67 research outputs found
Cooling rate effects on grain size, eutectic modification and Fe-bearing intermetallic precipitation in hypoeutectic Al-Si alloys
Get PDFAluminum-silicon alloys are the most common aluminum casting alloys produced due to their fluidity characteristic and mechanical and light weight properties. However, there are several issues concerning application of Al-Si hypoeutectic alloys such as strength, which may be improved by refining grain size of the alloy and modifying silicon precipitates. Furthermore, precipitation of Fe-bearing intermetallics such as the so-called beta phase has a detrimental effect on tensile and ductility properties of Al-Si hypoeutectic alloys. Although various methods have been proposed to mitigate the effect of beta phase, the understanding of the mechanism of growth may be useful to reduce its detrimental effects. The objective of this study is to establish the relationship between the cooling rate and morphology features in Al-Si hypoeutectic alloys. In real casting condition, cooling rate is one of the factors that is not easy to predict, because it is related to the geometry of the parts and to the casting process itself. Changes in cooling rate affect the solidification process, and this is made apparent by the changes in the characteristic temperatures of cooling curves recorded in different locations of a part. The relation between these characteristic temperatures and grain size and eutectic silicon modification are presented. Furthermore, the present study also includes the effect of cooling rate on the morphology of beta phase in the case of a ternary Al-Fe-Si alloy. An attempt to characterize the growth of beta phase was performed through post-mortem and in-situ tomography. In addition, some variations from usual solidification features such as script monoclinic phase and rosettes were observed and are discussed
Effect of samarium in corrosion and microstructure of Al-5Zn-0.5Cu as low driving voltage sacrificial anode
No full textEffet de la vitesse de refroidissement sur la taille des grains, la modification eutectique et la précipitation d’intermétalliques riches en fer dans des alliages Al-Si hypoeutectiques
No full textAluminum-silicon alloys are the most common aluminum casting alloys produced due to their fluidity characteristic and mechanical and light weight properties. However, there are several issues concerning application of Al-Si hypoeutectic alloys such as strength, which may be improved by refining grain size of the alloy and modifying silicon precipitates. Furthermore, precipitation of Fe-bearing intermetallics such as the so-called beta phase has a detrimental effect on tensile and ductility properties of Al-Si hypoeutectic alloys. Although various methods have been proposed to mitigate the effect of beta phase, the understanding of the mechanism of growth may be useful to reduce its detrimental effects. The objective of this study is to establish the relationship between the cooling rate and morphology features in Al-Si hypoeutectic alloys. In real casting condition, cooling rate is one of the factors that is not easy to predict, because it is related to the geometry of the parts and to the casting process itself. Changes in cooling rate affect the solidification process, and this is made apparent by the changes in the characteristic temperatures of cooling curves recorded in different locations of a part. The relation between these characteristic temperatures and grain size and eutectic silicon modification are presented. Furthermore, the present study also includes the effect of cooling rate on the morphology of beta phase in the case of a ternary Al-Fe-Si alloy. An attempt to characterize the growth of beta phase was performed through post-mortem and in-situ tomography. In addition, some variations from usual solidification features such as script monoclinic phase and rosettes were observed and are discussed.Les alliages aluminium-silicium sont les alliages d’aluminium de moulage les plus couramment employés en raison de leur faible poids, de leurs caractéristiques mécaniques et de leur fluidité. Leurs propriétés mécaniques, en particulier leur résistance, peuvent être améliorées par l’affinage des grains et la modification des précipités de silicium. Par contre, la précipitation de composés intermétalliques riches en fer, comme la phase dite beta, a un effet néfaste sur la tenue en traction et la ductilité de ces alliages. Bien que diverses méthodes aient été proposées pour atténuer les effets de la phase beta, la compréhension des mécanismes de sa croissance pourrait s’avérer utile pour réduire ses effets néfastes. L’objectif de cette étude est d’établir la relation entre la vitesse de refroidissement et les caractéristiques microstructurales des alliages Al-Si hypoeutectiques. Dans une pièce coulée réelle, la vitesse de refroidissement locale peut grandement changer d’un point à l’autre du fait de la géométrie de la pièce mais aussi du fait des paramètres de coulée. Les variations de vitesse de refroidissement affectent le processus de solidification, et ceci est rendu évident par les changements des températures caractéristiques des courbes de refroidissement enregistrées en différents endroits d’une pièce. Les relations entre ces températures caractéristiques et la taille des grains et la modification du silicium eutectique sont présentées. Cette étude a aussi porté sur l’effet de la vitesse de refroidissement sur la morphologie de la phase beta dans le cas d’un alliage ternaire Al-Fe-Si. La croissance de la phase beta a été caractérisée par tomographie post-mortem et in-situ. Enfin, certains écarts par rapport aux caractéristiques de solidification usuelles, telles que la précipitation en écriture chinoise de la phase beta et la formation de rosettes, ont été observés et sont discutés
PENERAPAN SSAS GUNA MENGATASI PEROMPAKAN DI ATAS KAPAL MV. KT 02
Get PDFFerdian Hernawan, 2018, NIT: 50134873.N, “Application of SSAS to Resolve
Piracy On The Vessel MV. KT 02”, thesis of Nautical Study Program,
Diploma IV Progra, Politeknik Ilmu Pelayaran Semarang, Counselor I:
Capt. I Kadek Laju, SH, MM, M.Mar, Counselor II: R.A.J Susilo Hadi
Wibowo, S.IP, MM.
Piracy becomes one of the causes that the vessel can’t sailing with care and
safely, with thus thing Ship Security Alert System (SSAS) security system
required that was a part of ISPS Code. Because of that SSAS need to be applied
on the vessel to resolve piracy aboard and minimize terrorist act to a minimum.
In this research, learned the factors that was causing lack of understanding
of SSAS aboard and studying the efforts that must be done for solving piracy by
implementing SSAS.
Remembering the importance of SSAS, in this thing author uses qualitative
method with analysis data method is fishbone diagram and fault tree analysis
method. Where is fishbone diagram method use for identifying root of caused that
was happened, while fault tree analysis use for looking efforts that must be done
about problems that was happened.
The results shows the factors that caused SSAS less understood is lack of
socialization, rare drill, drill isn’t appropriate with procedure and lack of
knowledge about SSAS. And result from this research indicate that efforts must
be done is routinely held safety meeting, controlling, routine held drill and also
make a manual book to be learned by all crew.
By implementing these efforts is expected application of SSAS can be move
accordance with the procedure at ISPS Code and security on the vessel can be
more guarded until sailing activities can be moved with smooth and no harm to
peope and company be concerned.
Keywords: application of SSAS, piracy
Austenite to Ferrite Transformation after Hot Deformation of Low Carbon Steel
No full textThe aim of this work is to get the ferrite nucleation criteria from the recrystallized austenite grain after hot deformation in non isothermal condition. A series of rolling experiments have been performed with industrial C-Mn steel in two different temperatures of 1060 and 960 °C with sequence cooling cycle. The microstructure changes that taking place during hot rolling and after cooling has been examined by metallographic evaluation which allows the identification of ferrite transformation after austenite recrystallization. The recrystallization control was carried out using interrupted cooling method to obtain transformation from actual austenite grain. Using an approach of grain boundary interfacial area (Sv) calculation, which attempts to account the number of sites for potential nucleation of ferrite in thermomechanically processed austenite, an essential correlation of the correspond measured grains was developed. The influence of delay interval time after recrystallization to transformation is observed and the implication obtained is discussed. From those results, a hypothetical interaction between parameter and nucleation is described. It is concluded that, strain and holding time has a major role on the recrystallization process of austenite and bring an effect to ferrite grain refinement. The calculated Sv has indicated the potential sites of nucleation that are proliferated with increasing strain.</jats:p
Evaluation of (Al)-Si Eutectic Reference Temperature of A3xx Alloys
Get PDFThe modification level of Al-Si alloys is generally evaluated by the depression of the (Al)-Si eutectic temperature which can be recorded by thermal analysis. However, this method requires a reference temperature which should be the eutectic temperature evaluated on the relevant phase diagram. Various methods proposed to account for the effect of low level alloying elements on this reference temperature are reviewed and emphasis is put on the so-called Mondolfo's equation which is updated. Predictions are compared to experimental information from literature
POLA PEMBINAAN AKHLAK SISWA DI MI AL KHAIRIYAH KUPANG TEBA TELUK BETUNG
Get PDFABSTRAK
POLA PEMINAAN AKHLAK SISWA DI MI AL KHAIRIYAH
KUPANG TEBA TELUK BETUNG
OLEH
DONNY ARYA FERDIAN
Pola pembinaan akhlak siswa adalah usaha yang dilakukan secara
sadar, berencana, dan terarah serta teratur pada suatu pengelolaan,
pembinaan serta mendidik siswa kepada ajaran baik dalam
membentuk sikap, tingkah laku. Tingkah laku merupakan salah satu
karakteristik penting dari manusia sebagai makhluk sosial. Kita sering
kali melakukan penilaian baik dan buruk, dan penilaian tersebut
berpengaruh pada bagaimana kita berperilaku dan memperlakukan
orang lain.
Penelitian ini bertujuan untuk mengetahui Mengetahui Pola
pembinaan Akhlak Siswa Di Mi Al Khairiyah Kupang Teba Teluk
Betung.
Penelitian ini menggunakan metode deskripstif kualitatif , dalam
pengumpulan data penulis menggunakan metode wawancara,
observasi dan dokumentasi. Adapun dataprimer yang digunakan yaitu
wawancara yag dilakukan dengan kepala sekolah, guru PAI dan siswa
kelas IV MI al Khairiyah kupang teluk betung. Data sekunder yang
peneliti gunakan yaitu buku-buku yang berkaitan dengan pembinaan
akhlak. HasilPeneliian menunjukkan bahwa pola pembinaan akhlak
yang digunakan di MI Al Khairiyah Kupang Teba Teluk Betung
adalah menggunakan pola pembinaan melalui pembiasaan dan pola
pembinaan melalui modelling. Pola pembiasan ini diantaranya adalah
dengan membiasakan hal-hal kecil seperti senyum, sapa, salam,
kepada seluruh warga Masyarakat khususnya yang ada didalam kelas.
Untuk pola Modelling guru melakukan usahanya dengan menjadikan
dirinya sebgai role model dengan selalu membiasakan sholat
berjamaah. Selain melalui pola pembiasaan dan modelling, guru
Aqidah Akhlak melakukan pola pembinaan pada siswa dengan
menggunakan metode pembinaan demokrasi.
Kata Kunci : Pola, Pembinaan, Akhlak
iv
ABSTRACT
PATTERNS OF IMPROVING STUDENTS' MALACTS AT MI AL
KHAIRIYAH KUPANG TEBA TELUK BETUNG
BY
DONNY ARYA FERDIAN
The pattern of developing student morals is an effort carried
out consciously, planned, and directed and regularly in managing,
coaching and educating students to good teachings in forming
attitudes and behavior. Behavior is one of the important
characteristics of humans as social creatures. We often make
judgments about good and bad, and these judgments influence how we
behave and treat other people.
This research aims to determine the knowledge of students'
moral training patterns at Mi Al Khairiyah Kupang Teba Teluk
Betung.
This research uses a qualitative descriptive method, in
collecting data the author uses interview, observation and
documentation methods. The primary data used were interviews
conducted with the principal, PAI teacher and class IV students at MI
Al Khairiyah Kupang Teluk Betung. The secondary data that
researchers use are books related to moral training. Results
Research shows that the moral coaching pattern used at MI Al
Khairiyah Kupang Teba Teluk Betung is to use a coaching pattern
through habituation and a coaching pattern through modeling. This
pattern of refraction includes getting used to small things such as
smiling, saying hello, greetings to all members of the community,
especially those in the classroom. For the modeling pattern, the
teacher makes his efforts by making himself a role model by always
getting into the habit of praying in congregation. Apart from using
habituation and modeling patterns, the Aqidah Akhlak teacher carries
out coaching patterns for students using democratic coaching
methods.
Keywords: Patterns, Development, Moral
Surface quality and microstructure of low-vacuum sintered orthodontic bracket 17-4 PH stainless steel fabricated by MIM process
No full textAnalysis of external corrosion protection performance on buried gas pipeline using CIPS and DCVG methods
No full textThe present work investigates the effectiveness of external corrosion protection using Close Interval Potential Survey (CIPS) and Direct Current Voltage Gradient (DCVG) on a buried gas pipeline. These surveys were performed on 12” gas pipeline in East Kalimantan. Coating and cathodic protection were the primary corrosion protection on these pipelines. Soil resistivity measurement was conducted every km along the pipeline to obtain the resistivity profile combined with the pH profile. CIPS showed that the Cathodic Protection system protects 79.21 % of the pipeline area. There is no sign of telluric or stray current effect from the result of CIPS. DCVG showed 159 defects that can be divided into three different clusters. There is 6-point coating defects that should be repaired immediately due to the characteristics and category of the defect. The integrated data analysis of CIPS and DCVG showed a correlation which dips pattern on CIPS graph indicating coating defect on DCVG surveyed. Soil resistivity measurement showed that the soil resistivity profile is negligible from KP 0 – 5, while KP 5 – 14 is mildly corrosive. pH measurement showed the acidity level or the soil along the pipeline were neutral. Cathodic protection level could be improved with the increase of cathodic protection current and coating repair along the area with low-level protection
Synthesis of TiO2 Nanotube in TI-10Ta-10Nb Thin Film by Anodization
Get PDFThe purpose of this research was to study the synthesis of TiO2
nanotubes on Ti-10Ta-10Nb thin film and the effect of applied potential
on the tube size, length and morphology. The Ti-10Ta-10Nb thin film was
deposited by dc magnetron sputtering on the CP Ti substrate. The
anodization of this Ti-10Ta-10Nb thin film was performed in the solution
containing 1M H3PO4 + 1.5wt.% HF at the potential readings of 4, 6, 8
and 10 V for 10 minutes. The results showed that there was a slight
increase in the tube diameter from approximately 25 nm at 4 V to 50 nm
at 8 V. The length of nanotube varied from 700-900 nm. Interestingly, at
the potential of 10 V, the nanotube diameters were damaged with slight
decreases in nanotube lengths (500 nm)
- …
