Tensile strength improvement of martensitic ODS steels with Zr and Hf additions

2022 ◽  
Vol 829 ◽  
pp. 142071
Author(s):  
Xiaosheng Zhou ◽  
Guodong Li ◽  
Xingquan Shen ◽  
Yongchang Liu
2017 ◽  
Vol 25 (3) ◽  
pp. 161-170
Author(s):  
Henny Lydiasari ◽  
Ari Yusman Manalu ◽  
Rahmi Karolina

The potency of oil palm empty fruit bunches (OPEFB) fibers as one of the by-products of processing oil palm is increasing significantly so that proper management is needed in reducing environmental impact. One of the utilization of OPEFB fibers is as a substitution material in construction which usually the material is derived from non-renewable mining materials so that the number is increasingly limited. Therefore, it is necessary to study to know the performance of OPEFB fiber in making construction products especially concrete. In this case, the experiment was conducted using experimental method with variation of fiber addition by 0%, 10%, 15%, 20%, 25%, and 30%. Each specimen was tested by weight, slump value, compressive strength, tensile strength, elasticity and crack length. As the results, the variation of fibers addition by 10%, decrease of slump value is 7%, concrete weight is 3% and crack length is 8% while increase of the compressive strength is 2.7% and the modulus of elasticity is 33.3% but its tensile strength decreased insignificantly by 0.05% . Furthermore, the addition of fibers above 10% to 30% decreased compressive strength is still below 10% and tensile strength below 2% while the weight of concrete, slump value and crack length decreased. Therefore, the addition of 10% can replace the performance of concrete without fiber but the addition of above 10% can still be used on non-structural concrete.


2021 ◽  
Vol 21 (9) ◽  
pp. 4897-4901
Author(s):  
Hyo-Sang Yoo ◽  
Yong-Ho Kim ◽  
Hyeon-Taek Son

In this study, changes in the microstructure, mechanical properties, and electrical conductivity of cast and extruded Al–Zn–Cu–Mg based alloys with the addition of Li (0, 0.5 and 1.0 wt.%) were investigated. The Al–Zn–Cu–Mg–xLi alloys were cast and homogenized at 570 °C for 4 hours. The billets were hot extruded into rod that were 12 mm in diameter with a reduction ratio of 38:1 at 550 °C. As the amount of Li added increased from 0 to 1.0 wt.%, the average grain size of the extruded Al alloy increased from 259.2 to 383.0 µm, and the high-angle grain boundaries (HGBs) fraction decreased from 64.0 to 52.1%. As the Li content increased from 0 to 1.0 wt.%, the elongation was not significantly different from 27.8 to 27.4% and the ultimate tensile strength (UTS) was improved from 146.7 to 160.6 MPa. As Li was added, spherical particles bonded to each other, forming an irregular particles. It is thought that these irregular particles contribute to the strength improvement.


An attempt has been made in this paper to study the effect on the mechanical properties of the concrete and hollow concrete block when different types of fibres were added to the mix. The two different types of fibres added include Steel fibres with hooked end and of length 60mm at five different fibre ratios of 2.5%, 2.75%, 3.0%, 3.25% and 3.5% and Nylon fibres having a length of 18mm at the content of 0.5%, 0.75%, 1.0%, 1.25% and 1.50%. The concept of fibre hybridization was also analyzed and the effect was studied by preparing concrete mix with various percentage combinations of steel and nylon fibres at a total fibre ratio of 3% by weight of cement. The investigation focused on finding the optimum values of fibres to be added and also carried out the compressive strength and tensile strength of concrete with and without fibres. The compressive strength of hollow concrete blocks made with and without fibres was also analyzed. The samples of concrete and hollow concrete blocks were cast and immersed in water for a curing period of 28 days. The results on strength of fibre added concrete and hollow concrete block obtained was compared with the control mix result and the study concludes that the steel fibre and nylon fibre added concrete and hollow concrete block showed an improvement in the mechanical properties for each fibre ratio considered. Out of the various combinations of steel and nylon fibre tried, the best compressive strength improvement was exhibited by the concrete mix with 3% of the steel fibre without any addition of nylon fibres while the best tensile strength improvement was shown by the concrete mix with 2.25% of steel fibre and 0.75% of nylon fibre.


2012 ◽  
Vol 488-489 ◽  
pp. 19-21
Author(s):  
Chao Jue Yi ◽  
Peng Cheng Zhai ◽  
Li Zhou Dong ◽  
Qi Hao Fu

By using cryogenic treatment on 7A04 aluminum alloy tested with micrographic analysis and mechanical properties test, we studied the impact on mechanical properties of 7A04 aluminum alloy The results showed that the strength of 7A04 aluminum alloy could be highly increased and the grain size would be reduced in the process through being treated in 480°C/80min + aging in 120°C/4h + cryogenic treatment + aging at 120°C/16h.7A04 aluminum alloy are more fully recrystallized to grain refinement and the tensile strength of it can be increased to 720Mpa after the treatment.


Author(s):  
Muhammad Rizwan ◽  
Shaheer Khaleequzzaman ◽  
Uzair Khaleeq uz Zaman ◽  
Syed Aqib Fida ◽  
Amjed Shahzad ◽  
...  

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