Casting and Heat Treatment of Turbocharger Impellers Thixocast from Alloy 201

2012 ◽  
Vol 192-193 ◽  
pp. 556-561 ◽  
Author(s):  
Qiang Zhu ◽  
Stephen Midson ◽  
Chang Wei Ming ◽  
Helen V. Atkinson
Keyword(s):  
Heat Treatment ◽  
High Strength ◽  
Heat Treatment Condition ◽  
Hot Tearing ◽  
Alloy Casting ◽  
Heat Treated ◽  
Before And After ◽  
Optimum Heat ◽  
Semi Solid ◽  
Optimum Heat Treatment

Commercial semi-solid cast impellers are produced from Al-Si-Cu alloys heat treated to the T6 temper. The study described in this paper involved the identification of casting and heat treatment parameters to produce semi-solid processed turbocharger impellers from a silicon-free, higher strength 201 alloy. Casting parameters were identified which minimized hot tearing in the alloy 201 impellers. A series of heat treatment studies were performed to determine optimum heat treatment parameters. The T71 temper was identified as the preferred heat treatment condition to produce high strength as well as superior elongation. The results from mechanical property measurements conducted on the T71 heat treated impellers are reported. Optical and scanning electron microscopy (SEM) were also used to characterize the microstructure of alloy 201 impellers before and after heat treatment, and representative microstructures are presented.

Failure analysis of heat treated HSLA wheel bolt steels

2010 ◽  
Vol 6 (3) ◽  
pp. 373-382
Author(s):  
Ali Nazari ◽  
Shadi Riahi
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Failure Analysis ◽  
Heat Treating ◽  
Boron Steel ◽  
Content Type ◽  
Heat Treated ◽  
Before And After ◽  
Molybdenum Steel ◽  
Optimum Heat

PurposeThe aims of this study is to analyze failure of two types of high‐strength low‐alloy (HSLA) steels which are used in wheel bolts 10.9 grade, boron steel and chromium‐molybdenum steel, before and after heat treatment.Design/methodology/approachThe optimum heat treatment to obtain the best tensile behavior was determined and Charpy impact and Rockwell hardness tests were performed on the two steel types before and after the optimum heat treating.FindingsFractographic studies show a ductile fracture for heat‐treated boron steel while indicate a semi‐brittle fracture for heat‐treated chromium‐molybdenum steel. Formation of a small boron carbide amount during heat treating of boron steel results in increment the bolt's tensile strength while the ductility did not changed significantly. In the other hand, formation of chromium and molybdenum carbides during heat treating of chromium‐molybdenum steel increased the bolt's tensile strength with a considerable reduction in the final ductility.Originality/valueThis paper evaluates failure analysis of HSLA wheel bolt steels and compares their microstructure before and after the loading regime.

The Effect of Semi-Solid Parameters on the Microstructure and Hardness of High Chromium Cast Irons

2010 ◽  
Vol 457 ◽  
pp. 84-89 ◽  
Author(s):  
Arash Inanlou ◽  
S. Hossein Seyedein ◽  
M. Reza Aboutalebi
Keyword(s):  
Heat Treatment ◽  
Casting Process ◽  
Cast Irons ◽  
Inclined Plate ◽  
Cooling Plate ◽  
High Chromium ◽  
Primary Austenite ◽  
Heat Treated ◽  
Before And After ◽  
Semi Solid

High chromium cast iron samples of 14% Cr and 24% Cr were produced in sand and permanent mold using semi-solid casting process. A series of experiments were carried out to clarify the effect of copper cooling plate and mold cooling rate on microstructure, particularly morphology and sphericity of primary austenite, hardness and heat treatment cycles. Results show that for 14% Cr and 24% cast irons casting at 10 and 15 degrees of inclined plate result in better sphericity and distribution of primary austenite and carbides. Moreover hardness comparison of both semi-solid iron alloys using copper cooling plate at of this special morphologies resulted from cooling plate investigated by making them heat treat at 1050 centigrade °C for 1 and 2 hours. Hardness results show both heat treated 14 and 24% Cr alloy in 1 hours have hardness comparable with those alloys traditionally cast optimum angles with respect to conventional casting show higher hardness in every condition. Effect but heat treated in 2 hours. Finally X-Ray diffraction pattern taken from specimens before and after heat treatment confirmed with observed phases in optical microscopy before and after heat treatment.

Failure Analysis and Study on Heat Treatment Process of Grate Bars Used in Sintering Trolley

2014 ◽  
Vol 1061-1062 ◽  
pp. 454-459
Author(s):  
An Min Li ◽  
Ding Ma ◽  
Qi Feng Zheng ◽  
Ruo Huai Chen ◽  
Qiang Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Residual Austenite ◽  
Shrinkage Porosity ◽  
Heat Treatment Process ◽  
Fracture Characteristics ◽  
Heat Treated ◽  
Primary Means ◽  
Optimum Heat ◽  
Optimum Heat Treatment

The as-cast grate bar structure used in sintering trolley is primarily comprised of austenite and eutectic (eutectic austenite and eutectic carbide).The austenite is dendrite, while the carbides are reticular and chrysanthemum-like. The failed grate bar structure primarily consists of ferrite, carbide, martensite and residual austenite; cavity shrinkage and shrinkage porosity exist in the structure, and the fracture exhibits typical cleavage fracture characteristics. The primary means of failure are abrasion and fracture. The secondary carbides precipitated in the sample (quenching (1050°C+2.5h)+ tempering (390°C+2.5h)) and the other one (quenching (1050°C+2.5h)+ tempering (420°C+2.5h) ) are dispersed and refined. Compared with the as-cast one, their relative abrasion resistance performances respectively are 0.8645 and 0.8752.The values of hardness and impact toughness of the samples heat-treated are greater than those of the as-cast grate bar. The optimum heat treatment process is as follows: quenching (1050°C,2.5h) + tempering (390°C~420°C,2.5h)

The Effect of Heat Treatment on Formability of Ultra-Fine Grained AA6061 for Bolt Manufacturing

2010 ◽  
Vol 443 ◽  
pp. 164-169 ◽  
Author(s):  
Jun Seok Choi ◽  
Young Gwan Jin ◽  
Yong Taek Im
Keyword(s):  
Heat Treatment ◽  
Artificial Aging ◽  
Equal Channel Angular Extrusion ◽  
High Strength ◽  
Strength Increase ◽  
Fine Grained ◽  
Heat Treated ◽  
Before And After ◽  
Fine Grained Material ◽  
Set Up

Equal channel angular extrusion (ECAE) was used before and after artificial aging to investigate the effect of heat treatment on formability of bulk nanostructure of commercially available aluminum alloy of AA6061 in the present study. In the ECAE, route A was applied up to four or eight passes by using the split dies set-up. The three-stage bolt forming using the ultra-fine grained specimens was carried out to check formability of the material. In the present experiments, the bolt forming was successful with the specimen prepared by the ECAE after artificial aging whilst it was not successful with the specimen prepared by a reverse process sequence. The strength increase was confirmed by the tension and microhardness tests and compared to the result of conventional AA2024 bolt made by the conventionally heat treated specimen. It was found that the strength was comparable to the level of the heat treated conventional one although the actual value was a little bit lower. In addition, it was demonstrated that the heat treatment sequence is important to achieve proper formability of the ultra-fine grained material to manufacture the high strength bolt.

Fabrication of Bi2Sr2CaCu2O8 Superconductor Thick Films on Cu Substrates

2000 ◽  
Vol 623 ◽  
Author(s):  
Sang-Chul Han ◽  
Tae-Hyun Sung ◽  
Young-Hee Han ◽  
Jun-Seong Lee ◽  
Sang-Joon Kim
Keyword(s):  
Heat Treatment ◽  
Thick Films ◽  
Heat Treatment Condition ◽  
Treatment Temperature ◽  
Molten State ◽  
Liquid Reaction ◽  
Heat Treated ◽  
Cu Substrates ◽  
Optimum Heat ◽  
Precursor Composition

AbstractWell oriented Bi2Sr2CaCu2O8(Bi2212) superconductor thick films were formed successfully on Cu tapes by liquid reaction between Cu-free precursors and Cu tapes. Cu-free Bi-Sr-Ca-O powder mixtures were screen-printed on Cu tapes and heat-treated at 850-870°C for several minutes in air. Cu-free precursors were composed of BixSrCaOy(x= 1.2-2). In order to obtain the optimum heat-treatment condition, we studied on effects of the precursor composition, heattreatment temperature and time, the screen-printing thickness, and the heat-treatment atmosphere on the superconducting properties of Bi2212 films. Microstructures and phases of films were analyzed by XRD and optical microscopy. The electric properties of superconducting films were examined by the four probe method. At heat-treatment temperature, the specimens were in a partially molten state by liquid reaction between CuO in the oxidized copper tape and the precursors. The non-superconducting phases in the molten state are mixtures of Bi-free phase and Cu-free phases.

scholarly journals Hydrogen Embrittlement of the Additively Manufactured High-Strength X3NiCoMoTi 18-9-5 Maraging Steel

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5073
Author(s):  
Angelina Strakosova ◽  
Michaela Roudnická ◽  
Ondřej Ekrt ◽  
Dalibor Vojtěch ◽  
Alena Michalcová
Keyword(s):  
Heat Treatment ◽  
Hydrogen Embrittlement ◽  
Maraging Steel ◽  
Tensile Testing ◽  
High Strength ◽  
Fracture Surface Morphology ◽  
Laser Melting ◽  
Heat Treated ◽  
Before And After ◽  
A Current

The main aim of this study was to determine the susceptibility of the additively manufactured high strength X3NiCoMoTi 18-9-5 maraging steel to hydrogen embrittlement. For this purpose, samples produced by selective laser melting technology, before and after heat treatment, were used. The examined samples were electrochemically charged with hydrogen in NaCl + NH4SCN solution at a current density of 50 mA/cm2 for 24 h. The H content increased from about 1 to 15 ppm. Heat treatment did not affect the amount of H trapped in the maraging steel. Tensile testing revealed that the tensile strength of the H-charged samples was much lower than that of the uncharged samples. Moreover, the material became brittle after charging compared to the ductile as-printed and heat-treated samples with elongation values of 7% and 2%, respectively. The loss of plasticity was confirmed by fractography, which revealed transformation of the fracture surface morphology from dimple-like in the as-produced state to a brittle one with smooth facets in the H-charged state.

Optimum heat treatment condition for PZT thin films prepared by Sol-Gel

1999 ◽  
Vol 232 (1) ◽  
pp. 65-70
Author(s):  
Ai-Li Ding ◽  
Wel-Gen Luo ◽  
Pingsun Qiu ◽  
Kwang Soo No
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Treatment Condition ◽  
Sol Gel ◽  
Heat Treatment Condition ◽  
Pzt Thin Films ◽  
Optimum Heat ◽  
Optimum Heat Treatment

Comparison of Microstructure and Mechanical Properties of Additively Manufactured and Conventional Maraging Steel

2020 ◽  
Vol 405 ◽  
pp. 133-138
Author(s):  
Ludmila Kučerová ◽  
Andrea Jandová ◽  
Ivana Zetková
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Precipitation Hardening ◽  
High Strength ◽  
Hardness Measurement ◽  
Nickel Steel ◽  
Heat Treated ◽  
Good Material ◽  
Iron Nickel

Maraging steel is an iron-nickel steel alloy, which achieves very good material properties like high toughness, hardness, good weldability, high strength and dimensional stability during heat treatment. In this work, maraging steel 18Ni-300 was manufactured by selective laser melting. It is a method of additive manufacturing (AM) technology, which produces prototypes and functional parts. Sample of additively manufactured and conventional steel with the same chemical composition were tested after in three different states – heat treated (as-built/as-received), solution annealed and precipitation hardened. Resulting microstructures were analysed by light and scanning electron microscopy and mechanical properties were obtained by hardness measurement and tensile test. Cellular martensitic microstructures were observed in additively manufactured samples and conventional maraging steel consisted of lath martensitic microstructures. Very similar mechanical properties were obtained for both steels after the application of the same heat treatment. Ultimate tensile strengths reached 839 – 900 MPa for samples without heat treatment and heat treated by solution annealing, the samples after precipitation hardening had tensile strengths of 1577 – 1711 MPa.

scholarly journals Study on the Properties of Transparent Bamboo Prepared by Epoxy Resin Impregnation

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 863 ◽  
Author(s):  
Yan Wu ◽  
Yajing Wang ◽  
Feng Yang ◽  
Jing Wang ◽  
Xuehua Wang
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Visible Light ◽  
Epoxy Resin ◽  
Raw Materials ◽  
Light Transmittance ◽  
Advantages And Disadvantages ◽  
Heat Treated ◽  
Before And After ◽  
Different Parts

In this paper, Moso bamboo (Phyllostachys heterocycle) before and after heat treatment were used as raw materials to prepare transparent bamboo (TB). In an acidic environment, the lignin contained in the bamboo material was removed to obtain a bamboo template, and an epoxy resin similar to the cellulose refractive index was used for vacuum impregnation into the bamboo template to obtain a transparent bamboo material. The purpose of this study was to compare the physical and chemical properties of TB and original bamboo and the differences between TBs before and after heat treatment, taken from different parts of bamboo, in order to explore the performance advantages and disadvantages of TB as a new material. The Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscope testing (SEM), three elements analysis, light transmittance testing, and mechanical strength testing were used to study the molecular composition, microstructure, chemical composition, light transmittance, and tensile strength of the TB samples. The results showed that the lignin content of the delignified bamboo templates was greatly reduced. In addition, the SEM images showed that a large amount of epoxy resin (type E51 and type B210 curing agent) was covered on the cross-section surface and pores of the TB samples. The FTIR showed that the epoxy molecular groups appeared on the TB, and the delignified bamboo template and the resin had a good synergy effect. According to the light transmittance testing, the original bamboo samples hardly contained light transmittance under visible light. The transmittance of transparent inner bamboo (TIB) and transparent heat-treated inner bamboo (THIB) could reach about 11%, and the transmittance of transparent outer bamboo (TOB) and transparent heat-treated outer bamboo (THOB) was about 2%. The light transmittance had been significantly improved when compared with the original bamboo samples. The transmittances of the TB samples before and after heat treatment in different parts of bamboo were different. In the visible light irradiation range, the light transmittances of TB samples were as follows: TIB > THIB and THOB > TOB. Meanwhile, the tensile strength of TB was reduced, especially for TOB and THOB. In addition, TB has a wide range of raw materials, and the preparation process is environmentally friendly. It can be used for decorative materials in homes, buildings, etc., and has a great application potential.

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