Mechanical properties of nickel beryllides

1989 ◽  
Vol 4 (6) ◽  
pp. 1347-1353 ◽  
Author(s):  
T. G. Nieh ◽  
J. Wadsworth ◽  
C. T. Liu
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Elastic Properties ◽  
Room Temperature ◽  
Vickers Microhardness ◽  
Interstitial Oxygen ◽  
Equiatomic Composition ◽  
Room Temperature Ductility ◽  
Hardness Increase ◽  
Microhardness Tester

The elastic properties of nickel beryllide have been evaluated from room temperature to 1000 °C. The room temperature modulus is measured to be 186 GPa, which is relatively low by comparison with other B2 aluminides such as NiAl and CoAl. Hardness measurements were carried out on specimens that had compositions over the range from 49 to 54 at. % Be, using both a Vickers microhardness tester and a nanoindentor. It was found that the hardness of NiBe exhibits a minimum at the equiatomic composition. This behavior is similar to that of aluminides of the same crystal structure, e.g., NiAl and CoAl. The effect of interstitial oxygen on the hardness of NiBe has also been studied and the results show that the presence of oxygen in NiBe can cause a significant increase in hardness. It is demonstrated that the hardness increase for the off-stoichiometric compositions is primarily caused by interstitial oxygen and can only be attributed partially to anti-site defects generated in off-stoichiometric compositions. Nickel beryllides appear to have some intrinsic room temperature ductility, as evidenced by the absence of cracking near hardness indentations.

Influence of Stoichiometry on the Strength of Nickel Beryllide

1988 ◽  
Vol 133 ◽  
Author(s):  
T. G. Nieh ◽  
J. Wadsworth ◽  
C. T. Liu
Keyword(s):  
Room Temperature ◽  
Crystallographic Structure ◽  
Interstitial Oxygen ◽  
Equiatomic Composition ◽  
Defect Structures ◽  
Room Temperature Ductility ◽  
Hardness Increase

ABSTRACTIt is demonstrated that the hardness of NiBe is dependant upon its stoichiometry; a minimum hardness is observed at the equiatomic composition. This behavior is similar to intermetallics that have the same crystallographic structure, e.g., NiAI and CoAl. The hardness increase for the off-stoichiometric compositions is a result of defect and anti-site defect structures, but may also, in part, be caused by interstitial oxygen. Nickel beryllides appear to have some intrinsic room temperature ductility, as evidenced by the absence of cracking near hardness indentations.

Effect of Cerium and Lanthanum Addition on Mechanical Properties of Bismuth Titanate Ceramics

2009 ◽  
Vol 409 ◽  
pp. 330-333
Author(s):  
Nina Pavlovic ◽  
Dragan Rajnovic ◽  
L. Sidjanin ◽  
Vladimir V. Srdic
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Bismuth Titanate ◽  
Vickers Microhardness ◽  
Grain Morphology ◽  
Sintering Behaviour ◽  
Titanate Ceramics ◽  
Hardness Values ◽  
Microhardness Tester

Cerium- and lanthanum- substituted bismuth titanate (Bi4-xAxTi3O12; where A=La or Ce, and x=0, 0.5 and 1) ceramics were prepared from nanopowders synthesized by coprecipitation method. The as-synthesized powders were calcined, uniaxially pressed and finally sintered at 1050°C. It was shown that sintering behaviour, phase composition and grain morphology of the obtained ceramics were influenced by the presence of lanthanum and especially cerium ions in the titanate structure. Mechanical properties (hardness and fracture toughness) were measured at room temperature on polished sample surfaces using a Vickers microhardness tester. The hardness values for of bismuth titanate based ceramics were in the range for some other important perovskite titanate, whereas their fracture toughness was somewhat higher.

scholarly journals A review of recent developments in Fe3Al-based alloys

1991 ◽  
Vol 6 (8) ◽  
pp. 1779-1805 ◽  
Author(s):  
C.G. McKamey ◽  
J.H. DeVan ◽  
P.F. Tortorelli ◽  
V.K. Sikka
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Iron Aluminides ◽  
Alloy Development ◽  
Sharp Drop ◽  
Environmental Embrittlement ◽  
Room Temperature Ductility ◽  
Structural Applications ◽  
Recent Developments ◽  
Mechanical Properties And Corrosion

Fe3Al-based iron aluminides have been of interest for many years because of their excellent oxidation and sulfidation resistance. However, limited room temperature ductility (<5%) and a sharp drop in strength above 600 °C have limited their consideration for use as structural materials. Recent improvements in tensile properties, especially improvements in ductility produced through control of composition and microstructure, and advances in the understanding of environmental embrittlement in intermetallics, including iron aluminides, have resulted in renewed interest in this system for structural applications. The purpose of this paper is to summarize recent developments concerning Fe3Al-based aluminides, including alloy development efforts and environmental embrittlement studies. This report will concentrate on literature published since about 1980, and will review studies of fabrication, mechanical properties, and corrosion resistance that have been conducted since that time.

Atomic simulation of mechanical properties of irradiated iron

2019 ◽  
Vol 31 (02) ◽  
pp. 2050027
Author(s):  
Lei Ma ◽  
Changsheng Li ◽  
Ailong Zhang ◽  
Wangyu Hu
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Tensile Test ◽  
Room Temperature ◽  
Stacking Faults ◽  
Dynamics Simulation ◽  
Stress And Strain ◽  
Micro Structure ◽  
Atomic Simulation

The mechanical properties of irradiated iron are studied by molecular dynamics simulation. The initial models are irradiated with the energy of primary knocked-on atoms (PKA) of 10[Formula: see text]keV at 100, 300, 500 and 600 K, and then all the irradiated models are subjected to tensile test. The results reveal that the mechanical properties of irradiated iron are changed compared with un-irradiated iron, the yield stress and strain decrease after irradiation, and the irradiation causes the hardening of micro-structure at low temperature and high temperature, but it results in the softening of structure at room temperature. The plastic reduces for irradiated iron under tensile test, more stacking faults are formed in the crystal structure as the temperature increases.

Effect of Aging Process on Microstructure and Room Temperature Ductility of TB6 Titanium Alloy

2014 ◽  
Vol 1061-1062 ◽  
pp. 567-570
Author(s):  
Cui Ye ◽  
Fei Zhao ◽  
Fang Zhou ◽  
Ni Li ◽  
Jun Shuai Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Aging Time ◽  
Aging Temperature ◽  
Aging Process ◽  
Room Temperature ◽  
Room Temperature Ductility ◽  
Tb6 Titanium Alloy

Microstructure and room temperature ductility of the TB6 titanium alloy was investigated by varying the aging temperature and the aging time.The results show that, the alloy’s contraction of area increases while the tensile strength firstly increases and then decreases by raising their aging temperature. In general, the ductility of the samples increases and the strength decreases with the increasing aging time. The optimum mechanical properties are obtained by aging at 650 °C for 2 h.

Effects of Annealing on Microstructure and Mechanical Properties of Bulk Nanocrystalline Fe3Al Based Alloy with 10 Wt. % Mn Prepared by Aluminothermic Reaction

2011 ◽  
Vol 236-238 ◽  
pp. 1939-1944
Author(s):  
Pei Qing La ◽  
Xin Guo ◽  
Yang Yang ◽  
Chun Jie Cheng ◽  
Xue Feng Lu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Grain Size ◽  
Room Temperature ◽  
Annealed Alloy ◽  
Creep Properties ◽  
Aluminothermic Reaction ◽  
Microstructure And Mechanical Properties ◽  
Bulk Nanocrystalline ◽  
Hot Rolled

Microstructure and mechanical properties of bulk nanocrystalline Fe3Al based alloy with 10 wt. % Mn prepared by aluminothermic reaction after annealing at 600, 800 and 1000°C for 8 h were investigated in order to gain insights in effects of annealing. Crystal structure of the alloy did not change and a fiber phase with enriched Mn appeared in the annealed alloy. Grain size of the alloy changed a little after annealing at 600°C but increased a lot after annealing at 800 and 1000°C. The annealed alloy had plasticity in compression at room temperature and the alloy annealed at 1000°C had yield strength of 782 MPa. The alloy without annealing has creep properties in compression at 800 and 1000°C and can be easily hot rolled to strip and sheet.

Phase Stability, Microstructure and Mechanical Properties in the Multi-Phse Alloys Based on the L12-Ni3(Al,Be)

1994 ◽  
Vol 364 ◽  
Author(s):  
Takahiro Matsuo ◽  
Hideki Hosoda ◽  
Seiji Miura ◽  
Yoshinao Mishima
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Room Temperature ◽  
Vertical Section ◽  
Intermetallic Alloys ◽  
Primary Solidification Phase ◽  
Four Point Bending ◽  
Room Temperature Ductility ◽  
Three Phase ◽  
Multi Phase

AbstractIntermetallic alloys based on the Ll2 Ni3(Al,Be) phase in the ternary Ni-Al-Bc system are prepared so that the alloys are multi-phase with the B2 intermetallic compound NiBe and a Ni primary solid solution denoted as (Ni). Such three-phase alloys, Ni-16 to 20 at%Al-10 at%Be, exhibit good room temperature ductility as measured by four-point bending. In order to examine the phase stabilities and relations among constituent phases, a vertical section of the ternary system is constructed at a constant 10 at%Bc mainly by differential thermal analysis. It is found that improvement in room temperature ductility can be achieved by the formation of a fine mixture of constituent phases during invariant reactions during solidification, which is further enhanced by the co-existence of the Ll2 phase formed as the primary solidification phase.

Shape Memory Behavior and Mechanical Properties of NiMn and Ni(Mn,X) Alloys

1991 ◽  
Vol 246 ◽  
Author(s):  
W.S. Yang ◽  
D.E. Mikkola
Keyword(s):  
Mechanical Properties ◽  
Transition Temperature ◽  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Transformation Temperatures ◽  
Room Temperature Ductility ◽  
Substitutional Solute ◽  
Ternary Element ◽  
High Transition

AbstractPotential high transition temperature shape memory alloys based on NiMn have been studied with emphasis on the shape recovery, transformation temperatures and mechanical properties. Binary NiMn, which has been reported to be brittle, has a low shape recovery, but this can be increased with Al or Ti additions. Also, the transformation temperature can be changed and the room temperature ductility improved by ternary element additions. The various substitutional solute characteristics affecting the shape recovery, the transformation temperatures, and the ductility have been examined.

Microstructure Evolution and Mechanical Properties of Extruded Mg-Al-Zn-Sn Alloy Sheets

2017 ◽  
Vol 898 ◽  
pp. 300-304
Author(s):  
Qing Shan Yang ◽  
Wen Jun Liu ◽  
Zu Jian Yu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Extrusion Process ◽  
Extrusion Ratio ◽  
Mg Alloy ◽  
Casting Method ◽  
Mechanical Responses ◽  
Room Temperature Ductility ◽  
Differential Speed ◽  
Scanning Electron

The microstructure and mechanical responses of the AZ31 with the addition of 1.8% Sn alloys have been studied and compared. Mg alloy sheets were prepared with metal model casting method and subsequent processes by conventional extrusion (CE) and differential speed extrusion (DSE). Mg alloys were hot extruded at 400oC with the extrusion ratio of 101:1. The microstructure of Mg alloy sheets was examined by optical microscopy (OM) and scanning electron microscope (SEM). The results indicated that the grains were dynamically recrystallized after the extrusion process. Moreover, DSE process dramatically enhanced the room temperature ductility of the extruded sheets. It was also presented that the Mg alloy processed by DSE exhibite a classical dimple structure as a result of slip accumulation and ductile tear.

Effect of Silicon Nitride (Si3N4) Addition on the Mechanical and Tribological Performance of Al-Fe-Si Alloy (AA8011)

2020 ◽  
Vol 982 ◽  
pp. 34-38
Author(s):  
Juwon Fayomi ◽  
A.P.I. Popoola ◽  
O.M. Popoola ◽  
O.P. Oladijo
Keyword(s):  
Mechanical Properties ◽  
Vickers Microhardness ◽  
Testing Machine ◽  
Casting Process ◽  
Stir Casting ◽  
Tribological Performance ◽  
Dry Sliding ◽  
Alloy Matrix ◽  
Universal Testing ◽  
Microhardness Tester

This research examines the effect of ceramic particulate of Si3N4 on the hardness, tensile, corrosion, and microstructure of reinforced AA8011 composites. The composites were developed by two steps stir casting process where both the particulates and the alloy matrix were preheated and melted respectively before mixing. 0%, 5%, 10%, 15%, and 20% Si3N4 particulates compositions were varied to fabricate the composites. Vickers microhardness tester was employed to study the hardness, the universal testing machine was used to analyze the ultimate tensile strength, the tribological performances of the developed composites AA8011-Si3N4 were analyzed under dry sliding condition using Universal Tribometer. The results of the experiment clearly revealed the improvement in the mechanical properties of the composites compared to the primary Al-Fe-Si alloy with excellent strength mechanism recorded at 20% reinforcement. Composites with 20% Si3N4 was found to have a better wear resistance hence, lowest wear rate.

Sign in / Sign up

Export Citation Format

Share Document