The Study Toughness Ecologicals Metals Materials

2018 ◽  
Vol 69 (10) ◽  
pp. 2737-2739
Author(s):  
Carmen Otilia Rusanescu ◽  
Marin Rusanescu

This aim of this is to determine the manner of realizing tubing pipe, which have to comply with suplimentary requirements concerning the notch impact strength at lower temperature (below - 300C). We realized �73 x 5.51 mm and �89 x 13 mm pipes applying various final heat treatment variants. For each heat treatment variant were determined the mechanical properties and the impact absorbed energy at temperatures between (-60 0C and +15 0C).

2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei

In this paper, the low alloy bainite ductile cast iron has been obtained by a new heat treatment technique of the step austempering in room-temperature machine oil. The effects of element boron, manganese and copper on structure and mechanical properties of the bainite ductile cast Iron in above-mentioned process are investigated. The phenomenon, hardness lag of the alloyed bainite ductile cast Iron, has been discussed. It shows that after the step austempering in room-temperature machine oil, the hardness will increases with the time. It is found that boron and manganese can increase the hardness and reduce the impact strength while copper can increase the impact strength. The results show that reasonable alloyed elements can improve mechanical properties of the bainite ductile cast Iron. Essentially, hardness lag of the alloyed bainite ductile cast Iron is resulted from solute drag-like effect.


10.30544/423 ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 147-162
Author(s):  
Franklin Amaechi Anene ◽  
Nkem Emelike Nwankwo ◽  
Victor Ugochukwu Nwoke

The effect of dopant and heat treatment on the microstructure and mechanical properties of Nickel-aluminum bronze (Cu-10%Al-5%Ni-5%Fe-x%Mo) were extensively investigated. The cast samples were heat treated through different processes, including solutionizing, quenching, and aging; their microstructures were examined using an optical microscope, scanning electron microscopy and energy dispersive spectroscopy analysis and their mechanical properties determined. The microstructure of the as-cast samples consisted of Cu-rich ‘α-phase, ‘κ-phases and small volume fraction of β'-phase while solutionizing transformed the β'-phase to a homogenous β-phase, α, and κ phases. Quenching transformed all β phase to β'-phase, however, aging the alloy precipitated fine dispersive strengthening κ-phases from the quenched microstructure. The results of the mechanical tests showed that the aged samples had improved excellent mechanical properties compared to the as-cast samples. Compared to the base alloy, the tensile strength and hardness of the aged 2% Mo sample increased by 58% and 55%, respectively while the impact strength and elongation decreased by 27% and 22%, respectively. Similarly, the tensile strength and hardness of the aged 3% Mo sample increased by 44% and 49%, respectively, while the impact strength and % elongation decreased by 23.9% and 24.9%, respectively.


2016 ◽  
Vol 16 (2) ◽  
pp. 41-44 ◽  
Author(s):  
A. Jarco ◽  
J. Pezda

Abstract Dispersion hardening, as the main heat treatment of silumins having additions of copper and magnesium, results in considerable increase of tensile strength and hardness, with simultaneous decrease of ductility of the alloy. In the paper is presented an attempt of introduction of heat treatment operation consisting in homogenizing treatment prior operation of the dispersion hardening, to minimize negative effects of the T6 heat treatment on plastic properties of hypereutectoidal AlSi17CuNiMg alloy. Tests of the mechanical properties were performed on a test pieces poured in standardized metal moulds. Parameters of different variants of the heat treatment, i.e. temperature and time of soaking for individual operations were selected basing on the ATD (Thermal Derivation Analysis) diagram and analysis of literature. The homogenizing treatment significantly improves ductility of the alloy, resulting in a threefold increase of the elongation and more than fourfold increase of the impact strength in comparison with initial state of the alloy. Moreover, the hardness and the tensile strength (Rm) of the alloy decrease considerably. On the other hand, combination of the homogenizing and dispersion hardening enables increase of elongation with about 40%, and increase of the impact strength with about 25%, comparing with these values after the T6 treatment, maintaining high hardness and slight increase of the tensile strength, comparing with the alloy after the dispersion hardening.


Author(s):  
Zahid Iqbal Khan ◽  
Zurina Binti Mohamad ◽  
Abdul Razak Bin Rahmat ◽  
Unsia Habib ◽  
Nur Amira Sahirah Binti Abdullah

This work explores a novel blend of recycled polyethylene terephthalate/polyamide 11 (rPET/PA11). The blend of rPET/PA11 was introduced to enhance the mechanical properties of rPET at various ratios. The work’s main advantage was to utilize rPET in thermoplastic form for various applications. Three different ratios, i.e. 10, 20 and 30 wt.% of PA11 blend samples, were prepared using a twin-screw extruder and injection moulding machine. The mechanical properties were examined in terms of tensile, flexural and impact strength. The tensile strength of rPET was improved more than 50%, while the increase in tensile strain was observed 42.5% with the addition of 20 wt.% of PA11. The improved properties of the blend were also confirmed by the flexural strength of the blends. The flexural strength was increased from 27.9 MPa to 48 MPa with the addition of 30 wt.% PA11. The flexural strain of rPET was found to be 1.1%. However, with the addition of 10, 20 and 30 wt.% of PA11, the flexural strain was noticed as 1.7, 2.1, and 3.9% respectively. The impact strength of rPET/PA11 at 20 wt.% PA11 was upsurged from 110.53 to 147.12 J/m. Scanning electron microscopy analysis revealed a dispersed PA11 domain in a continuous rPET matrix morphology of the blends. This work practical implication would lead to utilization of rPET in automobile, packaging, and various industries.


2016 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Zhiyuan Liang ◽  
Wanhua Sha ◽  
Qinxin Zhao ◽  
Chongbin Wang ◽  
Jianyong Wang ◽  
...  

AbstractThe effect of aging heat treatment on the microstructure and mechanical properties of 10Cr20Ni25Mo1.5NbN austenitic steel was investigated in this article. The microstructure was characterized by scanning electron microscopy, energy dispersive spectrometry and transmission electron microscopy. Results show that the microstructure of 10Cr20Ni25Mo1.5NbN austenitic is composed of austenite. This steel was strengthened by precipitates of secondary phases that were mainly M23C6 carbides and NbCrN nitrides. As aging treatment time increased, the tensile strength first rose (0–3,000 h) and then fell (3,000–5,000 h) due to the decrease of high density of dislocations. The impact absorbed energy decreased sharply, causing the sulfides to precipitate at the grain boundary. Therefore, the content of sulfur should be strictly controlled in the steelmaking process.


2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.


2003 ◽  
Vol 19 (2) ◽  
pp. 61-76 ◽  
Author(s):  
Tasnim Kallel ◽  
Valérie Massardier-Nageotte ◽  
Mohamed Jaziri ◽  
Jean-François Gérard ◽  
Boubaker Elleuch

PE/PS blends have been extensively studied with the objective of improving their recycling. The objective of the present study was to investigate the effect of potential pollutants on properties of high density polyethylene (HDPE)/polystyrene (PS) plastic blends. The pollutants selected were a polar molecule of low molar mass, i.e. ethylene glycol, and an oil for engine which can be considered as less polar higher molar mass molecules. Such study can be considered for the recycling of polymer wastes from automotive applications. The compatibilizer used for PE/PS blends was a non-grafted Styrene-Ethylene Butene-Styrene copolymer (SEBS). Rheological properties, morphology and mechanical properties were analyzed. Study of the morphologies and of the mechanical properties shows that a small polar molecule such as ethylene glycol can form a third phase whereas an oil can improve compatibilization (lower diameter of the dispersed phase, better adhesion). Morphologies are in good agreement with mechanical behavior. For PE/PS blends, the lower adhesion due to the presence of ethylene glycol induced a decrease of the viscosity and absorbed energy. On the opposite, the presence of oil decreases the diameter of the dispersed phase, which leads to a significant improvement of the impact properties.


2017 ◽  
Vol 17 (3) ◽  
pp. 55-58
Author(s):  
A. Jarco

Abstract The paper presents research on the effects of soft annealing parameters on a change of the impact strength KC and Brinell hardness (HB) of the EN AC-AlSi11 alloy. The research has been performed according to the trivalent testing plan for two input parameters – temperature in the range between 280°C and 370°C and time in the range between 2 and 8 hours. The application of such heat treatment improves the plasticity of the investigated alloy. The improvement of the impact strength KC by 71% and the decrease of the hardness HB by 20% was achieved for the soft annealing treatment conducted at a temperature 370°C for 8 hours, compared to the alloy without the heat treatment. A change of the form of eutectic silicon precipitations which underwent refinement, coagulation and partial rounding, had a direct effect on the hardness HB and impact strength KC. The results obtained were used to prepare space plots enabling the temperature and time for soft annealing treatment to be selected with reference to the obtained impact strength KC and hardness HB of the alloy with the heat treatment.


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