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.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

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.

Mechanical Properties of Thermal Barrier Coatings at Room Temperature

2005 ◽  
Vol 290 ◽  
pp. 336-339 ◽  
Author(s):  
G. Guidoni ◽  
Y. Torres Hernández ◽  
Marc Anglada
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier Coatings ◽  
Room Temperature ◽  
Inconel 625 ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Bending Tests ◽  
Four Point Bending ◽  
Barrier Coating ◽  
Plasma Sprayed

Four point bending tests have been carried out on a thermal barrier coating (TBC) system, at room temperature. The TBC system consisted of a plasma sprayed Y-TZP top coat with 8 % in weight of Yttria, a bond coat of NiCrAlY and a Ni-based superalloy Inconel 625 as substrate. The TBC coating was deposited on both sides of the prismatic specimens. Efforts have been done in detecting the damage of the coating by means of Maltzbender et al [1] model.

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.

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.

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 hafnium addition on a Ni-Al-Co Alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 940-941
Author(s):  
L. S. Lin ◽  
G. W. Levan ◽  
S. M. Russell ◽  
C. C. Law
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Strength ◽  
Grain Boundaries ◽  
Ternary Alloy ◽  
Room Temperature ◽  
Gamma Prime ◽  
Room Temperature Ductility ◽  
Appreciable Increase ◽  
Hf Addition

Recent efforts at P&W have shown that the addition of cobalt to binary NiAl results in an appreciable increase in room temperature ductility. One version of this ternary alloy, designated VIM A, has a composition of Ni-30 at.% Al-35 at.% Co. The addition of 0.5 at.% Hf to this alloy (designated VIM AH) results in an improvement in yield strength at 760°C. Room temperature properties were not found to be significantly affected by the Hf addition. This discussion will focus on the microstructures of alloys VIM A and VIM AH and their relationship to the mechanical properties observed in compression at room temperature and 760°C.The addition of hafnium reduced the grain size of VIM AH alloy. After room temperature compression, both alloys show an ordered bcc (B2) matrix and precipitates which are distributed primarily along grain boundaries. These precipitates were identified by microdiffraction to be ordered fcc (L12) gamma prime for VIM A and hexagonal (A3) for VIM AH.

Microstructure and Mechanical Properties of Dual Multi-Phase Intermetallic Alloys Composed of Geometrically Close Packed Ni3X Structures

2007 ◽  
Vol 561-565 ◽  
pp. 375-378
Author(s):  
Takayuki Takasugi ◽  
Yasuyuki Kaneno
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Ductility ◽  
High Yield ◽  
Intermetallic Alloys ◽  
Two Phase ◽  
Low Temperature Annealing ◽  
Wide Range ◽  
Phase Intermetallic ◽  
Multi Phase

Dual two-phase intermetallic alloys composed of geometrically close packed (GCP) structures of Ni3Al(L12) and Ni3V(D022) containing Nb were investigated in terms of the microstructural evolution during low temperature annealing (aging) and the related mechanical properties. The eutectoid region, i.e. the prior Al phase (Ni solid solution) is composed of the lamellar-like structure consisting of Ni3Al(L12) and Ni3V(D022) phases. The lamellar-like structure tended to align along <001> direction and on {001} plane in the prior A1 phase (or the L12 phase). In a wide range of temperature, the dual two-phase intermetallic alloys showed high yield and tensile strength, and also reasonable tensile ductility, accompanied with ductile fracture mode.

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