scholarly journals Effect of rapid Solidification on mechanical properties of free machining lead free aluminum alloys for improved machinability

2017 ◽  
pp. 5155-5166
Author(s):  
Nermin Ali Abdelhakim ◽  
Rizk Mostafa Shalaby ◽  
Mustafa Kamal
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Stress ◽  
Thermal Properties ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Critical Shear Stress ◽  
Lead Free ◽  
Test Machine ◽  
Melt Spun

There have been very few reports describing the free machining lead free aluminum alloys containing minimal amounts of tin and indium melt spun process. Our paper describes the effect of fundamental factors on the machinability of free machining lead free aluminum alloys rapidly solidified from melt. Structural and thermal properties have been investigated by x-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques. Tensile test machine used in studies the mechanical properties such as ultimate tensile strength, elastic constants, yield strength and critical shear stress for Al-Zn-Sn-In alloys. It is noticed that mechanical and thermal properties attributed to fine grained structure, reduced levels of segregation and presence of new intermetallic compounds (IMC) such as AlZn and SnZn due to high casting rate by rapid solidification processes. The determination of mechanical properties was suggested to be attributed to the gradual increase of α-Al crystals. We evaluated the tensile properties using tensile test machine of the melt-spun ribbons at varied stress-strain rates to determine the underlying deformation mechanisms .Critical shear stress (CSS) was also calculated .It was found that it is equal to 9.29 GPa for annealed ribbons at 262 0C for 9 hrs. The results showed that several combination of tensile strength ,yield strength ,elastic moduli can be generated from Al- 0.1wt% Zn-1.5 wt% Sn- 1.63 wt% In alloys before and after heat treatment at (262 0C for 3,6,9 hrs) to meet the needs of free machining aluminum alloy applications.                                                                        

Nickel effects on the structural and some physical properties of the eutectic Sn-Ag lead-free solder alloy

2019 ◽  
Vol 31 (1) ◽  
pp. 40-51 ◽  
Author(s):  
Mohammed S. Gumaan ◽  
Rizk Mostafa Shalaby ◽  
Mustafa Kamal Mohammed Yousef ◽  
Esmail A.M. Ali ◽  
E. E. Abdel-Hady
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Stress ◽  
Thermal Diffusivity ◽  
Strain Rate ◽  
High Strain ◽  
Critical Shear Stress ◽  
Content Type ◽  
Melt Spun ◽  
Ni Additions

PurposeThis study aims to investigate the structural, mechanical, thermal and electrical properties of tin–silver–nickel (Sn-Ag-Ni) melt-spun solder alloys. So, it aims to improve the mechanical properties of the eutectic tin–silver (Sn-Ag) such as tensile strength, plasticity and creep resistance by adding different concentrations of Ni content.Design/methodology/approachTernary melt-spun Sn-Ag-Ni alloys were investigated using x-ray diffractions, scanning electron microscope, dynamic resonance technique (DRT), Instron machine, Vickers hardness tester and differential scanning calorimetry.FindingsThe results revealed that the Ni additions 0.1, 0.3, 0.5, 0.7, 1, 3 and 5 Wt.% to the eutectic Sn-Ag melt-spun solder were added. The “0.3wt.%” of Ni was significantly improved its mechanical properties to efficiently serve under high strain rate applications. Moreover, the uniform distribution of Ag3Sn intermetallic compound with “0.3wt.%” of Ni offered the potential benefits, such as high strength, good plasticity consequently and good mechanical performance through a lack of dislocations and microvoids. The tensile results showed improvement in 17.63 per cent tensile strength (26 MPa), 21 per cent toughness (1001 J/m3), 22.83 per cent critical shear stress (25.074 MPa) and 11 per cent thermal diffusivity (2.065 × 10−7m2/s) when compared with the tensile strength (21.416 MPa), toughness (790 J/m3), critical shear stress (19.348 MPa) and thermal diffusivity (1.487 × 10−7m2/s) of the eutectic Sn-Ag. Slight increments have been shown for the melting temperature of Sn96.2-Ag3.5-Ni0.3(222.62°C) and electrical resistivity to (1.612 × 10−7Ω.m). It can be said that the eutectic Sn-Ag solder alloy has been mechanically improved with “0.3wt.%” of Ni to become a suitable alloy for high strain rate applications. The dislocation movement deformation mechanism (n= 4.5) without Ni additions changed to grain boundary sliding deformation mechanism (n= 3.5) with Ni additions. On the other hand, the elastic modulus, creep rate and strain rate sensitivity with “0.3wt.%” of Ni have been decreased. The optimum Ni-doped concentration is “0.7wt.%” of Ni in terms of refined microstructure, electrical resistivity, Young’s Modulus, bulk modulus, shear modulus, thermal diffusivity, maximum shear stress, tensile strength and average creep rate.Originality/valueThis study provides nickel effects on the structural of the eutectic Sn-Ag rapidly solidified by melt-spinning technique. In this paper, the authors have compared the elastic modulus of the melt-spun compositions which has been resulted from the tensile strength tester with these results from the DRT for the first time to best of the authors’ knowledge. This paper presents new improvements in mechanical and electrical performance.

scholarly journals Effect of Mn on Microstructure and Mechanical Properties of Al-4Ni Alloy

JOM ◽  
2021 ◽  
Author(s):  
Jiao Fang ◽  
Xixi Dong ◽  
Shouxun Ji
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Elevated Temperatures ◽  
Strength Loss ◽  
Good Thermal Stability ◽  
Microstructure And Mechanical Properties

AbstractThe application of aluminum alloys at elevated temperatures has been attractive for decades, and Al-Ni-based alloys have recently been recognized as potential candidates. The effect of Mn on Al-4Ni alloy has been investigated in this work. Addition of Mn transformed the eutectics from Al3Ni/α-Al to Al9(Ni,Mn)2/α-Al phases. Mn also improved the tensile strength at both 25°C and 250°C. The yield strength at 25°C increased from 48 MPa to 92 MPa with 1.87% Mn and then to 117 MPa with 3.77% Mn. At 250°C, the yield strength increased from 35 MPa to 82 MPa with 1.87% Mn and then to 101 MPa with 3.77% Mn. The alloys with Mn also showed less strength loss than Al-4Ni alloy at 250°C. The eutectic Al9(Ni,Mn)2 phase showed good thermal stability. No coarsening was observed after 2000 h at 250°C.

Comparative Studies of Nanostructured Aluminum Alloys by Destructive and Nondestructive Testing

2015 ◽  
Vol 1119 ◽  
pp. 9-13 ◽  
Author(s):  
Natalia Lvova ◽  
Ivan Evdokimov ◽  
Sergey Perfilov
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Aluminum Alloys ◽  
Nondestructive Testing ◽  
Yield Strength ◽  
Comparative Study ◽  
Comparative Studies ◽  
Carbon Nanostructures ◽  
Strength Testing

This work provides a comparative study of the mechanical properties of composite materials based on aluminum reinforced with carbon nanostructures. The study involved the tensile strength testing, as well as sclerometry and indentation in the submicron range. We determined the correlation of the values obtained for yield strength and hardness, and the tensile strength and morphology of the residual scratches.

Microstructure Evolution and Property of Austenitic Stainless Steel after ECAP

2012 ◽  
Vol 268-270 ◽  
pp. 291-296
Author(s):  
Li Min Wang ◽  
Zhi Hua Gong ◽  
Gang Yang ◽  
Zheng Dong Liu ◽  
Han Sheng Bao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Shear Stress ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Microstructure Evolution ◽  
Ultrafine Grain ◽  
Angular Pressing

Ultrafine-grain or even nano-grain microstructure can be made by equal channel angular pressing (ECAP), mainly resulting from shear strain. The authors experimentally investigated 00Cr18Ni12 austenitic stainless steel and its mechanical properties during and after ECAP. The results showed that because of larger shear stress, many slipping bands occured inside grains, with the increase of pressing pass, the slipping bands may interact with each other to separate slipping bands into sub-grains, finally, the sub-grains transformed into new grains with large angular boundaries. The grain size was about 200nm after the 7th pass. After the 1st and 2nd pass, the tensile strength was higher 93% and 144% than that without ECAP, the yield strength was 5.3 and 6.6 times of that without ECAP respectively.

scholarly journals Melt- vs. Non-Melt Blending of Complexly Processable Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 404
Author(s):  
Nur Sharmila Sharip ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Yoshito Andou ◽  
Yuki Shirosaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Yield Strength ◽  
Young’S Modulus ◽  
High Molecular Weight ◽  
Melt Processing ◽  
Cellulose Nanofiber ◽  
Melt Blending ◽  
Ultra High Molecular Weight

The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.

scholarly journals Enhanced lattice distortion, yield strength, critical resolved shear stress, and improving mechanical properties of transition-metals doped CrCoNi medium entropy alloy

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23719-23724
Author(s):  
Md. Lokman Ali
Keyword(s):  
Mechanical Properties ◽  
Shear Stress ◽  
Transition Metals ◽  
Yield Strength ◽  
Lattice Distortion ◽  
Critical Resolved Shear Stress

The effect of transition-metals (TM) addition on the mechanical properties of CrCoNi medium entropy alloys (MEAs) was investigated.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

Quantitative Analysis of Pre-Strain Effect on Mechanical Properties of the Austenitic Stainless Steel

2014 ◽  
Author(s):  
Zhiwei Chen ◽  
Caifu Qian ◽  
Guoyi Yang ◽  
Xiang Li
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Tensile Testing ◽  
Control Mode ◽  
Strain Effect ◽  
Strain Control

The test of austenitic stainless steel specimens with strain control mode of pre-strain was carried out. The range of pre-strain is 4%, 5%, 6%, 7%, 8%, 9% and 10% on austenitic stainless steel specimens, then tensile testing of these samples was done and their mechanical properties after pre-strain were gotten. The results show that the pre-strain has little effect on tensile strength, and enhances the yield strength more obviously. According to the experimental data, we get a relational expression of S30408 between the value of yield strength and pre-strain. We can obtain several expressions about different kinds of austenitic stainless steel by this way. It is convenient for designers to get the yield strength of austenitic stainless steel after pre-strain by the value of pre-strain and the above expression.

Strength of Commercial Aluminum Alloys after Equal Channel Angular Pressing and Post-ECAP Processing

2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloys ◽  
Ultimate Tensile Strength ◽  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Solution Treatment ◽  
Ecap Processing ◽  
Angular Pressing

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.

Mechanical And Superconducting Properties Of Cu-Nb3Sn In Situ Produced Composite Wires

1981 ◽  
Vol 12 ◽  
Author(s):  
A. Kolb-Telieps ◽  
B.L. Mordike ◽  
M. Mrowiec
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Wide Temperature Range ◽  
Volume Fraction ◽  
Superconducting Properties ◽  
Temperature Range ◽  
Composite Wires ◽  
Strength And Ductility

ABSTRACTCu-Nb composite wires were produced from powder, electrolytically coated with tin and annealed to convert the Nb fibres to Nb 3Sn. The content was varied between 10 wt % and 40 wt %. The superconducting properties of the wires were determined. The mechanical properties, tensile strength, yield strength and ductility were measured as a function of volume fraction and deformation over a wide temperature range. The results are compared with those for wires produced by different techniques.

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