This Research is to Study the Development of 6k White Gold Low Alloys Metal for Jewelry Production The Optimum Conditions for Casting Jewelry and Jewelry were Investigated. The Results of the Experiments Show that the Chemical Composition of the 8k White Gold Low Alloys is Slightly Different when Compared with XRF (X-ray Fluorescence Spectrometers) Pre-and Post-Melting Quantities The Heat of the Test Specimen was found to be 33.33%Au+50.67%Ag+10%Cu+5%Zn+1%Sn33.33%Au+50.67% Ag+8% Cu+7%Zn+1%Sn and 33.33%Au+50.67%Ag+8%Cu+8%Zn+0%Sn It is Found that the Heat from the Beginning to the Level of Change before the Liquid is used the Average Temperature of 458.9 – 326.3 Degrees Celsius Respectively 33.33%Au+50.67%Ag+8%Cu+7%Zn+1%Sn It is the Formula that Gives the Lowest Value of Liquid State Change from 326.3 Degrees Celsius to the Best Value of this Experiment. Suitable for use in the Manufacture of Jewelry due to its Melting Ability for Molding. Melting for Molding and Formed by Hand. The Amount of Zinc(Zn) may be an Important Factor in the Variation which is Directly Proportional to the Maximum Increase in the Final order of 7 Percent

This Research is a Development of 8k White Gold low Alloy Metal Components for Jewelry Pieces. By Study and Analyze the Influence of Silver Alloy Gold Alloy Bronze Alloy Zinc Alloy and Tin Alloy. Which Affect Microstructure and Mechanical Properties. (The Different of Color Scales) And Resistance Behavior of Lowered 8k White Gold Alloy in Varies Ratio. The Results Showed that Tests and Analysis to Find the Quantities of Elements has found out that Chemical Components of 8k White Gold Low Alloy Metal had a Little Different Quantities when Compared Between Before and After Centrifugal Casting Process. The Tests and Analysis Results of Mechanical Properties of Test Pieces Showed that the Hardness and Tensile Strength of 8k White Gold Low Alloy Metal with Mixture of 33.33%Au+50.67%Ag+10%Cu+5%Zn+1%Sn had Minimum Ultimate Tensile Strength Equal 0.54 kN/mm2 Minimum Elongation Percentage of 55% and Maximum Hardness of 137.0 HV. The Test Results also Show that the Mechanical Properties of the Material are Brittle Material. When Perform a Forming Process the Pieces will be Easily Broken which was Meant that the Forming Process would be Difficult. But The Color Level of the Test Pieces at this Composite Ratio had the Best Metal Color Level. The Brightness L * = 74.87 was a * = -0.89 b * = 13.74 and the Value of ΔE with the Lowest Color Difference Level of 1.35. Compared to other Varies Ratio. It Showed that 8k White Gold Low Alloy Metal Test Pieces were Very Green and Came out Slightly Yellow Compared to the Blue Line that Approached the Standard Line. These Properties were the Physical Properties Required in 8k White Gold Low Alloy Metal Jewelry Pieces Production. Also there were the Results of 8k White Gold Low Alloy Metal in Two Formulas 8k 33.33%Au+50.67%Ag +8%Cu+7%Zn+1%Sn 33.33%Au+50.67%Ag+8%Cu+8%Zn+0%Sn. These Formulas had Tensile Strength in the Range of 1.10 0.60 kN /mm2 Elongation Percentage in the Range of 70 61% and Hardness of 115.6 123.3HV Respectively. The Results of the Mechanical Properties Test of the Test Pieces Showed that 8k White Gold Low Alloy Metal 33.33% Au+50.67%Ag+8%Cu+7%Zn+1%Sn has Similar Tensile Strength but Maximum Elongation Percentage of 70% and Minimum Hardness of 115.6HV. Which was Suitable for Forming Because of good Ductility and Stretchness Properties (Ductile Material). Forming would be Easy. These were Good Mechanical Properties for Forming Precious Metals.

This research is a study of the optimum heat temperature for baking sintered castings for burnout removal of EC 500 type ash wax from cast mortar. Improving jewelry casting process to reduce waste from silver jewelry production process. By studying the temperature of the mortar. To burn remove wax from the mortar and clean the gaps. Then try to bring silver water instead of metal casting. The results of a baked casing study using the EC500 housing prototype from the study showed that the EC500 wax material is melted from all solids to ash wax by heating at 850 ° C to burn. Remove ash wax which makes the cavity clean. When the casting was casted with 925 sterling silver the most complete workpiece after the improvement of the waste jewelry casting process was found to be 1 piece 1 percent 99 pieces or 99 percent.

After a propeller shaft was damaged from chloride in sea water it has been fixed by MAG welding process with flux cored wire. Its service life after welded depends on the corrosion resistance of the weld metal. This research aimed to compare the corrosion resistance of two different weld metals between X111-T5-K4 and E71T-1CH8/T/9M-D flux core wire. The test specimens were prepared according to the ASTM G1-103 standard and tested by salt spray test conforming to the ASTM B 117 standard. The result of the test showed that the corrosion rate of the weld metal using X111-T5-K4 flux cored wire is lower than the weld metal of E71T-1CH8/T/9M-D flux cored wire which was 0.21 and 0.32 mm2/hr. respectively. The mass loss at 24 hours of E71T-1CH8/T/9M-D X111-T5-K4 flux core wire were 0.32 and 0.48 grams respectively. Therefore enhancing the service life of propeller shaft from chloride corrosion should use X111-T5-K4 flux core as weld metal

The objective of this research is to study how rotation speeds affect mechanical properties with friction welding between semi-solid metal 7075 aluminum alloys and semi-solid metal 356 aluminum alloys. The factor of interest is rotation speeds with different conditions at 800 1000 1200 1400 and 1600 rpm respectively. 1.8 millimeter for burn of length 30 seconds for welding time and clockwise rotation are set as a control constant condition for the entire experiment. After friction welding we found that different rotation speeds significantly affected mechanical properties of these alloys. At rotation speed 1400 rpm the maximum tensile strength is 122.24 MPa and the maximum hardness in welded zone is 140.5 HV. The microstructure size is 2.250 µm long and 2.144 µm wide. Its size in welded zone is practically small because of friction force. Moreover this friction force causes the mixture of MgZn2 and Mg2Si in welded zone.