מתכת חצי אצילה לבנה - PALACAST
הרכב המתכת :
Ag = 59%
Pd = 25%
Cu = 14%
הוראות עבודה:
WAXING AND SPRUING-Direct spruing:The direct technique may be used for spruing single units.Use a 2.6 mm sprue
Indirect Spruing:The indirect technique is always preferd for spruing bridges,multiple units, and single units.With bridges use 2.6mm feed sprues 1.6mm long.For multiple units use the same size feed sprue.Attach the length of a 3.3mm runner bar and connect the runner by two 4.1mm indirecr sprues to the crucible former
INVESTING AND BURNOUT-Technique:Invest the pattern in non-graphite,phosphate bonded investment.Follow the investment manufacturer's instruction
Place the ring in a cold furnace,run it directly to 704C,and heat soak for one hour .Or, place the ring in preheated 427C furnace for 15 minutes.Raise the temaprture of the furnace to 704C and let it heat soak at this temaprture for approximately one hour
If there is ny plastic in the mold, a two-stage burnout is required.Place the ring in a cold furnace and raise the temparture at a rate of 6C pre minute to 315C .Heat soak at this temparture for 30 minutes.Raise the temparture to the normal burnout temparture at a normal rate and heat soak.
Allow additional burnout time for large rings,and very thin patterns
CASTING-Technique:Use oxygen, at approximately 10 psi, combined with natural gas.If you use propane or butane,set the oxygen pressure at about 5 psi
Take an extra wind on the casting machine.Use a 1:1 ratio of old ally to new alloy.Preheat the crucible,melt the button and add a oral type flux.Then add a new metal ingots to the melt.Seat the ring in the casting machine.Continue heating the alloy until it spins,then cast
HEAT TREATMENT-Technique: To anneal (soften) the alloy,s place the casting in a furnace at 704C and hold it there for 15 minutes.Then quench the casting in water
To harden the alloy, first anneal it as described above.After quenching,d place the casting in a furnace at 400C for 15 minutes.Then remove the casting and allow it to bench cool
RECOMMENDED PORCELAIN-Vita,Ceramco 2 silver.Ceramco 3,Caeramco 4,Vintage opal,Liiobond
Synspar,Excelco,Ivoclar and Willceram porcelains