Effect of different heat-treatment routes on the impact properties of an additively manufactured AlSi10Mg alloy

2021 ◽  
Vol 802 ◽  
pp. 140671
Author(s):  
Maverick Giovagnoli ◽  
Marialaura Tocci ◽  
Annalisa Fortini ◽  
Mattia Merlin ◽  
Matteo Ferroni ◽  
...  
2013 ◽  
Vol 834-836 ◽  
pp. 816-819 ◽  
Author(s):  
Li Jun Tan ◽  
Jun Qiao Wang ◽  
Qing Qun Wang ◽  
Xin Long Chen ◽  
Si Zhu Zhou

The tensile and impact properties of SAE4320 and SAE8620 alloys were investigated. Various heat treatments were applied to these two alloys, including different pre-heat treatment. The results shown that after Carburizing and Quenching, both SAE4320 and SAE8620 alloys were highly sensitively to V-notches for their impact samples. In any case, SAE4320 alloy revealed higher tensile strength, better impact toughness and deformation property. Previous work shown that after Carburizing and Quenching, the impact toughness of SAE8620 alloy was too low, the products made of it was very dangerous. Based on the results, a new advanced product was made of SAE4320 alloy instead of SAE8620 alloy. And the new product exhibited good properties. The impact value of the new product far exceeded the older products.


2012 ◽  
Vol 1381 ◽  
Author(s):  
M. Merlin ◽  
R. Vazquez-Aguilar ◽  
C. Soffritti ◽  
A. Reyes-Valdes

ABSTRACTIn this study the influence of heat input (HI) and heat treatment on submerged arc welded duplex SAF 2205 steel joints has been evaluated. In particular, multi-pass welding operations have been performed on 18 mm thick plates using four different heat inputs; a post-weld solubilizing heat treatment has been carried out in order to reduce the microstructural effects on the structure of the heat affected zone (HAZ). Instrumented impact strength tests have been performed on Charpy samples machined from the welded joints; the total absorbed energy and the two complementary contributions of initiation and propagation energies have been evaluated and correlated to the percentages of ferrite and austenite. The microstructures and the fracture profiles have been observed using an optical microscope (OM) and quantitatively analyzed by means of an image analyzer. A scanning electron microscope (SEM) equipped by energy dispersive X-ray spectroscopy (EDS) has been used to study the fractured surfaces. Hardness profiles have been performed across the joints in order to verify the hardness variations. A total absence of secondary phases has been found on the joints due to the performing of a suitable solubilizing heat treatment after the welding process. The results have shown that the impact properties of the samples have been mostly affected by the different heat inputs; in some cases a partial welding penetration has been found.


Author(s):  
Hee Kyung Kwon ◽  
Byoung Koo Kim ◽  
Kuk Cheol Kim ◽  
Keun Ho Song ◽  
Jeong Tae Kim

Nuclear power plants have been operated for fifty years. Currently the managements of spent fuel are on progress vigorously. Casks for transportation and/or storage of spent nuclear fuel are usually made of SA350 low alloy steels. The wall thickness of the casks are greater than 300mm. But because leakage of nuclear fuel or radioactive material from unexpected brittle fracture is not acceptable, Nil-ductility transition temperatures of colder than −150°F are needed. The effects of chemical composition and heat treatment on low temperature impact properties of SA350 are investigated in this study. The microstructure of SA350 steel is composed of ferrite and pearlite. The variations of microstructure, low temperature impact properties and strength at room temperature with carbon, vanadium and manganese content are analyzed. To improve the low temperature impact properties, heat treatment at an temperature between quenching and tempering temperature is introduced. With the optimum combination of alloying elements and heat treatment, the impact properties can be improved down to the level of nil-ductility transition temperature −150°F.


1975 ◽  
Vol 97 (2) ◽  
pp. 408-416 ◽  
Author(s):  
R. J. Jesseman ◽  
R. C. Smith

The effects of straining, straining + aging, and straining + aging + stress-relieving on tensile and Charpy V-notch impact properties were determined for several candidate arctic pipe and fitting steels. Possible compositional and processing means to maintain high as-rolled energy levels in strained + aged pipe are discussed. Heat treatment of 787 and Mn-Mo-Cb, as would be necessary in fittings, increased toughness to the level that degradation due to straining + aging was readily accommodated even at −80°F (−62°C) test temperatures. For fittings designed to −20°F (−29°C) or higher service temperatures, Armco VNT-QT with restricted carbon content and sulfide shape control provided adequate toughness in the strained + aged condition. After stress-relieving, the impact properties improved enough to allow use of this grade at −80°F (−62°C).


Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.


Author(s):  
Fatemeh Alizadeh ◽  
Navid Kharghani ◽  
Carlos Guedes Soares

Glass/Vinylester composite laminates are comprehensively characterised to assess its impact response behaviour under moisture exposure in marine structures. An instrumented drop weight impact machine is utilised to determine the impact responses of dry and immersed specimens in normal, salted and sea water. The specimens, which had three different thicknesses, were subjected to water exposure for a very long period of over 20 months before tested in a low-velocity impact experiment. Water uptake was measured primarily to study the degradation profiles of GRP laminates after being permeated by water. Matrix dissolution and interfacial damage observed on the laminates after prolonged moisture exposure while the absorption behaviour was found typically non-Fickian. The weight of the composite plates firstly increased because of water diffusion up to month 15 and then decreased due to matrix degradation. The specimens with 3, 6 and 9 mm thickness exhibited maximum water absorption corresponding to 2.6%, 0.7% and 0.5% weight gain, respectively. In general, the results indicated that water uptake and impact properties were affected by thickness and less by water type. Impact properties of prolonged immersed specimens reduced remarkably, and intense failure modes detected almost in all cases. The least sensitive to impact damage were wet specimens with 9 mm thickness as they indicated similar maximum load and absorbed energy for different impact energies.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 321
Author(s):  
Camila Mella ◽  
Michelle Quilaqueo ◽  
Rommy N. Zúñiga ◽  
Elizabeth Troncoso

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.


Sign in / Sign up

Export Citation Format

Share Document