Download or read book The Effect of Varying Quench Rates and Heating Rates on the Aging Response of an Aluminum Powder Alloy written by Walter M. Griffith and published by . This book was released on 1977 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research examines the effect of varying quench rates and the effect of varying heating rates on the aging response of powder aluminum MA87 alloy. The effect of a six-day room temperature pre-age was also considered. The results obtained are compared with results of similar research on 7075 ingot product and supplemented with electron microscopy. The results indicate little difference in terms of hardness, in the response of MA87 and 7075. This suggests that the quench sensitivity of both alloys is similar and is attributable to the same mechanism. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rapidly Solidified Powder Aluminum Alloys written by Morris E. Fine and published by ASTM International. This book was released on 1986 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of the Quench and Heating Rate Sensitivities of Selected 7000 Series Aluminum Alloys written by and published by . This book was released on 2007 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The quench sensitivity of AA7136 has been experimentally investigated using Jominy end quench and test coupons of various heat treatments. It was found that this alloy is not quench sensitive. In addition, the effects of heating rate on both solution and aging treatments on AA7136 and AA7075 were determined using a newly developed reverse Jominy heating test. It was observed that hardness was reduced after rapid heating during aging and hardness increased slightly after rapid heating during solutionizing. These results are discussed in terms of microstructural developments.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1979-07 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Quenching Rate on Aging Response and Mechanical Properties of Al 7wt Si 0 3Wt Mg Casting Alloy written by Stiliana Raynova and published by . This book was released on 2002 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quench Rate and Aging Effects in Aluminum zinc magnesium copper Aluminum Alloys written by Donald Scott MacKenzie and published by . This book was released on 2000 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quench Sensitivity in 6xxx Series Aluminium Alloys written by Katharina Strobel and published by . This book was released on 2013 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quench sensitivity, the dependence of strength and hardness on the cooling rate after extrusion or solution treatment, limits the applications of extrusions of heat treatable aluminium alloys. Reduced properties in slow cooled samples have long been attributed to the loss of solute on heterogeneous nucleation sites during cooling. While minimum cooling rates to avoid precipitation of Mg-Si-containing phases and reduced properties have been mapped out for a broad range of commercial alloys, little is understood about the physical mechanisms leading to quench sensitivity. In this investigation the difference in hardness evolution between slow cooled and fast quenched samples of various commercial and model Al-Mg-Si alloys has been determined for a broad range of natural and artificial ageing times. This has demonstrated that the artificial ageing response of fast quenched samples differs greatly from the artificial ageing response of slow cooled samples. In contrast to fast cooled samples, where natural ageing has a negative effect, the artificial ageing response of slow cooled samples is less dependent on natural ageing time. As a result, hardness differences between fast and slow cooled samples is large during artificial ageing after short natural ageing times, but small after long natural ageing times, such that quench sensitivity strongly varies. In order to explain this phenomenon, the cooling rate dependent microstructural development has been investigated using hardness measurements, electron microscopy (SEM and TEM), differential scanning calorimetry (DSC) and positron annihilation lifetime spectroscopy (PALS). From TEM investigations and theoretical considerations of the diffusion range it has been determined that solute is only lost from a limited region around the non-hardening precipitates forming during cooling on secondary dispersoids. The increased age hardening rate in fast cooled samples after short natural ageing times is therefore the result of a high vacancy supersaturation rather than a high solute supersaturation compared to slow cooled samples. Non-equilibrium vacancies appear to act as precipitation sites for the precursor of the strengthening [beta]"--Precipitates. In slow cooled samples the formation of [beta]"-precipitates seems to be suppressed. In lean alloys with a low solute content, such as the investigated AA6060, the age hardening response is almost independent of the cooling rate. Small additions of Cu or changes in the Mg:Si-ratio in alloys with a combined Mg+Si-content greater than 1 wt.% have little effect on precipitation of non-hardening phases during cooling, but affect natural and artificial ageing behaviour. The cooling rate after extrusion or solution treatment was also found to affect whether natural ageing has a negative effect or not. In fast cooled samples of Al-Mg-Si alloys with combined Mg+Si-contents greater than 1 wt.% the decrease in ageing kinetics due to the decrease of non-equilibrium vacancies with increasing natural ageing time contributes to the negative effect. In slow cooled samples the initial number of quenched-in vacancies is low, such that ageing kinetics are independent of the natural ageing time.
Download or read book The Influence of Quenching and Aging on Fracture Toughness of the Al Zn Mg Cu Alloy 7449 written by J. Robinson and published by . This book was released on 2014 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: This investigation characterises the fracture toughness of the very high strength Aluminium alloy 7449. This Al-Zn-Mg-Cu alloy is heat treatable and relies on rapid quenching from the solution heat treatment temperature to promote subsequent artificial aging. While the influence of quench paths on strength is well understood and can be predicted using techniques like quench factor analysis, the influence of quench rate on fracture toughness is more challenging. The rate of quenching can influence the fracture toughness through complex precipitation reactions occurring during cooling. The precipitate locations dictate the magnitude of the detrimental effect on the fracture toughness. In this investigation, the fracture toughness of 7449 in two product forms was measured using compact tension specimens cut from forged blocks and rolled plate. These plane strain (KIC) results were also augmented with Charpy impact tests. Various quench conditions were investigated, including water at three different temperatures and poly oxyethylene glycol (PAG) in two concentrations. The influence of standard and novel aging procedures including retrogression and reaging was also determined. The combinations of strength and toughness have been related to the prevailing microstructural condition. Fracture toughness magnitudes were found to vary most significantly with rapidity of cooling from the solution treatment temperature, with the subsequent aging treatments having a much smaller effect.
Download or read book ASM Specialty Handbook written by Joseph R. Davis and published by ASM International. This book was released on 1997-01-01 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials covered include carbon, alloy and stainless steels; alloy cast irons; high-alloy cast steels; superalloys; titanium and titanium alloys; refractory metals and alloys; nickel-chromium and nickel-thoria alloys; structural intermetallics; structural ceramics, cermets, and cemented carbides; and carbon-composites.
Download or read book THE EFFECT OF SOLIDIFICATION RATE AND SOLUTIONIZING QUENCH RATE ON THE MECHANICAL PROPERTIES AND HARDENING RESPONSE OF ALUMINUM ALLOYS written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : A comparative study of five aluminum alloys was performed to characterize the effect of solidification rate and quench rate on casting microstructure and properties. The alloys were cast in the geometry for Jominy End Quench (JEQ) testing, so as to take advantage of the JEQ test's ability to give data on multiple quench rates in a single sample and illustrate the quench sensitivity of an alloy. While the Jominy End Quench test has been used in aluminum alloys, the effects of solidification rates have not been assessed in depth. The work done by other studies has either focused on a single alloy across multiple solidification rates, or on multiple alloys using a single solidification rate. To this end, three molds were created: a sand mold, a semi-permanent mold and a permanent mold, with the intent of casting JEQ bars out of multiple aluminum alloys for direct comparison. The tensile strength, hardness, porosity, and electrical conductivity were assessed, in an attempt to compare the quench sensitivities of the samples. This study will provide a starting point for more in-depth analyses of the alloys, i.e. the kinetics of precipitation strengthening over a range of length scales (cooling rates).
Download or read book Government Reports Annual Index written by and published by . This book was released on 1978 with total page 1610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Alloys Index written by and published by . This book was released on 1990 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1972 with total page 1524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:
