Technical Chart

Basic Alloy, Red Gold Color 10-14-18k Page 1/2

Alloyed to 18K Red CEILab Color Coordinates [L: 81.7 a: 8.7 b: 15.2 c: 17.5]

Product Description Recommended Applications

Alloy with deep red color. The presence of grain refiners As far as mechanical working is concerned, 104401 can and this alloy’s high grade of deformability makes 104401 be considered as a universal alloy suitable for all an extremely versatile alloy for use in mechanical applications of plastic deformation. Suitable for torch working and lost-wax casting. This alloy’s small crystal melting and continuous casting machines, 104401 is used grain size makes it particularly suited for the lost-wax principally for stamping, wire and tubing. 104401 is also casting of designs that require subsequent steps of plastic used regularly for lost-wax casting and is particularly deformation. The deep red color that is obtained from suited to closed systems (presence of vacuum or inert 104401 makes it ideal for use in combination with white atmosphere) offering excellent performance where, after and yellow-gold pieces in two-color and three-color lost-wax casting, particular designs require subsequent jewelry designs. steps of plastic deformation.

Physical-chemical Properties Mechanical Characteristics for 18K

Approximate Composition of Master Alloy Tensile strength (Rm) [N/mm2] 531

Zn 2.0% Ag 6.0% Cu 92.0% Yield strength (Rp0.2) [N/mm2] 378

Elongation (A) [%] 29 Values below are for 18K made with this master alloy. Temperatures (ºC) Density (g/cm3) 14.7 “As cast” hardness [HV 0.2] 187

Solidus 905 Hardness after 70% red. [HV 0.2] 289 Liquidus 920 Hardness after annealing [HV 0.2] 182 Range 15 Hardness after age-hardening [HV 0.2] 336 General Characteristics Workability Excellent

“As cast” grain size [µm] 60 I1 153

I2 5 I3 29

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Crystal grain structure (500x) Age-hardening temperature profile (90 minutes)

Instructions for use

Casting Graining temperature (ºC) 1040 ______Casting temperatures

Size of objects Metal casting (ºC) Flask (ºC)

Thin from 0.2 to 0.5mm 1050-1020 660-720 Medium from 0.5 to 1.2mm 1020-1000 580-650 Thick > 1.2mm 1000-980 460-600

Flask quenching Quench directly in water. Pickling Dip items in Rio Pickle cleaning solution for 20-30 minutes or in a 10% sulfuric acid solution for 5 minutes. Recommended age-hardening treatment 250º C 90 minutes

Mechanical Working Pouring temperature (ºC) 1000-1035 Recommended thickness reduction 70.0% ______Annealing treatment

Sheet thickness Temperature (ºC) Minutes 5 – 14mm 620-660 35 1 – 5mm 620-660 30 0.2 – 1mm 620-660 25

Quenching Quench directly in 50% water and 50% alcohol solution or only in water.

Recommended age-hardening treatment 250º C 90 minutes

Notes

From a metallurgical point of view, the characteristics of the composition of 104401 can, in some cases, cause changes to the crystal grain structure of the alloyed metal, leading to worsening of the mechanical properties. This can happen when the gold alloyed with 104401 is heated to temperatures in the range of 550-650º C and then left to cool slowly, e.g., air cooling. Similar changes can occur during bench working processes, e.g., torch soldering. In order to avoid problems of brittleness of this type, whenever gold alloyed with 104401 is heated, the material should be quenched immediately in water.

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