Performance of Al-6063 Primary and Secondary Billets Used in Hot Aluminum Extrusion

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
S. S. Akhtar ◽  
A. F. M. Arif ◽  
B. S. Yilbas
Keyword(s):  
Service Life ◽  
High Hardness ◽  
Xrd Analysis ◽  
Extrusion Process ◽  
Die Design ◽  
Grain Structure ◽  
Secondary Phases ◽  
Microstructural Investigation ◽  
Extrusion Press ◽  
Die Service Life

The service life of tooling plays an important part in the economics of the extrusion process. A number of causes are considered responsible for initiating damage to the dies before its designated life is reached. Apart from other factors such as die design and manufacturing, heat treatment, working conditions, etc, the performance of the die can directly be related to the billet quality used in the extrusion press. The purpose of this paper is to investigate the effect of Al-6063 billet source (primary or secondary) on extrusion die failure, based on microstructural investigation. A secondary (remelt) billet cast in-house at a local extrusion plant is compared with a primary (smelter) billet by applying different material characterization techniques, including optical microscopy, Vickers microhardness measurement, X-ray diffraction (XRD) analysis, and energy dispersive spectroscopy (EDS). It is observed that a secondary billet has a comparatively coarse grain structure, nonhomogeneous distribution of secondary phases, inclusions, and high hardness that can be associated with poor casting and homogenization practice. In view of present results, some suggestions during in-house billet preparation of secondary billets have been formulated for improved die service life.

Influence of Billet Quality on Hot Extrusion Die Life and its Relationship with Process Parameters

2009 ◽  
Vol 83-86 ◽  
pp. 866-873 ◽  
Author(s):  
S.S. Akhtar ◽  
Abul Fazal M. Arif ◽  
A.K. Sheikh
Keyword(s):  
Process Parameters ◽  
Hot Extrusion ◽  
Die Design ◽  
Grain Structure ◽  
Homogeneous Distribution ◽  
Microstructural Investigation ◽  
Billet Quality ◽  
Extrusion Die ◽  
Die Life ◽  
Die Service Life

Apart from other factors such as die design and manufacturing, heat treatment, working conditions etc, performance of hot extrusion die can directly be related to the billet quality used in the extrusion press. The purpose of this paper is to investigate the effect of Al-6063 billet source (primary or secondary) on extrusion die life based on microstructural and statistical analyses. In microstructural investigation, secondary (remelt) billet cast in-house at local extrusion plant is compared with primary (smelter) billet by applying different material characterization techniques including optical microscopy, hardness measurement, X-ray diffraction (XRD) analysis, and energy dispersive spectroscopy (EDS). The statistical study is based on the failure history of some 53 hollow-profile dies in which the effect of billet quality on various measurable process parameters including extrusion ratio, billet temperature, exit temperature and repeated nitriding is analysed and related with useful die service life. Comparatively coarse grain structure, non-homogeneous distribution of secondary phases, and high hardness in the case of secondary billet were found responsible for poor die performance as observed in statistical investigation of failed dies. Two types of regression models are also proposed for prediction of die life in terms of secondary billets’ usage and measurable influencing parameters. Using current results, some suggestions during in-house billet preparation of secondary billets have been devised for improved die life.

Development of arc welding technique to preclude microsegregation in the dissimilar joint of Alloy C-2000 and C-276

2021 ◽  
pp. 095440892110000
Author(s):  
B Arulmurugan ◽  
M Sathishkumar ◽  
D Balaji ◽  
K Muralikrishnan ◽  
S Pranesh ◽  
...  
Keyword(s):  
Charpy Impact ◽  
Hardness Test ◽  
Xrd Analysis ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Structure Property ◽  
X Ray ◽  
Dissimilar Weld ◽  
Dissimilar Alloys ◽  
Average Grain Size

Hastelloy C-2000 and C-276 are widely used in Flue Gas Desulphurization (FGD) system and Chemical Processing Industries (CPI). Current work is focused on weld microstructure, and mechanical properties (structure-property relationship) of the dissimilar combination of alloy C-2000 and C-276. Multi-pass Pulsed Current Gas Tungsten Arc (PCGTA) welding was adopted for joining the dissimilar alloys using the filler ERNiCrMo-17. Microstructural characteristics of the weld joint were assessed by Optical and Scanning Electron Microscope (SEM). Weld interface microstructure examination revealed the presence of grain coarsening near the Heat Affecting Zone (HAZ) of the alloy C-276 side. SEM analysis shows the absence of secondary Topologically Closed Packed (TCP) phases in the Inter-Dendritic (ID) regions of the dissimilar weld. Micro-segregation of alloying elements in the weldment was assessed by Energy-Dispersive X-ray Spectroscopy (EDS). X-Ray Diffraction (XRD) analysis had been carried out to identify the phase constitution and average grain size. Strength, toughness, and hardness of the dissimilar weld were evaluated with the support of the tensile test, Charpy impact test, and Vicker’s hardness test. Tensile study showed that all the tensile fracture occurred at the base metal side of alloy C-276. The average toughness of the dissimilar alloy joint was noted about 84 J. Hardness test results indicated that fusion zone (FZ) hardness value was 6.19% and 2.27% superior to the candidates’ material (C-276 and C-2000) employed in this study. The refined grain structure and absence of microsegregation resulted in the highest hardness in the dissimilar weld FZ. Results revealed the substantiated use of PCGTA welding for the effective joining of dissimilar alloys of C-2000 and C-276 through the evaluation of metallurgical and mechanical characteristics.

scholarly journals The Valance Determination of Cerium Ions in α-SiAlON by Electron Energy Loss Spectroscopy Analysis

2008 ◽  
Vol 14 (S3) ◽  
pp. 19-22 ◽  
Author(s):  
H. Yurdakul ◽  
S. Turan
Keyword(s):  
Rare Earth ◽  
Ionic Radius ◽  
High Hardness ◽  
Engineering Properties ◽  
Secondary Phases ◽  
Sintering Additive ◽  
Valence States ◽  
Domain Boundaries ◽  
Spark Plasma

SiAlON ceramics have found applications in many different areas due to their excellent engineering properties such as high hardness, fracture toughness, good thermal shock and oxidation resistance. SiAlON exist mainly in two different polymorphs: a (MxSi12-(m+n)Al(m+n)OnN16-n; M: metal and rare earth cations, x≈0,35 and n≤1,35) and β (β-Si6-zAlzOzN8-z; 0≤z≤4). In general, stable alpha and beta phases separately as well as in combination of α and β are obtained by incorporation of metal and rare earth cations as sintering additives. The metal cations such as Li, Mg, Ca, Y, and most lanthanide cations with the exception of La, Ce, Pr and Eu are able to stabilise α-SiAlON structure. Ekstrom et al. 1991 found that cerium can not occupy interstitial sites in α-SiAlON structure due to the fact that ionic radius of Ce3+ (0.103 nm) is too large, whereas ionic radius of Ce4+ (0.080 nm) is too small to stabilise α-SiAlON structure. After this work, several studies carried out to incorporate cerium cations into α-SiAlON structure. It was shown that cerium cation alone can be incorporated into α-SiAlON if the samples are either fast cooled after sintering, or when the samples are spark plasma sintered. On the other hand, cerium can also be incorporated into the α-SiAlON structure when it is used as a sintering additive together with a smaller α-SiAlON stabiliser cation such as Yb or Ca. Similar results were observed in other multi-cation doped SiAlONS that non α-SiAlON stabiliser cations like Sr2+ (0.112 nm) and La3+ (0.106 nm) are able to stabilise α-SiAlON when used together with α-SiAlON stabiliser cations such as Ca or Yb. Although it was shown that cerium existed in mixed valance state at domain boundaries in Ce-doped and spark plasma sintered α-SiAlON, there is no work on the valance determination of cerium in sintered α-SiAlON which has no domain boundaries. Therefore, in this study; it was aimed to incorporate cerium into α-SiAlON structure by combining with Yb3+ and the determination of possible cerium valence states (Ce3+/Ce4+) in both α-SiAlON grains and secondary phases.

Depth Profile of Structure, Strain, and Composition in an Annealed Al-Cu-Fe-Cr Quasicrystalline Film

2001 ◽  
Vol 695 ◽  
Author(s):  
M.J. Daniels ◽  
D. King ◽  
J.S. Zabinski ◽  
Z.U. Rek ◽  
J.C. Bilello
Keyword(s):  
Residual Strain ◽  
Incident Angle ◽  
Rf Sputtering ◽  
Strain Analysis ◽  
Grazing Incidence ◽  
Grain Structure ◽  
Second Phase ◽  
Secondary Phases ◽  
Composite Target ◽  
X Ray

ABSTRACTQuasicrystalline films were formed by RF sputtering from a powder composite target onto Inconel substrates, which produces a polymorphic nanoquasicrystalline grain structure, ~2.5 - 10 nm. Subsequent annealing at 500°C for 4 hours, at base pressures of below 5*10-5 Torr, and with Ar flow to 5 - 10 mT, fully develops the quasicrystalline structure with decagonal phase predominating, except near the termination surface. Analysis by XPS indicated extensive oxygen incorporation and limited aluminum enrichment at the termination surface. These results are correlated with structure and strain analysis via synchrotron grazing incidence x-ray scattering (GIXS). By varying the incident angle, hence the x-ray penetration depth, the evolution of an amorphous and crystalline crystalline secondary phases at the surface of the film has been detected. Residual strain analysis shows that this second phase induces a compressive residual strain of 0.10% as measured from the displacement of the major quasicrystalline peaks in the surface layers of the film.

scholarly journals Subsolidus solution and ionic conductivity of rock-salt structured Li3+5xTa1−xO4 electroceramics

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
S. Shari ◽  
K.B. Tan ◽  
C.C. Khaw ◽  
Z. Zainal ◽  
O.J. Lee ◽  
...  
Keyword(s):  
Rock Salt ◽  
Xrd Analysis ◽  
Secondary Phases ◽  
Ionic Conductors ◽  
Rock Salt Structure ◽  
Conventional Solid State Reaction ◽  
Salt Structure ◽  
Crystallite Sizes ◽  
Symmetry Space ◽  
Symmetry Space Group

AbstractLithium tantalate solid solution, Li3+5xTa1−xO4 was prepared by conventional solid-state reaction at 925 °C for 48 h. The XRD analysis confirmed that these materials crystallized in a monoclinic symmetry, space group C2/C and Z = 8, which was similar to the reported International Crystal Database (ICDD), No. 98-006-7675. The host structure, β-Li3TaO4 had a rock-salt structure with a cationic order of Li+:Ta5+ = 3:1 over the octahedral sites. A rather narrow subsolidus solution range, i.e. Li3+5xTa1−xO4 (0 ⩽ x ⩽ 0.059) was determined and the formation mechanism was proposed as a replacement of Ta5+ by excessive Li+, i.e. Ta5+ ↔ 5Li+. Both Scherrer and Williamson-Hall (W-H) methods indicated the average crystallite sizes in the range of 31 nm to 51 nm. Two secondary phases, Li4TaO4:5 and LiTaO3 were observed at x = 0.070 and x = −0:013, respectively. These materials were moderate lithium ionic conductors with the highest conductivity of ~2.5 × 10−3 Ω 1 ˙cm−1 at x = 0, at 0 °C and 850 °C; the activation energies were found in the range of 0.63 eV to 0.68 eV.

scholarly journals The effects of calcination and doping on structural and dielectric properties of CaCu3-xCoxTi4O12 ceramic

2019 ◽  
Vol 8 (3) ◽  
pp. 234
Author(s):  
Nasr Hadi ◽  
Tajdine Lamcharfi ◽  
Farid Abdi ◽  
Nor-Said Echtoui ◽  
Ahmed Harrach ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Xrd Analysis ◽  
Secondary Phases ◽  
Solid State Method ◽  
Complex Impedance Analysis ◽  
Oxide Powders ◽  
Increasing Temperature

<p class="Abstract"><span lang="EN-US">The influences of calcination temperature and doping with cobalt in A–site on structural and dielectric properties of CaCu<sub>3-x</sub>Co<sub>x</sub>Ti<sub>4</sub>O<sub>12</sub> (CCCxTO, x = 0.00, 0.02 and 0.10) ceramics sintered at 1050 <sup>0</sup>C for 8h were investigated. The ceramic samples are prepared by the conventional solid-state method using high purity oxide powders, and they are calcined at 850 °C, 950 °C and 1050 <sup>0</sup>C for 4h. The X-ray diffraction (XRD) analysis of pure and doped CCTO samples calcined at 950 °C and 1050 <sup>0</sup>C showed no traces of any other secondary phases, while impurity phases alongside CCTO phase in the x=0.00 sample calcined at 850 <sup>0</sup>C was observed. Scanning electron microscopy (SEM) investigation showed an increase in grain size with increasing of Co content and calcining temperature. Dielectric measurements indicated that the dielectric constant of the pure CCTO calcined at 1050 <sup>0</sup>C/4h has a low value in the frequency range of 1kHz up to 1MHz, whereas the substitution of Co up to x = 0.10 into CCTO caused a huge increase in the dielectric constant value of the calcined samples which is equal to 153419 and 18957 at 950 <sup>°</sup>C and 1050 <sup>0</sup>C respectively. The complex impedance analysis of all samples shows a decrease in resistance with an increasing temperature, which suggests a semiconductor nature of the samples.</span></p>

scholarly journals Analysis and optimization of cooling channels performances for industrial extrusion dies

2021 ◽  
Author(s):  
Riccardo Pelacci ◽  
Marco Negozio ◽  
Barbara Reggiani ◽  
Lorenzo Donati ◽  
Luca Tomesani
Keyword(s):  
Liquid Nitrogen ◽  
Numerical Models ◽  
Extrusion Process ◽  
Die Design ◽  
Design Stage ◽  
Fe Model ◽  
Cooling Efficiency ◽  
Channel Design ◽  
Liquid Nitrogen Cooling ◽  
Experimental Trials

Liquid nitrogen cooling is widely used in the extrusion industrial practice in order to increase the production rate, to reduce the die temperature and to avoid defects on the profile exit surfaces resulting from an excessive heating. However, the efficiency of the cooling is deeply affected by position and design of the liquid nitrogen channel so that numerical modelling is gaining an increasing industrial interest in relation to the possibility offered to optimize the channel design without expensive and time-consuming experimental trials. In this work, a numerical FE model developed within COMSOL Multiphysics® is proposed and validated against experimental trials performed in industrial environment. The model combines the 3D simulation of the extrusion process with a 1D model of the cooling channel thus allowing the testing of a number of different solutions at the die design stage. The global aim of this work is the assessment of the liquid nitrogen cooling efficiency in the extrusion of an industrial aluminum profile and the proof of the potentials offered by numerical models to get an optimized channel design in terms of cooling efficiency, die thermal balancing and reduction of liquid nitrogen consumption.

Wear Studies of Al2O3-ZrO2∙5CaO Composite Coatings for Tribological Applications

2018 ◽  
Vol 7 (3.4) ◽  
pp. 73
Author(s):  
Abhinav . ◽  
N Krishnamurthy ◽  
Ranjana Jain
Keyword(s):  
Composite Coatings ◽  
Spray Coating ◽  
High Hardness ◽  
Xrd Analysis ◽  
Atmospheric Plasma ◽  
Crystallographic Structure ◽  
The Coefficient Of Friction ◽  
Sem Micrograph ◽  
Composite Mixture ◽  
Pin On Disk

A composite mixture of Metco 105 SFP, 99.9% Al2O3 and Metco 201 NS, ZrO2.5CaO were blended in the pursuit of high hardness and improved wear resistance characteristics for tribological applications. In this context a composite mixture of alumina and calcia stabilized zirconia in 50:50 by wt. % proportion was developed, and applied over Al-6061 substrates. Atmospheric plasma spray coating technique was used to develop the coating systems. The ASTM G132 standard, a pin-on-disk tribometer was used to determine the specific wear rate at different normal loads of 5 N, 10 N and 15 N. Experimental results revealed that the top coat primarily subjected to sliding and localized abrasion and also confirmed with SEM micrograph. Sliding has mainly occurs in the plane of <111>, <200>, <220>, <311>, <222> found in the XRD analysis. Irrespective of the applied normal loads the coefficient of friction doesn’t influences much in the abrasive wear studies. However, wear mechanism was found to primarily dependent on the phases and on the crystallographic structure of the material used.  

Structural Characteristic and Dielectric Properties of Zirconia Toughened Alumina

2020 ◽  
Vol 1010 ◽  
pp. 250-255
Author(s):  
Nik Akmar Rejab ◽  
Nurul Khairunnisa Su ◽  
Wan Fahmin Faiz Wan Ali ◽  
Mohd Fadzil Ain ◽  
Zainal Arifin Ahmad ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Dielectric Resonator ◽  
Cutting Tool ◽  
High Hardness ◽  
Xrd Analysis ◽  
Dielectric Resonator Antenna ◽  
Frequency Range ◽  
Band Frequency ◽  
X Band ◽  
Zirconia Toughened Alumina

Zirconia toughened alumina (ZTA) has shown a great effect in the cutting tool application due to its high hardness and comparable fracture toughness. However, the capability of the materials to be applied in as the dielectric resonator antenna (DRA) is not being discussed in detail. In this study, an attempt is made to further explore the potential of ZTA to be applied in DRA. Various related characterization techniques were applied that is subjected to DRA properties. The addition of CeO2 (0 wt.% to 15 wt.%) on ZTA has been pressed into pellets shape and sintered at 1600 °C for 2 hours under pressureless conditions. Based on the XRD analysis, only corundum and yttria doped zirconia phases were present. Shift in position of the zirconia peaks was observed due to an existence of Ce2Zr3O10 phase. For the DRA measurement, ZTA with 10 wt.% CeO2 addition have resonated at 6.76 GHz which is suitable for X-band applications. Meanwhile the radiation pattern indicated the omnidirectional characteristic, which suggested that the signal could be received by this dielectric antenna in various positions. Therefore, ZTA- 10 wt.% CeO2 have high potential to be used as DRA that operates X-band frequency range applications.

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