Ika Kartika

Characteristics of Mg-Ca-Zn Alloy Metallic Foam Based on Mg-Zn-CaH2 System

Mg-Ca-Zn alloy metallic foam has been recently recognized as biodegradable implant. In this present work, the characteristics of Mg-Ca-Zn alloy metallic foam which made by foaming of powder compact based on Mg-Zn-CaH2 system were investigated. Mg-Zn-CaH2 powder with nominal compositions of 97.5 weight % Mg, 2 weight % Zn, 0.5 weight % CaH2 and 96.8 weight % Mg, 2 weight % Zn, 1.2 weight % CaH2 were prepared by dry milling process for 6 h and characterized by differential thermal analysis (DTA). The prepared powders are pressed for 6.5MPa at room temperature and sintered for 2 h at various temperatures of 350 °C and 600 °C. The alloys were analyzed by x-ray diffraction and scanning electron microscope (SEM). The results indicated that addition of calcium hydride as blowing agent affects phase formation of Mg2Ca and Mg2Zn3, sintering temperature and grain refining of Mg-Ca-Zn alloy.

The synthesis and characterization of Mg-Zn-Ca alloy by powder metallurgy process

Known for its biodegradation and biocompatible properties, magnesium alloys have gained many interests to be researched as implant material. In this study, Mg-3Zn-1Ca, Mg-29Zn-1Ca, and Mg-53Zn-4.3Ca (in wt%) were synthesized by means of powder metallurgy method. The compression strength and corrosion resistance of magnesium alloy were thoroughly examined. The microstructures of the alloy were characterized using optical microscopy, Scanning Electron Microscope, and also X-ray diffraction analysis. The corrosion resistance were evaluated using electrochemical analysis. The result indicated that Mg- Zn- Ca alloy could be synthesized using powder metallurgy method. This study showed that Mg-29Zn-1Ca would make the highest mechanical strength up to 159.81 MPa. Strengthening mechanism can be explained by precipitation hardening and grain refinement mechanism. Phase analysis had shown the formation of α Mg, MgO, and intermetallic phases: Mg2Zn11 and also Ca2Mg6Zn3. However, when the composition of Zn reach 53% ...

INFLUENCE OF CARBON AND NITROGEN ADDITION ON THE CORROSION RESISTANCE OF Co-28Cr-6Mo-0,8Si-0,8Mn-0,4Fe-0,2Ni ALLOYS

Cobalt alloys is one of the implant materials that is used in orthopedic and dentistry, because of its biocompatibility, good mechanical properties, and high corrosion resistance. The mechanical properties and corrosion resistance can be enhanced by thermomechanical treatment and addition of alloying element. Carbon and nitrogen were added to enhance mechanical properties and high corrosion resistance. Effect of carbon variation and nitrogen to the corrosion resistance in Co-Cr-Mo (CCM) alloys were measured by corrosion measurement system (CMS) device in Hank’s Solutions after thermomechanical treatment process. Corrosion rate of Co-Cr-Mo alloys with carbon variation dropped to 5.8 x 10 -4 mmpy and 5.2 x 10 -4 mmpy with carbon variation and nitrogen. Decreasing corrosion rate indicated that the corrosion resistance of alloys is increased with the addition of carbon and nitrogen.

The effect of thermal pre-treatment of titanium hydride (TiH2) powder in argon condition

Titanium hydride (TiH2) powders are used to enhance the foaming process in the formation of a highly porous metallic material with a cellular structure. But, the low temperature of hydrogen release is one of its problems. The present study, different thermal pre-treatment temperatures were employed to investigate the decomposition behavior of TiH2 to retard or delay a hydrogen gas release process during foaming. As a foaming agent, TiH2 was subjected to various heat treatments prior at 450 and 500°C during 2 hours in argon condition. To study the formation mechanism, the thermal behavior of titanium hydride and hydrogen release are investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The morphology of pre-treated titanium hydride powders were examined using Scanning Electron Microscope (SEM) while unsure mapping and elemental composition of the pre-treated powders processed by Energy Dispersive Spectroscopy (EDS). To study the phase formation was characterized by X-ray...

Preparation and characterization of porous Mg-Zn-Ca alloy by space holder technique

Magnesium had been recently researched as a future biodegradable implant material. In the recent study, porous Mg-Zn-Ca alloys were developed using space holder technique in powder metallurgy process. Carbamide (10-20%wt) was added into Mg-6Zn-1Ca (in wt%) alloy system as a space holder to create porous structure material. Sintering process was done in a tube furnace under Argon atmosphere in 610 °C for 5 hours. Porous structure of the resulted alloy was examined using Scanning Electron Microscope (SEM), while the phase formation was characterized by X-ray diffraction analysis (XRD). Further, mechanical properties of porous Mg-Zn-Ca alloy was examined through compression testing. Microstructure characterization showed higher content of Carbamide in the alloy would give different type of pores. However, compression test showed that mechanical properties of Mg-Zn-Ca alloy would decrease significantly when higher content of carbamide was added.

Study of sintering on Mg-Zn-Ca alloy system

Magnesium and its alloy have gained a lot of interest to be used in biomedical application due to its biodegradable and biocompatible properties. In this study, sintering process in powder metallurgy was chosen to fabricatenonporous Mg-6Zn-1Ca (in wt%) alloy and porous Mg-6Zn-1Ca-10 Carbamide alloy. For creating porous alloy, carbamide (CO(NH2)2 was added to alloy system as the space holder to create porous structure material. Effect of the space holder addition and sintering temperature on porosity, phase formation, mechanical properties, and corrosion properties was observed. Sintering process was done in a tube furnace under Argon atmosphere in for 5 hours. The heat treatment was done in two steps; heated up at 250 °C for 4 hours to decompose spacer particle, followed by heated up at 580 °C or 630 °C for 5 hours. The porous structure of the resulted alloys was examined using Scanning Electron Microscope (SEM), while the phase formation was characterized by X-ray diffraction (XRD) analysis. Mechanical properties were examined using compression testing. From this study, increasing sintering temperature up to 630 °C reduced the mechanical properties of Mg-Zn-Ca alloy.Magnesium and its alloy have gained a lot of interest to be used in biomedical application due to its biodegradable and biocompatible properties. In this study, sintering process in powder metallurgy was chosen to fabricatenonporous Mg-6Zn-1Ca (in wt%) alloy and porous Mg-6Zn-1Ca-10 Carbamide alloy. For creating porous alloy, carbamide (CO(NH2)2 was added to alloy system as the space holder to create porous structure material. Effect of the space holder addition and sintering temperature on porosity, phase formation, mechanical properties, and corrosion properties was observed. Sintering process was done in a tube furnace under Argon atmosphere in for 5 hours. The heat treatment was done in two steps; heated up at 250 °C for 4 hours to decompose spacer particle, followed by heated up at 580 °C or 630 °C for 5 hours. The porous structure of the resulted alloys was examined using Scanning Electron Microscope (SEM), while the phase formation was characterized by X-ray diffraction (XRD) analysis. Mechanical p...

PENGARUH VARIASI BERAT FOAMING AGENT CaH2 TERHADAP KARAKTERISTIK PADUAN Mg-Ca-Zn METAL SELULAR BERBASIS SISTEM Mg-Zn-CaH2

THE EFFECTS OF FOAMING AGENT CONTENT CaH2 ON THE CHARACTERISTIC OF METAL CELLULAR Mg-Ca-Zn ALLOYS BASED ON Mg-Zn-CaH2 SYSTEM. In this study, cellular metal with the open-cell structure of Mg-Ca-Zn alloy based on Mg-CaH2-Zn system was prepared and investigated. The addition of CaH2 was intended to trigger the release of hydrogen gas from CaH2 of the alloy powder particles so as to encourage the formation of pores. Alloy composition was selected by -2% by weight Mg Zn 1.2% by weight of CaH2; and Mg -2 wt% Zn 10% by weight of CaH2. The results of the alloy powder after milling and compacting were tested by Differential Thermal Analysis (DTA), while the results of sintered green-compacts were characterized by XRD (X-ray diffraction) and microstructure observation using SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy). From the analysis using XRD, the process of mechanically mixing powders of Mg-Ca-Zn-Mg CaH2 produced elemental phase of Zn phase, Mg phase (HCP) and binary phase of Mg2Ca besides the ternary Mg-Ca-Zn.

Preparation and characterization of coating sodium trisilicate (Na2O.nSiO2) at calcium carbonate (CaCO3) for blowing agent in Mg alloy foam

The role of blowing agent in the manufacture of porous metal alloys is very important to produce the desired pore. The thermal stability and speed of foam formation have an effect on the resulting pore structure. In porous metal alloys, uniformity of size and pore deployment are the main determinants of the resulting alloys. The coating process of calcium carbonate (CaCO3) has been done using Sodium trisilicate solution by sol-gel method. Foaming agent was pretreated by coating SiO2 passive layer on the surface of CaCO3. This coating aims to produce a more stable blowing agent so that the foaming process can produce a more uniform pore size. The microstructure of the SiO2 passive was observed using Scanning Electron Microscope (SEM) equipped by Energy Dispersive X-Ray Spectrometer (EDS) mapping. The results showed coating CaCO3 using sodium trisilicate was successfully done creating a passive layer of SiO2 on the surface of CaCO3. By the coating process, the thermal stability of coated CaCO3 increased compared to uncoated CaCO3.The role of blowing agent in the manufacture of porous metal alloys is very important to produce the desired pore. The thermal stability and speed of foam formation have an effect on the resulting pore structure. In porous metal alloys, uniformity of size and pore deployment are the main determinants of the resulting alloys. The coating process of calcium carbonate (CaCO3) has been done using Sodium trisilicate solution by sol-gel method. Foaming agent was pretreated by coating SiO2 passive layer on the surface of CaCO3. This coating aims to produce a more stable blowing agent so that the foaming process can produce a more uniform pore size. The microstructure of the SiO2 passive was observed using Scanning Electron Microscope (SEM) equipped by Energy Dispersive X-Ray Spectrometer (EDS) mapping. The results showed coating CaCO3 using sodium trisilicate was successfully done creating a passive layer of SiO2 on the surface of CaCO3. By the coating process, the thermal stability of coated CaCO3 increased com...

Powder metallurgy preparation of Mg-Ca alloy for biodegradable implant application

Magnesium and its alloys is a promising candidate for implant application especially due to its biodegradability. In this study, Mg-7Ca alloys (in weight %) were processed by powder metallurgy from pure magnesium powder and calcium granule. Milling process was done in a shaker mill using stainless steel balls in various milling time (3, 5, and 8 hours) followed by compaction and sintering process. Different sintering temperatures were used (450°C and 550°C) to examine the effect of sintering temperature on mechanical properties and corrosion resistance. Microstructure evaluation was characterized by X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. Mechanical properties and corrosion behavior were examined through hardness testing and electrochemical testing in Hanks solution (simulation body fluid). In this report, a prolonged milling time reduced particle size and later affected mechanical properties of Mg alloy. Meanwhile, the phase analysis showed that α Mg, Mg2Ca, MgO phases were formed after the sintering process. Further, this study showed that Mg-Ca alloy with different powder metallurgy process would have different corrosion rate although there were no difference of Ca content in the alloy.

Processing of porous Mg-Zn-Ca alloy via powder metallurgy

Mg-Zn-Ca alloy is one of magnesium alloys that has been investigated for its potential in metal foam implant application. In this study, porous Mg-Zn-Ca alloy was prepared by powder metallurgy method, comprising of green compact fabrication and its sintering process. Calcium hydride (CaH2) was added as a foaming agent. The composition of Mg-Zn-Ca alloy was varied (1-30%wt CaH2, and 1 variation with 9%wt Ca addition; while Zn constant) to study the effect of foaming agent and calcium addition on phase formation and structural properties of Porous Mg alloy. Sintering process was done in a tube furnace under argon atmosphere in 520°C for 2 hours. The as-sintered alloys were characterized by scanning electron microscopy (SEM) and also X-Ray diffraction analysis (XRD). Microstructure characterization showed different CaH2 content in the alloy would give different type of pores. There was a tendency of increasing pore size and rough grain along with higher content of CaH2. Further, XRD analysis indicated that s...