Pub Date : 2021-04-29DOI: 10.14203/METALURGI.V36I1.577
R. M. Ulum
The utilization of slag as a secondary resource is usually processed by a reduction process with coal reducing agents or by leaching process. However, this study will use palm kernel shell as an alternative reducing agent to substitute coal. Palm kernel shell was chosen as an alternative reducing agent because of their availability in Indonesia. The purpose of this study is to determine the effect of palm kernel shell as reducing agent and its concentration (wt.%) to the ferronickel slag reduction process. The initial sample is ferronickel slag which had been proceed by alkali fusion by adding 20 wt.% sodium carbonate (Na 2 CO 3 ) as an additive and then roasted. The roasted product is then mixed with palm kernel shell reductant by ratio (sample : reductant), which are 15:85, 20:80, and 25:75 in weight percent. Samples that have been mixed are then compacted using compacting machine. Then the reduction process is carried out using a tube furnace at a temperature of 1100°C for 60 minutes with a heating rate of 10°C/minute. The palm kernel shells were analyzed using ultimate and proximate analysis, while the reduced product is then characterized by SEM-EDS and XRD for further analysis. Based on the results of the characterization, in this study it was found that the reduction process using palm kernel shell produces products in the form of iron metal, magnetite, hematite, and sodium silicate. The optimum reducing agent concentration in this study is by adding 15 wt.% reductant.
{"title":"THE PRODUCT CHARACTERISTICS OF TREATED-FERRONICKEL SLAG PRODUCED BY ALKALI FUSION AND CARBOTHERMIC PROCESS","authors":"R. M. Ulum","doi":"10.14203/METALURGI.V36I1.577","DOIUrl":"https://doi.org/10.14203/METALURGI.V36I1.577","url":null,"abstract":"The utilization of slag as a secondary resource is usually processed by a reduction process with coal reducing agents or by leaching process. However, this study will use palm kernel shell as an alternative reducing agent to substitute coal. Palm kernel shell was chosen as an alternative reducing agent because of their availability in Indonesia. The purpose of this study is to determine the effect of palm kernel shell as reducing agent and its concentration (wt.%) to the ferronickel slag reduction process. The initial sample is ferronickel slag which had been proceed by alkali fusion by adding 20 wt.% sodium carbonate (Na 2 CO 3 ) as an additive and then roasted. The roasted product is then mixed with palm kernel shell reductant by ratio (sample : reductant), which are 15:85, 20:80, and 25:75 in weight percent. Samples that have been mixed are then compacted using compacting machine. Then the reduction process is carried out using a tube furnace at a temperature of 1100°C for 60 minutes with a heating rate of 10°C/minute. The palm kernel shells were analyzed using ultimate and proximate analysis, while the reduced product is then characterized by SEM-EDS and XRD for further analysis. Based on the results of the characterization, in this study it was found that the reduction process using palm kernel shell produces products in the form of iron metal, magnetite, hematite, and sodium silicate. The optimum reducing agent concentration in this study is by adding 15 wt.% reductant.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"36 1","pages":"1-6"},"PeriodicalIF":0.6,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47101535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-29DOI: 10.14203/METALURGI.V36I1.574
D. N. Adnyana
This study was carried out on a compressor heat exchanger (after-cooler) which had a leak in the welded joint of its components made of non-heat treatable aluminum alloys. The purpose of this study is to determine the type and cause, and mechanisms of failure associated with the metallurgical structure that occurs. In this study a number of tests have been carried out including visual and macroscopic examinations, metallographic and hardness testing, and SEM (scanning electron microscopy) analysis equipped with EDS (energy dispersive spectroscopy). The results of the study obtained indicate that the failure mechanism that causes leakage in the aluminum alloy welding joints of the compressor heat exchanger component is intergranular corrosion due to sensitization and the related effect of environmental factors that occur. In addition, the failure may also be affected by welding defect in the form of pinholes.
{"title":"STUDY OF INTERGRANULAR CORROSION ON NON-HEAT TREATABLE ALUMINUM ALLOYS IN A COMPRESSOR AFTER-COOLER","authors":"D. N. Adnyana","doi":"10.14203/METALURGI.V36I1.574","DOIUrl":"https://doi.org/10.14203/METALURGI.V36I1.574","url":null,"abstract":"This study was carried out on a compressor heat exchanger (after-cooler) which had a leak in the welded joint of its components made of non-heat treatable aluminum alloys. The purpose of this study is to determine the type and cause, and mechanisms of failure associated with the metallurgical structure that occurs. In this study a number of tests have been carried out including visual and macroscopic examinations, metallographic and hardness testing, and SEM (scanning electron microscopy) analysis equipped with EDS (energy dispersive spectroscopy). The results of the study obtained indicate that the failure mechanism that causes leakage in the aluminum alloy welding joints of the compressor heat exchanger component is intergranular corrosion due to sensitization and the related effect of environmental factors that occur. In addition, the failure may also be affected by welding defect in the form of pinholes.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"36 1","pages":"7"},"PeriodicalIF":0.6,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66753700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-29DOI: 10.14203/METALURGI.V36I1.579
Miftakhur Rohmah
High strength low alloy (HSLA) yang diaplikasikan menjadi baja tahan cuaca merupakan terobosan terbaru untuk menghasilkan sifat mekanik dan ketahanan korosi yang tinggi. Modifikasi Baja Laterit dengan penambahan kadar nikel yang diterapkan proses termomekanikal (TMCP) berupa kombinasi proses penempaan panas dan perlakuan panas menjadi fokusan penelitian ini. Sampel yang digunakan merupakan Baja Laterit A-588 hasil investment casting yang telah ditambahkan kadar nikel sebesar 1, 2, dan 3% kemudian diproses penempaan panas dengan pembebanan 100 ton pada temperatur 1050 ℃. Nikel berfungsi sebagai penstabil austenit. Variabel perlakuan panas yang digunakan yakni (1) langsung pendinginan udara, (2) dilanjutkan proses pemanasan pada temperatur 750 ℃ yang diikuti pendinginan cepat. Karakterisasi material menggunakan uji metalografi, uji keras, uji tarik, dan uji polarisasi. Pada sampel tempa panas+pendinginan udara, pertambahan kadar nikel hingga 3% mempengaruhi nilai fraksi fasa ferrit-perlit yang terbentuk, pertambahan ukuran butir hingga ±0,1 mm, penurunan kekerasan hingga 185,22 BHN, penurunan kekuatan hingga 554 MPa, dan pertambahkan elongasi sebesar 29.1%. Sedangkan pada sampel tempa panas+perlakuan panas dengan pendinginan air, pertambahan nikel hingga 3% menyebabkan terbentuknya fasa dislokasi lath martensit+ferrit+retained austenite, penurunan kekerasan hingga 236,18 BHN, penurunan kekuatan hingga 852 MPa, penurunan elongasi hingga 24,7%. Fasa retained austenite memiliki efek merusak pada sifat mekanis.
{"title":"PENGARUH PENEMPAAN DAN PERLAKUAN PANAS TERHADAP SIFAT MEKANIK DAN KETAHANAN KOROSI PADA MODIFIKASI BAJA LATERIT A-588","authors":"Miftakhur Rohmah","doi":"10.14203/METALURGI.V36I1.579","DOIUrl":"https://doi.org/10.14203/METALURGI.V36I1.579","url":null,"abstract":"High strength low alloy (HSLA) yang diaplikasikan menjadi baja tahan cuaca merupakan terobosan terbaru untuk menghasilkan sifat mekanik dan ketahanan korosi yang tinggi. Modifikasi Baja Laterit dengan penambahan kadar nikel yang diterapkan proses termomekanikal (TMCP) berupa kombinasi proses penempaan panas dan perlakuan panas menjadi fokusan penelitian ini. Sampel yang digunakan merupakan Baja Laterit A-588 hasil investment casting yang telah ditambahkan kadar nikel sebesar 1, 2, dan 3% kemudian diproses penempaan panas dengan pembebanan 100 ton pada temperatur 1050 ℃. Nikel berfungsi sebagai penstabil austenit. Variabel perlakuan panas yang digunakan yakni (1) langsung pendinginan udara, (2) dilanjutkan proses pemanasan pada temperatur 750 ℃ yang diikuti pendinginan cepat. Karakterisasi material menggunakan uji metalografi, uji keras, uji tarik, dan uji polarisasi. Pada sampel tempa panas+pendinginan udara, pertambahan kadar nikel hingga 3% mempengaruhi nilai fraksi fasa ferrit-perlit yang terbentuk, pertambahan ukuran butir hingga ±0,1 mm, penurunan kekerasan hingga 185,22 BHN, penurunan kekuatan hingga 554 MPa, dan pertambahkan elongasi sebesar 29.1%. Sedangkan pada sampel tempa panas+perlakuan panas dengan pendinginan air, pertambahan nikel hingga 3% menyebabkan terbentuknya fasa dislokasi lath martensit+ferrit+retained austenite, penurunan kekerasan hingga 236,18 BHN, penurunan kekuatan hingga 852 MPa, penurunan elongasi hingga 24,7%. Fasa retained austenite memiliki efek merusak pada sifat mekanis.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"36 1","pages":"33"},"PeriodicalIF":0.6,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48579614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-29DOI: 10.14203/METALURGI.V36I1.583
Made Subekti Dwijaya, Muhammad Satrio Utomo, Syafira Nur Ajeng Ramadhanti, Fendy Rokhmanto, Ibrahim Purawiardi, Galih Senopati, Aprilia Erryani, Inti Mulyati
Osseointegration is one of important property in development of implant materials for orthopedic applications. While biocompatible metallic materials such as titanium alloys should already have adequate biocompatibility properties as implant materials, their osseointegration property could be further improved by bioceramic coating. Calcium carbonate (CaCO3) and hydroxyapatite are two major bioceramics in bones that can be utilized to improve the osseointegration property of metallic implant materials. Current challenge on bioceramic coating of metallic implant materials is to obtain coating method that is facile and economically feasible for implementation in the industry. Here we propose a simple and straightforward method to deposit calcium carbonate on Ti-6Al-6Mo. We utilize two common biomimetic solutions, the phosphate buffer saline (Dulbecco’s PBS) and supersaturated calcification solution (SCS) to induce the calcium carbonate formation on the Ti-6Al-6Mo surface. Microstructural and elemental observations by scanning electron microscope (SEM) – energy dispersive x-ray (EDX) has shown the presence of calcium carbonate on the surface of the Ti-6Al-6Mo immersed in SCS. Moreover, the crystallography analysis by x-ray diffraction (XRD) also confirmed the formation of calcium carbonate on the surface of Ti-6Al-6Mo. We also studied the proposed method on pure Ti (>95%) as comparison and similar outcomes were also observed. The effect on duration of immersion was also accounted in current setting. The outcomes of immersion duration for 7 and 10 days were not significantly different. ABSTRAKOsseointegrasi adalah salah satu properti penting dalam pengembangan material untuk aplikasi implan tulang. Meskipun material logam biokompatibel seperti paduan titanium sudah memiliki properti biokompatibel bawaan yang sudah mencukupi sebagai material implan tulang, sifat osseointegrasi -nya masih dapat ditingkatkan dengan pelapisan biokeramik. Kalsium karbonat (CaCO3) dan hidroksiapatit adalah dua biokeramik utama pada tulang yang dapat dimanfaatkan untuk meningkatkan sifat osseointegrasi pada material implan. Tantangan saat ini pada pelapisan biokeramik pada material implant adalah memperoleh metode pelapisan yang mudah diterapkan dan ekonomis untuk selanjutnya diterapkan di industri. Pada penelitian ini dilakukan sebuah metode yang sederhana untuk mendeposisi kalsium karbonat pada permukaan Ti-6Al-6Mo. Kami menggunakan dua larutan biomimetik yang sudah secara luas digunakan, yaitu Dulbecco’s PBS (phosphate buffer saline) dan SCS (supersaturated calcification solution) untuk membuat pembentukan kalsium karbonat pada permukaan Ti-6Al-6Mo. Pengamatan struktur mikro dan elemental dengan scanning electron microscope (SEM) - energy dispersive x-ray (EDX) menunjukkan keberadaan deposit kalsium karbonat pada permukaan Ti-6Al-6Mo. Lebih lanjut, analisa kristalografi dengan difraksi x-ray (XRD) juga menguatkan keberadaan deposit kalsium karbonat pada permukaan Ti-6Al-
{"title":"Deposisi Kalsium Karbonat pada Ti-6Al-6Mo[CALCIUM CARBONATE DEPOSITION ON TI-6AL-6MO]","authors":"Made Subekti Dwijaya, Muhammad Satrio Utomo, Syafira Nur Ajeng Ramadhanti, Fendy Rokhmanto, Ibrahim Purawiardi, Galih Senopati, Aprilia Erryani, Inti Mulyati","doi":"10.14203/METALURGI.V36I1.583","DOIUrl":"https://doi.org/10.14203/METALURGI.V36I1.583","url":null,"abstract":"Osseointegration is one of important property in development of implant materials for orthopedic applications. While biocompatible metallic materials such as titanium alloys should already have adequate biocompatibility properties as implant materials, their osseointegration property could be further improved by bioceramic coating. Calcium carbonate (CaCO3) and hydroxyapatite are two major bioceramics in bones that can be utilized to improve the osseointegration property of metallic implant materials. Current challenge on bioceramic coating of metallic implant materials is to obtain coating method that is facile and economically feasible for implementation in the industry. Here we propose a simple and straightforward method to deposit calcium carbonate on Ti-6Al-6Mo. We utilize two common biomimetic solutions, the phosphate buffer saline (Dulbecco’s PBS) and supersaturated calcification solution (SCS) to induce the calcium carbonate formation on the Ti-6Al-6Mo surface. Microstructural and elemental observations by scanning electron microscope (SEM) – energy dispersive x-ray (EDX) has shown the presence of calcium carbonate on the surface of the Ti-6Al-6Mo immersed in SCS. Moreover, the crystallography analysis by x-ray diffraction (XRD) also confirmed the formation of calcium carbonate on the surface of Ti-6Al-6Mo. We also studied the proposed method on pure Ti (>95%) as comparison and similar outcomes were also observed. The effect on duration of immersion was also accounted in current setting. The outcomes of immersion duration for 7 and 10 days were not significantly different. ABSTRAKOsseointegrasi adalah salah satu properti penting dalam pengembangan material untuk aplikasi implan tulang. Meskipun material logam biokompatibel seperti paduan titanium sudah memiliki properti biokompatibel bawaan yang sudah mencukupi sebagai material implan tulang, sifat osseointegrasi -nya masih dapat ditingkatkan dengan pelapisan biokeramik. Kalsium karbonat (CaCO3) dan hidroksiapatit adalah dua biokeramik utama pada tulang yang dapat dimanfaatkan untuk meningkatkan sifat osseointegrasi pada material implan. Tantangan saat ini pada pelapisan biokeramik pada material implant adalah memperoleh metode pelapisan yang mudah diterapkan dan ekonomis untuk selanjutnya diterapkan di industri. Pada penelitian ini dilakukan sebuah metode yang sederhana untuk mendeposisi kalsium karbonat pada permukaan Ti-6Al-6Mo. Kami menggunakan dua larutan biomimetik yang sudah secara luas digunakan, yaitu Dulbecco’s PBS (phosphate buffer saline) dan SCS (supersaturated calcification solution) untuk membuat pembentukan kalsium karbonat pada permukaan Ti-6Al-6Mo. Pengamatan struktur mikro dan elemental dengan scanning electron microscope (SEM) - energy dispersive x-ray (EDX) menunjukkan keberadaan deposit kalsium karbonat pada permukaan Ti-6Al-6Mo. Lebih lanjut, analisa kristalografi dengan difraksi x-ray (XRD) juga menguatkan keberadaan deposit kalsium karbonat pada permukaan Ti-6Al-","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"36 1","pages":"17"},"PeriodicalIF":0.6,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46574733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-29DOI: 10.14203/METALURGI.V36I1.584
Andi Mulya Ashari
Magnesium and its alloys are promising candidates for degradable materials with good biocompatibility. Alloys based on Mg-Zn-Fe-Cu-Co compositions were designed using the equiatomic method of high entropy alloy. This paper discusses the microstructure and mechanical properties of these new high entropy alloys. Pure Magnesium (60 µm), Zinc (45 µm), Fe (10 µm), Cu (63 µm), and Co (1 µm) powder were mixed and milled using a shaker mill at 700 rpm for the 1800s. The resulting milled powders were compacted and sintered at 300 MPa for 180s and 600 MPa for 120s. Sintering was performed at 700 o C for 2 hours in a tube vacuum furnace at a 5 °C/min heating rate under a high purity argon atmosphere. Microstructural analyses and mechanical tests were performed based on the American standard of testing and measurement. The a lloys were basically multiphase and crystalline. The 20Mg-20Zn-20Fe-20Cu-20Co alloy consisted of the HCP phase and cubic phase. The physical and mechanical properties of Mg-Zn-Fe-Cu-Co were affected by the magnesium content in the matrix alloys. The presence of pores indicated uncomplete compaction and sintering process. The alloys have a medium hardness of between 286.06 HV - 80.98 HV, while the densities of the alloys were relatively moderate in the range of 3.057 g.cm -3 to 1.71 g.cm -3 . Solid solution and intermetallic precipitation strengthening were believed the primary strengthening mechanics of the alloys. It is concluded that high entropy is a promising method for the processing of Mg alloys. Alloy with a chemical composition of 20Mg-20Zn-20Fe-20Cu-20Co had optimal mechanical properties that meet the minimum requirements of high entropy alloys as candidates for ureteral implant applications.
{"title":"STUDY TO MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Mg-Zn-Fe-Cu-Co AS HIGH ENTROPY ALLOYS FOR URETERAL IMPLANT APPLICATION","authors":"Andi Mulya Ashari","doi":"10.14203/METALURGI.V36I1.584","DOIUrl":"https://doi.org/10.14203/METALURGI.V36I1.584","url":null,"abstract":"Magnesium and its alloys are promising candidates for degradable materials with good biocompatibility. Alloys based on Mg-Zn-Fe-Cu-Co compositions were designed using the equiatomic method of high entropy alloy. This paper discusses the microstructure and mechanical properties of these new high entropy alloys. Pure Magnesium (60 µm), Zinc (45 µm), Fe (10 µm), Cu (63 µm), and Co (1 µm) powder were mixed and milled using a shaker mill at 700 rpm for the 1800s. The resulting milled powders were compacted and sintered at 300 MPa for 180s and 600 MPa for 120s. Sintering was performed at 700 o C for 2 hours in a tube vacuum furnace at a 5 °C/min heating rate under a high purity argon atmosphere. Microstructural analyses and mechanical tests were performed based on the American standard of testing and measurement. The a lloys were basically multiphase and crystalline. The 20Mg-20Zn-20Fe-20Cu-20Co alloy consisted of the HCP phase and cubic phase. The physical and mechanical properties of Mg-Zn-Fe-Cu-Co were affected by the magnesium content in the matrix alloys. The presence of pores indicated uncomplete compaction and sintering process. The alloys have a medium hardness of between 286.06 HV - 80.98 HV, while the densities of the alloys were relatively moderate in the range of 3.057 g.cm -3 to 1.71 g.cm -3 . Solid solution and intermetallic precipitation strengthening were believed the primary strengthening mechanics of the alloys. It is concluded that high entropy is a promising method for the processing of Mg alloys. Alloy with a chemical composition of 20Mg-20Zn-20Fe-20Cu-20Co had optimal mechanical properties that meet the minimum requirements of high entropy alloys as candidates for ureteral implant applications.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"36 1","pages":"25-32"},"PeriodicalIF":0.6,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45044835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-04DOI: 10.31044/0543-5846-2021-60-55-58
Yulia Li, S. Barannikova
S. Barannikova, Yu. Li (e-mail: jul2207@mail.ru), Institute of Strength Physics and Materials Science of Siberian Branch Russian Academy of Sciences (ISPMS SB RAS), Tomsk, Russia; National Research Tomsk State University, Tomsk, Russia; Tomsk State Architecture and Building University, Tomsk, Russia The present work is aimed at studying the macroscopic localization of plastic strain in low-carbon steel AISI A283 Grade C. The evolution of macroscopically localized plastic strain at various stages of strain hardening is visualized via a Digital image speckle correlation (DISC) method. The processing of stress-strain curves of the steel samples enabled one to distinguish the following stages of strain hardening: the yield point, the parabolic hardening, and the pre-failure. The inspection of local strain distributions reveals that the parabolic work hardening is presented by a system of stationary plastic strain centers placed at equal distances. To perform a comprehensive analysis of local elongations from the parabolic work hardening toward the pre-failure stage, the total elongation components were measured at the strain centers. The average total elongation is found to be almost constant at the parabolic work hardening, but abruptly increases when approaching the pre-failure stage. The plastic strain instability is highlighted, as well, by the rising total elongation (amplitude) at the strain sites.
{"title":"In situ digital image speckle correlation (DISC) observation of plastic strain increment in low-carbon steel","authors":"Yulia Li, S. Barannikova","doi":"10.31044/0543-5846-2021-60-55-58","DOIUrl":"https://doi.org/10.31044/0543-5846-2021-60-55-58","url":null,"abstract":"S. Barannikova, Yu. Li (e-mail: jul2207@mail.ru), Institute of Strength Physics and Materials Science of Siberian Branch Russian Academy of Sciences (ISPMS SB RAS), Tomsk, Russia; National Research Tomsk State University, Tomsk, Russia; Tomsk State Architecture and Building University, Tomsk, Russia The present work is aimed at studying the macroscopic localization of plastic strain in low-carbon steel AISI A283 Grade C. The evolution of macroscopically localized plastic strain at various stages of strain hardening is visualized via a Digital image speckle correlation (DISC) method. The processing of stress-strain curves of the steel samples enabled one to distinguish the following stages of strain hardening: the yield point, the parabolic hardening, and the pre-failure. The inspection of local strain distributions reveals that the parabolic work hardening is presented by a system of stationary plastic strain centers placed at equal distances. To perform a comprehensive analysis of local elongations from the parabolic work hardening toward the pre-failure stage, the total elongation components were measured at the strain centers. The average total elongation is found to be almost constant at the parabolic work hardening, but abruptly increases when approaching the pre-failure stage. The plastic strain instability is highlighted, as well, by the rising total elongation (amplitude) at the strain sites.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"60 1","pages":"55-58"},"PeriodicalIF":0.6,"publicationDate":"2021-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42942621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.14203/metalurgi.v35i3.572
K. C. Wanta, Felisha Hapsari Tanujaya, Federick Dwi Putra, R. F. Susanti, G. P. Gemilar, W. Astuti, H. T. Petrus
Nickel is an essential metal element and is applied in various sectors. One of the useful nickel–based derivatives products is nickel hydroxide [Ni(OH) 2 ]. This compound is widely applied as raw material for electrodes of rechargeable batteries, capacitors, electrolyzers, and catalysts. This study focuses on the synthesis of Ni(OH) 2 using the hydroxide precipitation method. A solution from the extraction process of spent catalysts was used as a precursor solution. After the precursor solution was obtained, the precipitation process was carried out at pH 10, where the operating temperature was varied at 30–60 o C. NaOH, KOH, and MgO solutions were used as precipitating agents. The experimental results show that the Ni(OH) 2 compounds were produced optimally at low temperatures, 30 o C. It could be indicated from the lowest concentration of Ni 2+ ions in the liquid phase that reached that temperature. The three precipitation agents also gave good results in the precipitation of Ni 2+ ions, where almost all of the Ni 2+ ions were precipitated from the liquid phase. The precipitated products were characterized using SEM, XRD, and XRF. The analysis results showed that the product was agglomerated and formless. The purity of the precipitates formed were 24.1 and 29% for the precipitating agents MgO and NaOH, respectively.
{"title":"SYNTHESIS AND CHARACTERIZATION OF NICKEL HYDROXIDE FROM EXTRACTION SOLUTION OF SPENT CATALYST","authors":"K. C. Wanta, Felisha Hapsari Tanujaya, Federick Dwi Putra, R. F. Susanti, G. P. Gemilar, W. Astuti, H. T. Petrus","doi":"10.14203/metalurgi.v35i3.572","DOIUrl":"https://doi.org/10.14203/metalurgi.v35i3.572","url":null,"abstract":"Nickel is an essential metal element and is applied in various sectors. One of the useful nickel–based derivatives products is nickel hydroxide [Ni(OH) 2 ]. This compound is widely applied as raw material for electrodes of rechargeable batteries, capacitors, electrolyzers, and catalysts. This study focuses on the synthesis of Ni(OH) 2 using the hydroxide precipitation method. A solution from the extraction process of spent catalysts was used as a precursor solution. After the precursor solution was obtained, the precipitation process was carried out at pH 10, where the operating temperature was varied at 30–60 o C. NaOH, KOH, and MgO solutions were used as precipitating agents. The experimental results show that the Ni(OH) 2 compounds were produced optimally at low temperatures, 30 o C. It could be indicated from the lowest concentration of Ni 2+ ions in the liquid phase that reached that temperature. The three precipitation agents also gave good results in the precipitation of Ni 2+ ions, where almost all of the Ni 2+ ions were precipitated from the liquid phase. The precipitated products were characterized using SEM, XRD, and XRF. The analysis results showed that the product was agglomerated and formless. The purity of the precipitates formed were 24.1 and 29% for the precipitating agents MgO and NaOH, respectively.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"35 1","pages":"111-118"},"PeriodicalIF":0.6,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49205265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.14203/metalurgi.v35i3.567
Aprilia Erryani
Pada penelitian ini telah dilakukan pembuatan implan bioabsorbable dengan bahan polimer logam komposit (PLA/ABS/Mg) dengan menggunakan metode solvent casting dengan tiga komposisi yakni PLA:ABS 70:30, 60:40, 80:20 dengan komposisi Mg masing-masing 5%, 10% dan 15% kemudian dilarutkan dengan clorofoam sebanyak 17 mL sehingga mendapatkan sampel berbentuk film. Penelitian ini bertujuan untuk mengetahui variasi optimal PLA/ABS terhadapat karakterisitik sifat mekanik, morfologi, impedansi dengan adanya penambahan Mg. Hasil karakterisasi sifat mekanik menggunakan uji tarik dengan komposisi PLA:ABS 80:20 pada variasi Mg 10% dan 15% menunjukkan hasil yang optimal, sehingga Mg terbukti meningkatkan sifat mekanik dari PLA. Semakin banyak penambahan variasi Mg menunjukkan peningkatan nilai kekerasan vikers dan impedansi pada polimer logam komposit. Hasil pengamatan dengan menggunakan SEM pada kompoisi PLA:ABS 70:30 menunjukan bahwa homogenitas Mg didalam polimer telah tercapai dengan baik.
{"title":"PENGARUH PENAMBAHAN MAGNESIUM TERHADAP SIFAT MEKANIK, MIKROSTRUKTUR DAN ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY POLIMER PLA/ABS UNTUK MATERIAL IMPLAN BIOABSORBABEL","authors":"Aprilia Erryani","doi":"10.14203/metalurgi.v35i3.567","DOIUrl":"https://doi.org/10.14203/metalurgi.v35i3.567","url":null,"abstract":"Pada penelitian ini telah dilakukan pembuatan implan bioabsorbable dengan bahan polimer logam komposit (PLA/ABS/Mg) dengan menggunakan metode solvent casting dengan tiga komposisi yakni PLA:ABS 70:30, 60:40, 80:20 dengan komposisi Mg masing-masing 5%, 10% dan 15% kemudian dilarutkan dengan clorofoam sebanyak 17 mL sehingga mendapatkan sampel berbentuk film. Penelitian ini bertujuan untuk mengetahui variasi optimal PLA/ABS terhadapat karakterisitik sifat mekanik, morfologi, impedansi dengan adanya penambahan Mg. Hasil karakterisasi sifat mekanik menggunakan uji tarik dengan komposisi PLA:ABS 80:20 pada variasi Mg 10% dan 15% menunjukkan hasil yang optimal, sehingga Mg terbukti meningkatkan sifat mekanik dari PLA. Semakin banyak penambahan variasi Mg menunjukkan peningkatan nilai kekerasan vikers dan impedansi pada polimer logam komposit. Hasil pengamatan dengan menggunakan SEM pada kompoisi PLA:ABS 70:30 menunjukan bahwa homogenitas Mg didalam polimer telah tercapai dengan baik.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"35 1","pages":"89-98"},"PeriodicalIF":0.6,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43759073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-25DOI: 10.14203/metalurgi.v35i2.490
R. Mayasari
Sintesis nano-perovskite neodymium iron oxide (NdFeO 3 ) telah berhasil dilakukan dengan metode presipitasi menggunakan surfaktan ethylene glycol (EG) sebagai coating material . Senyawa NdFeO 3 dikarakterisasi analisis gugus fungsi kimia dengan Fourier transform infrared spectroscopy (FTIR), analisis morfologi dengan scanning electron microscopy (SEM), analisis kristalinitas dan ukuran partikel dengan X-ray diffraction (XRD) dan transmission electron microscopy (TEM). Pengamatan SEM dan TEM menunjukkan bahwa hasil sintesis membentuk nanostruktur berbentuk bulat dengan ukuran diameter pada rentang 15 sampai 20 nm. Spektra XRD mengonfirmasi bahwa fasa NdFeO 3 membentuk struktur orthorombik dan perovskite.
{"title":"Sintesis dan Karakterisasi Material Nano-Perovskite Neodymium Iron Oxide (NdFeO3)","authors":"R. Mayasari","doi":"10.14203/metalurgi.v35i2.490","DOIUrl":"https://doi.org/10.14203/metalurgi.v35i2.490","url":null,"abstract":"Sintesis nano-perovskite neodymium iron oxide (NdFeO 3 ) telah berhasil dilakukan dengan metode presipitasi menggunakan surfaktan ethylene glycol (EG) sebagai coating material . Senyawa NdFeO 3 dikarakterisasi analisis gugus fungsi kimia dengan Fourier transform infrared spectroscopy (FTIR), analisis morfologi dengan scanning electron microscopy (SEM), analisis kristalinitas dan ukuran partikel dengan X-ray diffraction (XRD) dan transmission electron microscopy (TEM). Pengamatan SEM dan TEM menunjukkan bahwa hasil sintesis membentuk nanostruktur berbentuk bulat dengan ukuran diameter pada rentang 15 sampai 20 nm. Spektra XRD mengonfirmasi bahwa fasa NdFeO 3 membentuk struktur orthorombik dan perovskite.","PeriodicalId":18462,"journal":{"name":"Metalurgija","volume":"35 1","pages":"53-56"},"PeriodicalIF":0.6,"publicationDate":"2020-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47978686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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