Secondary Cast Research Articles

Improvement of Microstructure and Mechanical Properties of Secondary AlSi8Cu2Mn Cast Alloy by Strontium

Present work is focused on study of the effect of Sr-modification (0 %; 0.03 % and 0.05 %) on the microstructure and mechanical properties of recycled AlSi8Cu2Mn cast alloy. For study and identification of intermetallic phases’ were utilized standard, colour and deep etching in order to reveal the three-dimensional morphology of the silicon particles and intermetallic phases. For element composition of the specimen was used X-ray analysis. Finally, the effect of modification on silicon morphology, mechanical properties (UTS, ductility, hardness and impact energy) was examined.The results show that the addition of Sr into AlSi8Cu2Mn cast alloy should act as a modifier, so it supposes to change the eutectic Si-morphology. However, its effect as a Si-modifier is not as significant as we have expected. Strontium refined and changed morphology of Si and thereby improves mechanical properties, first of all ductility and impact energy.

A Skinful of Shadows by Frances Hardinge

Reviewed by: A Skinful of Shadows by Frances Hardinge Kate Quealy-Gainer Hardinge, Frances A Skinful of Shadows. Amulet, 2017 [432p] Trade ed. ISBN 978-1-4197-2572-2 $19.99 E-book ed. ISBN 978-1-68335-106-1 $15.54 Reviewed from galleys R Gr. 6-9 As an illegitimate child of the Fellmotte family, twelve-year-old Makepeace has inherited their ability to share minds and bodies with ghosts. Generations of Fellmottes have been kept "alive" this way, as one ancestor dies and pours their spirit—and the other spirits they might be holding—into one of the younger family members. Makepeace is expected to do her duty as the spare vessel when an Elder, holding seven spirits, dies, but she refuses, and Bear, the spirit of an animal that she inadvertently "collected," manages to thwart the ghostly interlopers before they crush Makepeace's mind. Soon she's fleeing across an English countryside battered by the English Civil War and trying to escape the Fellmottes, all while learning to control her ability and actively selecting the ghosts she allows to take residence in her mind. The book starts on an intensely creepy note, with Makepeace violently haunted by spirits that want to enter her, but the horrors are all in service of a more coming-of-age character arc, as Makepeace grapples with her gift/curse and what it means for her place in the world and her future. The ghosts that eventually inhabit Makepeace's mind (by her choice) make a superb secondary cast: Bear serves as the warm protector Makepeace never had; the doctor is wickedly funny; the soldier brings to the forefront the emotional toil war brings; and finally, a shadowy spirit forces her to reckon with her mother's death. The setting allows for plenty of action and intrigue, as Makepeace manipulates the Fellmottes and their Royalist leanings to her advantage. It all ends on a strange and bittersweet note, but Hardinge fans will be accustomed to that by now and will not be disappointed here. KQG [End Page 161] Copyright © 2017 Board of Trustees of the University of Illinois

Study on the impact of labro-chondral complex on development of the acetabulum after close reduction in developmental dysplasia of the hip

Objective: To explore the influence of the labro-chondral complex (LLC) on the development of the acetabulum after close reduction in developmental dysplasia of the hip (DDH). Methods: Sixty-one cases (72 hips) with DDH presented in Beijing Jishuitan Hospital were reviewed, all the patients were treated by closed reduction, arthrogram and Spica casting from March 2010 to December 2013. The anterior-posterior pelvic radiography was performed to evaluate the morphology of the labro-chondral complex and reduction of the hip. The cases were divided into Ⅰ, Ⅱ, Ⅲ, Ⅳ four groups according to the shape of the LLC initially, and when performed the secondary Spica cast after 3 months, these cases were divided into 0-0.4, 0.4-0.6, and >0.6, three groups based on the height difference ratio (HDR) of the LLC. The relationship between the shape and HDR of the LLC was analyzed. The AI and CE angle were used to evaluate development of the hip during the latest follow up. The impact of the shape and HDR of the LLC on the development of the acetabulum was explored as well. Results: The HDR was the least in the type Ⅰ hips, all cases were less than 0.6, the AI in this group was significantly lower than the others(24.33°±3.12°), and the CE angle was significantly higher in the type Ⅰ hips(15.22°±3.11°) during the latest follow up. The CE angle was significantly different among the three groups of HDR. The HDR was lower, the CE angle was higher. The AI in 0-0.4 group was significantly lower than the others(14.24°±3.10°). Conclusion: The shape of the LLC is helpful to judge development of the acetabulum when closed reduction was performed in DDH. And the HDR in the secondary cast change could be used as a sensitive index to predict development of the hip.

Fractography Evaluation of Fracture Surfaces of Aluminium Alloy After Fatigue Tests

Secondary cast alloy AlZn10Si8Mg (UNIFONT-90) is generally used for engine and automotive constructions, hydraulic unit and mold making without any additional heat treatment. It has good properties such as castability, very good mechanical strength, light weight, good wear resistance and very good machining. At present, one of the main limits to a wide use of aluminium alloys for engine or automotive applications is a lack of complete understanding of their fatigue behaviour and of the relationships to microstructural features, particularly as far as casting alloys are concerned.Fatigue properties of AlZn10Si8Mg cast alloy in the high-cycle cycle region were tested by rotating bending fatigue loading with the used of parameters - frequency f = 40 Hz, temperature T = 20 ± 5 ℃ and stress ratio R = -1. Numerous studies shown those cast aluminium alloys are very sensitive to casting defects as porosity and microshrinkages and whenever large pore is present at or near the specimen's surface, it will be the dominant cause of fatigue crack initiation.

Decreasing Defects of Center Porosity and Improving Secondary Pipe Castings for Superalloy Ingots by Dynamics Methods

The causes and the influence factors of the defects of center porosity and secondary pipe of the casting superalloy ingot are briefly introduced, and the study on the principle and technical characters of grain refinement technology with dynamic methods carried out. The mechanism, working parameter and the test result of the typical application methods including the technologies of vibration of ultrasonic, the vibration of mould, the stir of mould and oscillation in the riser were investigated in detail. By comparing the advantages and disadvantages of different methods and also according to the practical production situation of our company, the most appropriate one for improving the defects of center porosity and secondary pipe is proposed.

Wirewalker by Mary Lou Hall

Reviewed by: Wirewalker by Mary Lou Hall Elizabeth Bush Hall, Mary Lou Wirewalker. Viking, 2016 [304p] ISBN 978-0-670-01646-4 $17.99 Reviewed from galleys R Gr. 7-10 When Y, a local drug dealer and runner of dogfights, offers fourteen-year-old Clarence the opportunity to run drugs for his operation, Clarence is game. He’s sick of watching his dad (who is white) drown in drink since Clarence’s mom (who was African American) was murdered several years ago, sick of being called Itty for his size, sick of seeing a future with no respect, so he takes the deal, undergoing initiation to become a Y-Boy. He’s committed, though, to walking the fine line between surviving the rough streets and becoming the respectable man his mother had raised him to be, to be a force of good like the superheroes he so admires. And he might just do it. Besides being a good student, Clarence has Mr. Khabir, owner of the Kwik-Bi, and Ms. Angelique Moffet, his English teacher, to support and guide him. Mona, a Great Dane that’s caught Y’s attention as a possible competitor at his illegal dog fights, and Billie, a foul-mouthed, abused sixth-grader Clarence has agreed to mentor, both give his life some purpose (and inspire his imaginary superhero persona of Wirewalker). Debut novelist Hall paces her story patiently, allowing each questionable decision Clarence makes to increase the dramatic tension, while quietly raising the stakes for the secondary cast—human and canine—as well. There’s grit and challenging honesty here to serve readers who are not quite ready for full-out Urban Lit. By story’s end, Clarence is simply relieved to be reconnected with his father and out of Y’s organization, but readers will recognize his change of direction as the superheroic act he always hoped Wirewalker would accomplish. Copyright © 2016 The Board of Trustees of the University of Illinois

Modified ventricular puncture combined with urokinase in the treatment of secondary intraventricular cast hemorrhage

We introduce a new catheter-based minimally invasive approach via frontal tuber for removing hypertensive intraventricular hemorrhage(IVH), and further compare its treatment efficacy with conventional external ventricular drainage (EVD). This study is prospective and randomized. Sixty cases of secondary intraventricular cast hemorrhage patients were randomly divided into two groups of 30 cases: modified ventricular puncture (MVP) group and control group. Preoperative Glasgow coma scale (GCS) and Graeb score were compared between the two groups. The postoperative manifestations of two groups were also analyzed and compared statistically, including evacuation rate of intraventricular hematoma in 24 h, the time with drainage tube, rebleeding, complicated by infection, shunt-dependent hydrocephalus and Glasgow outcome scale at 3 months. 1. There was no significant difference in preoperative GCS score and the Graeb score between two groups (P > 0.05). 2. In the MVP group via frontal tuber approach, a substantial removal of intraventricular hematoma was achieved in all cases. The average evacuation rate of intraventricular hematoma reached 80.10 ± 10.16 %, the average time of catheter drainage was 3.17 ± 0.87 days, the average GOS was 3.80 ± 0.92, no intracranial infection and secondary hemorrhage were observed following surgery in all cases, and shunt-dependent hydrocephalus occurred in 2 cases. In the control group, the hematoma evacuation rate was an average of 21.21 ± 7.81 %, the time of drainage was an average of 7.63 ± 2.87 days, the GOS was an average of 3.20 ± 1.12, intracranial infection after surgery occurred in 5 cases, secondary hemorrhage was observed in 1 case, and shunt-dependent hydrocephalus occurred in 8 cases. Between the two groups there were significantly statistical difference in the hematoma evacuation rate, drainage duration, infection rate and GOS (all P < 0.05). The new approach is safe, and can quickly remove the hematoma, and significantly shorten the time with a pipe. It can also reduce the occurrence of infection and hydrocephalus, and improve overall outcome of patients, but cannot reduce mortality.

Waiting for Unicorns by Beth Hautala (review)

Reviewed by: Waiting for Unicorns by Beth Hautala Kate Quealy-Gainer Hautala, Beth Waiting for Unicorns. Philomel, 2015 [256p] ISBN 978-0-525-42631-8 $16.99 Reviewed from galleys R Gr. 4-6 In the wake of her mother’s death from cancer, twelve-year-old Talia is forced to spend the summer in the Arctic as her whale-researcher father heads out to study belugas. Churchill, Manitoba, is a small, secluded town, but it’s also the place where her parents met, and Sura, an Inuit friend of Tal’s mom, offers Tal a picture of her mother—young, carefree—that Tal has never seen before. A visiting ornithologist and his grandson also offer some insight and wisdom on grief and loss, and as Tal awaits her father’s return, her emotions thaw with the summer melt and she’s finally ready to close the “Mom-sized space” that has distanced her from her father, who has shut himself off with grief. Tal’s matter-of-fact narration of her mother’s death through flashbacks and memories has a raw simplicity to it, and her pain is evident both in the things she chooses to tell as well those she chooses to omit. While the secondary cast mainly serves as a vehicle for Tal’s healing, her process rings with authenticity—several heart-to-heart talks with her father, for example, are followed by both of them returning to their old, isolating habits, and it’s clear that their recovery will include a realistic amount of fits and starts. Hautala mines the frigid setting for some exquisitely wrought metaphors of sadness and grief, and Tal’s reflections on her situation are lyrical and yet still appropriate, given her age. [End Page 313] Readers who were touched by Holly Goldberg Sloan’s Counting by 7s (BCCB 9/13) will find this to be a similarly moving tale. Copyright © 2015 The Board of Trustees of the University of Illinois

Secondary Al-Si-Mg High-pressure Die Casting Alloys with Enhanced Ductility

Al-Si-Mg-based secondary cast alloys are attractive candidates for thin-walled high-pressure die castings for applications in the transport industry. The present study investigates the effect of manganese additions at high cooling rates on microstructure, mechanical properties, and on the dominating fracture mechanisms of alloy AlSi10Mg with an elevated iron concentration. Systematic variations of the Mn content from 0.20 to 0.85 wt pct at a constant Fe content of 0.55 wt pct illustrate the key changes in type, phase fraction, and shape of the Fe-containing intermetallic phases, and the corresponding influence on the alloy’s ductility. For high-pressure die casting (HPDC), an optimal range of the Mn content between 0.40 and 0.60 wt pct, equivalent to a Mn/Fe ratio of approximately 1, has been identified. At these Mn and Fe contents, the high cooling rates obtained in HPDC result in the formation of fine and homogeneously distributed α-Al15(Fe,Mn)3Si2 phase, and crack initiation is transferred from AlFeSi intermetallics to eutectic silicon. The study interprets the microstructure–property relationship in the light of thermodynamic calculations which reveal a significant increase in undercooling of the α-Al15(Fe,Mn)3Si2 phase with increased Mn content. It concludes that the interdependence of the well-defined Mn/Fe ratio and the high cooling rate in HPDC can generate superior ductility in secondary AlSi10Mg cast alloys.

Optimization of Eutectic Si Particles Morphology in Secondary Al-Si Cast Alloys after Different Heat Treatment

Secondary cast Al-Si alloys containing more of additions elements and forming various structural parameters (intermetallic phases). The optimization of structure parameters morphology is necessary because the mechanical properties depend on changes in morphology of eutectic Si and intermetallic phases in Al-Si cast alloy. This article describes changes of eutectic Si morphology after heat treatment T4 and T6. The morphology changes were observed using combination different analytical techniques - light microscopy (upon black-white etching) and scanning electron microscopy - SEM (upon deep etching). For the experiment was used recycled (secondary) aluminium cast alloy AlSi9Cu3.

Unconventional Metallographic Methods for the Structural Characterization of Laser Hardened Al-Zn-Si Cast Alloy

The laser surface hardening is method which provides increased mechanical properties of secondary (recycled) Al-Si cast alloys for automotive industry. Improvement of mechanical properties and structure of secondary aluminium alloys can often significantly increase the lifetime of casting and reduce costs for fuel and reduction of environmental loading. For study was used a laser beam Nd: YAG lasers, BLS 720, on the test samples of secondary cast alloy AlZn10Si8Mg. AlZn10Si8Mg cast alloy are used for engine and vehicle constructions, hydraulic unit and mould making without the need of heat treatment because this alloy is self-hardened. The effect of laser beam was evaluated with the laser power 50 W and 80 W on the surface of samples. The final microstructure of Al-alloys depend on the laser process parameters. The changes of microstructure after laser surface hardening was observed by using classical techniques of etching (standard black-white contrast - etching by 0.5 % HF, 10 % H3PO4and colour contrast - etching by Weck-Al) and deep etching with HCl. Due to the action of laser beam on the surface of the secondary alloy AlZn10Si8Mg there have been changes in the microstructure of the material. Melting area is alpha-phase with much fine columnar dendrites morphology without the presence of Si-particles and intermetallic phases. In the transition area were observed grain refinement of eutectic Si (finer and rounder Si particles) as the modify action of the laser. By increasing the laser power the microhardness of surface layers decreases. In the surface layer (80 W) were observed cracks due to uneven heat transfer of the material.

Component- and Alloy-Specific Modeling for Evaluating Aluminum Recycling Strategies for Vehicles

Previous studies indicated that the availability of mixed shredded aluminum scrap from end-of-life vehicles (ELV) is likely to surpass the capacity of secondary castings to absorb this type of scrap, which could lead to a scrap surplus unless suitable interventions can be identified and implemented. However, there is a lack of studies analyzing potential solutions to this problem, among others, because of a lack of component- and alloy-specific information in the models. In this study, we developed a dynamic model of aluminum in the global vehicle stock (distinguishing 5 car segments, 14 components, and 7 alloy groups). The forecasts made up to the year 2050 for the demand for vehicle components and alloy groups, for the scrap supply from discarded vehicles, and for the effects of different ELV management options. Furthermore, we used a source-sink diagram to identify alloys that could potentially serve as alternative sinks for the growing scrap supply. Dismantling the relevant components could remove up to two-thirds of the aluminum from the ELV stream. However, the use of these components for alloy-specific recycling is currently limited because of the complex composition of components (mixed material design and applied joining techniques), as well as provisions that practically prevent the production of safety-relevant cast parts from scrap. In addition, dismantling is more difficult for components that are currently penetrating rapidly. Therefore, advanced alloy sorting seems to be a crucial step that needs to be developed over the coming years to avoid a future scrap surplus and prevent negative energy use and emission consequences.

Shadows by Robin McKinley (review)

Reviewed by: Shadows by Robin McKinley Kate Quealy-Gainer McKinley, Robin. Shadows. Paulsen/Penguin, 2013. [368p] ISBN 978-0-399-16579-5 $18.99 Reviewed from galleys R Gr. 7-12 The creeping, tentacled shadows that follow Maggie’s new stepdad around have the seventeen-year-old girl worried. Since she’s the only one who can see them, they might mean that she’s going crazy or, even worse, that she has the ability to see and possibly interact with magic, a big no-no in the science-focused, magic-abolishing state that is Newworld. Before she can decide whether or not to go to the authorities, however, a “cobie,” a cohesion break in Newworld’s reality, sends everyone into a panic, and Maggie discovers that the shadows are actually quiet friendly little critters, her stepdad is an Oldworld magician (and a powerful one at that), and that her magical powers might mean she’s the only one standing between Newworld and its demise. This is a tricky combination of genre tropes—a Big Brother–type of dystopian government, a clueless but powerful savior from fantasy, and the interpersonal dynamics of a family drama—but McKinley crafts them all with a deft hand, spooling out each element with a careful deliberation that allows them to coalesce into a fully formed story. Intricate world building is matched with rich characterization; a bit moody, a bit flighty, and all teenager, Maggie makes a relatable protagonist, and her wisecracks and astute observations help readers gain ground in this eerily familiar but nonetheless complex world of old magic, new science, and breaks in reality. The secondary cast, including the requisite dual love interests, are afforded depth and nuance as well, rounding out the setting for the ensuing emotional drama. Fans of McKinley will recognize her penchant for animal-human connections in Maggie’s affectionate guardianship of the shadows, while other readers will find this a compelling entry point to the author’s work. Copyright © 2013 The Board of Trustees of the University of Illinois

Optical and Scanning Electron Microscope Studies of Recycled (Secondary) Al-Si Cast Alloys

Production of primary Al- alloys belong to heavy source fouling of life environs. Care of environment in industry of aluminium connects with the decreasing consumptions resource as energy, materials, water and soil, with increase recycling and extension life of products. Recycled (secondary) aluminium alloys are made out of Al-scrap and workable Al-garbage by recycling. Applications of these alloys in recent years increase especially in automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Controlling the microstructure of secondary aluminium cast alloy is very important, because these alloy containing more of additions elements, that forming various intermetallic phases in the structure. Improved mechanical properties of secondary alloys are strongly dependent upon the morphologies, type and distribution of the second phases, which are in turn a function of alloy composition and cooling rate. The presence of additional elements as Mg, Mn, Fe or Cu allows many complex intermetallic phases to form, which make characterization non-trivial. A combination of different analytical techniques (light microscopy, scanning electron microscopy (SEM) upon deep etching and energy dispersive X-ray analysis (EDX)) were therefore been used for the various phases identification.

Ultrasonic phased array contribution to the knowledge of the flow fusion welding process used to make the Roman large bronze statues

Recent archeometallurgical studies have shown that Greek and Roman large bronze statues were not cast in one piece, in spite of an exceptional mastering of the lost-wax techniques, but resulted from the welding of several parts previously cast. The ancient welding process proved to be very spectacular: liquid bronze (secondary casting) of the same composition as the base metal (primary casting) was directly poured between the two parts to be joined. We have recently shown that the mechanism involved is similar to the one involved in some modern fusion welding techniques such as arc, laser beam or oxy-fuel, which demonstrates the very high level of knowledge achieved by Greek and Roman foundrymen in the control of high-temperature processes. Twenty-one centuries later, high level of non-destructive testing (NDT) expertise is particularly being needed for archeometallurgical examinations of the statues, not only to describe the welding mechanism, but also to identify several variants of the process (particularly concerning the welding preparation). This paper explains how NDT, and particularly ultrasonic phased array, have brought decisive clues to understand the flow fusion welding process applied to the “Captive Gallic”, a statue found in 2007 during excavation in the Rhone River in Arles (Southern France).

The Broken Lands (review)

Reviewed by: The Broken Lands Kate Quealy-Gainer Milford, Kate . The Broken Lands; illus. by Andrea Offermann. Clarion, 2012. [464p]. Trade ed. ISBN 978-0-547-73966-3 $16.99 E-book ed. ISBN 978-0-547-82266-2 $16.99 Reviewed from galleys R* Gr. 5-9. The Brooklyn Bridge is still under construction in 1877, but its potential to connect two parts of a growing city and its intersection with East River make it a source of great energy—energy that one particularly sadistic entity would like to use to create hell on Earth. Fortunately for the residents of New York, Sam, a streetwise cardsharp, and his hopefully-more-than-just-a-pal Jin, a Chinese immigrant girl who also happens to be a fireworks expert, have cottoned on to the devilish scheme and may just have the power to stop it. First, however, the two friends must identify and find the five pillars of the city, plan and set off a massive fireworks display (which [End Page 103] serves as a public announcement), and deal with their own confusing romantic feelings—all within a couple of days or else the big bad guy is going to win. Much like Bray's The Diviners (reviewed above), this pays tribute to a time and place in U.S. history with vivid detail, capturing both the beauty and the struggle of New York in the late nineteenth century. The backstories of Sam and Jin, along with those of several secondary cast members, add nuance to their characterizations and also imbue the city with a sense of humanity—it is good and bad, gorgeous and flawed all at once. The battle for New York's soul then becomes even more urgent, and the race against the clock makes the four-hundred-plus pages fly by. Though this is a prequel to Milford's debut, The Boneshaker, it requires no knowledge of the other book, and it will be a true delight to fans of history, fantasy, and the triumph of good. Final illustrations not seen. Copyright © 2012 The Board of Trustees of the University of Illinois

Evaluation of the Retention Force of Double Conical Crowns Used in Combination with a Galvanoforming and Casting Fabrication Technique

The aim of this study was to measure the in vitro retention force of double conical crowns fabricated using primary galvanoforming and secondary casting techniques and those fabricated using primary casting and secondary galvanoforming techniques under simulated clinical conditions before and after a wear test. Primary galvanoformed crowns (n = 10) with non-noble secondary crowns (n = 10; group A) and primary non-noble crowns (n = 10) with secondary galvanoformed crowns (n = 10; group B) were fabricated. Each primary and secondary crown was embedded in acrylic resin and weighed with a digital balance. Retention forces were then measured using a universal testing device. To simulate wear, specimens were inserted and separated horizonatally 3285 times in wear equipment with artificial saliva. Retention forces and weights of the double crowns were then remeasured. Data were analyzed using paired t-tests and Wilcoxon tests, and the groups were compared using Mann-Whitney U-tests. In group A, the wear test had a significant influence on the retentive force (p < 0.05), but wear produced no significant difference in weight (p > 0.05). In group B, the wear test had a significant influence on the retentive force (p < 0.05), and wear produced a significant difference in weight (p < 0.05). The results of this study indicated that the use of different combinations of galvanoforming and casting techniques in the fabrication of conical crowns significantly affected retention force.

The Role of Automobiles for the Future of Aluminum Recycling

To reach required product qualities with lowest costs, aluminum postconsumer scrap is currently recycled using strategies of downgrading and dilution, due to difficulties in refining. These strategies depend on a continuous and fast growth of the bottom reservoir of the aluminum downgrading cascade, which is formed by secondary castings, mainly used in automotive applications. A dynamic material flow model for the global vehicle system was developed to assess the likelihood, timing, and extent of a potential scrap surplus. The results demonstrate that a continuation of the above-mentioned strategies will lead to a nonrecyclable scrap surplus by around 2018 ± 5 if no additional measures are taken. The surplus could grow to reach a level of 0.4-2 kg/cap/yr in 2050, corresponding to a loss of energy saving potential of 43-240 TWh/yr electricity. Various intervention options for avoiding scrap surplus are discussed. Effective strategies need to include an immediate and rapid penetration of dramatically improved scrap sorting technologies for end-of-life vehicles and other aluminum applications.

Influence of temperature on certain properties of n +-p and n +-p-p + structures based on secondary cast polycrystalline silicon

This paper discusses the Isc and Uxx temperature dependencies of n+-p and n+-p-p+ structures made of comparatively fine-grained secondary cast polycrystalline silicon upon their being homogenously heating and heated with a temperature gradient, as well as upon alteration of heat flux direction.

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

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.