ng Tubig mga bes Buhangin Paghahagis:
Buhangin paghahagis (berdeng buhangin o kemikal na nakadikit) Ito ang pinakamababang gastos, Pinaka-nababaluktot na paggawa ng amag para sa malalaking bahagi.
Gayunpaman, Ang mga cast ng buhangin ay may napaka-magaspang na ibabaw (Ra > 25 M, madalas na 50-100 μm) at maluwag na tolerances (ISO CT11 o mas masahol pa).
Ang paghahagis ng tubig-salamin ay nagbibigay ng makabuluhang mas mahusay na ibabaw at katumpakan (Tulad ng nabanggit sa itaas) sa mas mataas na gastos.
Kung ang isang bahagi ng buhangin ay nangangailangan ng malawak na machining o pag-aayos (tulad ng hinang sa mga core), Maaaring mas mura ang paggamit ng baso ng tubig.
Pati na rin, ilang mga kumplikadong hugis (manipis na pader, panloob na mga voids) Mahirap o imposible sa buhangin na walang mga core; Madaling makabuo ng mga ganitong hugis ang baso ng tubig.
Ang trade-off ay na buhangin paghahagis scales mas mahusay para sa lubhang mataas na dami (Mga kagamitan sa pag-aalaga o pag-aayos ng mga bulate na maaaring magamit nang maraming beses),
Samantalang ang tubig ay limitado sa paligid 150 Kg bawat amag at nangangailangan ng multi-araw na pag-ikot.
Lakas ng Shell at Pag-uugali ng Thermal:
Ang mga shell ng baso ng tubig ay binubuo ng mga fused-silica layer, na kung saan ay bahagyang mas mababa refractory kaysa sa zircon o alumina layer na madalas na ginagamit sa silica-sol shells.
Nangangahulugan ito na ang mga shell ng baso ng tubig ay karaniwang may mas mababang maximum na temperatura ng serbisyo at maaaring payagan ang mas maraming reaksyon ng metal-shell sa napakainit na pagbuhos.
Sa pagsasanay, bagaman, Ang parehong mga pamamaraan ay gumagawa ng mga shell na madaling makatiis ng mga temperatura ng bakal / bakal na ibuhos.
Sa mga tuntunin ng lakas, Ang parehong silica-sol at water-glass shell ay matigas pagkatapos ng pagpapaputok, Ngunit ang silica-sol ay maaaring mapanatili ang integridad ng istruktura sa mas mataas na temperatura.
Pinakamahusay na Mga Kaso ng Paggamit:
Pagbubuod ng mga pinakamahusay na gamit, Ang pag-aayos ng baso ng tubig ay perpekto para sa katamtaman hanggang malalaking mga bahagi ng bakal / bakal kung saan ang mataas na katumpakan ay hindi kritikal,
Tulad ng mga pabahay ng bomba, Mga blangko ng gear, mabibigat na bahagi ng makinarya, at anumang bahagi kung saan ang mga tampok na cast-on ay nagse-save ng hinang.
Ang Silica-Sol ay Pinakamainam para sa maliit hanggang katamtamang mataas na katumpakan na mga bahagi (mga bahagi ng aerospace, mga alahas, medikal na implants, Maliit na hindi kinakalawang na mga bahagi).
Panalo ang paghahagis ng berdeng buhangin para sa napakalaking mabibigat na bahagi o napakalaking dami kung saan hindi na kailangan ng mahigpit na detalye (e.g. malalaking pabahay, mga bloke ng engine, Mga casing ng bomba nang maramihan).
Ang talahanayan sa ibaba ay nagtatampok ng ilang mga paghahambing na sukatan:
- Pagkamagaspang ng Ibabaw (tipikal na Ra): Silica-sol ~ 3-6 μm; baso ng tubig ~ 6-12 μm; berdeng buhangin >25 M.
- Dimensional na pagpapaubaya: Silica-sol ISO CT4-CT6; baso ng tubig ~ CT6-CT9; berdeng buhangin CT11-CT12 (napaka maluwag).
- Gastos sa Materyal: Mababa para sa buhangin, katamtaman para sa baso ng tubig, mataas para sa silica-sol. Ang Sodium Silicate Binder ay Napaka Mura, Samantalang ang colloidal silica binder ay mahal.
- Lakas ng Shell: Mabuti para sa silica-sol sa mataas na T, katamtaman para sa baso ng tubig. Zircon / alumina shells (silica-sol) Magkaroon ng mas mataas na refractoriness.
- Scale ng Produksyon: Ang baso ng tubig ay angkop sa maliit hanggang katamtamang dami (Dose-dosenang hanggang libu-libo bawat taon), lalo na kapag mabigat ang mga bahagi. Ang silica-sol ay nababagay sa maliliit / katumpakan na tumatakbo; Ang buhangin ay angkop sa malalaking dami.
Pangkalahatang, Ang paghahagis ng baso ng tubig ay nagbibigay ng tulay sa isang puwang: ito ay nag aalok ng Mas mahusay na kontrol at tapusin kaysa sa paghahagis ng buhangin, pero Mas mababang gastos kaysa sa silica-sol.
Kapag ang mga pangangailangan sa disenyo ay katamtaman at ang mga badyet ay limitado, Ito ay kadalasang ang pinaka-matipid na pamamaraan ng katumpakan.
Pangwakas na Salita
Baso ng tubig (sosa silicate) Ang paghahagis ng pamumuhunan ay isang matipid sa gastos katumpakan paghahagis Proseso na na-optimize para sa ferrous, kumplikadong mga bahagi.
Sa pamamagitan ng paggamit ng murang binders at sands, Pinapayagan nito ang mga tagagawa na makamit ang malapit-net-hugis na mga bahagi ng bakal at bakal na may makatwirang mga tolerance (ISO CT7-CT9) at mga pagtatapos (Ra ≈6–12 μm) Sa isang maliit na bahagi ng gastos ng silica-sol casting.
Ang kalakasan ng proseso ay ang materyal na ekonomiya nito, malakas na katigasan ng shell, at kakayahang makabuo ng mga kumplikadong geometries nang walang pagbagsak ng core.
Ang mga pangunahing limitasyon nito ay isang mas magaspang na pagtatapos sa ibabaw at mas mababang katatagan ng mataas na temperatura, Na naglilimita sa katamtamang katumpakan, mabigat na mga aplikasyon.
Looking forward, Ang paghahagis ng baso ng tubig ay nananatiling may kaugnayan para sa mga application tulad ng makinarya, Mga subassemblies ng sasakyan,
kagamitan sa agrikultura at konstruksiyon, at anumang mga bahagi na nakikinabang mula sa isang mahusay na kompromiso ng detalye at gastos.
Patuloy na pagpapabuti (tulad ng na-optimize na mga pormulasyon ng silicate at awtomatikong patong ng shell) maaaring itulak ang katumpakan nito nang bahagyang mas mataas.
Gayunpaman, Dapat maingat na itugma ng mga inhinyero ang mga bahagi sa proseso: gumamit ng baso ng tubig kapag Bakal / bakal kumplikado at ekonomiya mangibabaw ng mga kinakailangan,
silica-sol kapag Ultra-pinong detalye o mga espesyal na haluang metal ay kinakailangan, at buhangin kapag manipis na dami o laki Pagpawalang-bisa ng katumpakan.
Pangkalahatang, Bulate Ba Kamo Eto nA San Ka Pa kung paano mapupuksa ang mga halamang-, Mahusay na nauunawaan ang pamamaraan.
Ang patuloy na paggamit nito ay hinihimok ng pandaigdigang pangangailangan para sa matatag na, masalimuot na hugis na mga bahagi ng metal sa katamtamang tolerance at mapagkumpitensyang gastos.
Ang tamang aplikasyon ng mga kontrol sa kimika at proseso nito - at masusing inspeksyon - ay nagbubunga ng pare-pareho, Mataas na kalidad na castings para sa isang malawak na hanay ng mga pang-industriya na pangangailangan.
DEZE Ito ang perpektong pagpipilian para sa iyong mga pangangailangan sa pagmamanupaktura kung kailangan mo ng mataas na kalidad water glass investment casting Mga Serbisyo.
