Microhardness and compressive mechanical behavior of L1[sub 2] titanium trialuminides

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02656514· OSTI ID:6520818

Winnicka, M B; Varin, R A ^[1]

---

1. Univ. of Waterloo, Ontario (Canada)

Vickers microhardness and compressive mechanical properties of L1[sub 2] Al[sub 3]Ti + X intermetallics, where X = Cr, Mn, Fe, and Cu, were studied. Compressive tests were carried out at the temperature range from room temperature to 900C. At room temperature, both Vickers microhardness and yield strength (0.2% offset) decrease with increasing the long-range order parameter S. Essentially the same behavior of yield strength is observed at all compressive test temperatures up to 900C. In general, apparent compressive ductility (permanent deformation) increases with increasing test temperature, although with different rates, for most of the alloys, except L1[sub 2] Al[sub 3]Ti + Mn (high Ti), which is characterized by the lowest long-range order parameter S. Compressive ductility increases with increasing long-range order at all temperatures, but the highest rate of increase occurs at high temperatures above approximately 600C and the rate of increase at room temperature is minimal. At low temperatures, deformation-induced microcracks were formed in large numbers in all of the alloys studied, even in the matrix free of preexisting flaws. These microcracks can propagate catastrophically under tensile deformation conditions at a stress level barely approaching 0.2% offset prior to the onset of gross plastic flow, leading to a premature fracture. At high temperatures, the initiation of deformation-induced microcracks is inhibited. The mechanical behavior of L1[sub 2] titanium trialuminides is discussed within a general framework of ductile-to-brittle transition.

• OSTI ID: 6520818
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 24A:4; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CHROMIUM
COMPRESSION
COPPER
CRACK PROPAGATION
CRACKS
DUCTILE-BRITTLE TRANSITIONS
DUCTILITY
ELEMENTS
HARDNESS
INTERMETALLIC COMPOUNDS
IRON
MANGANESE
MECHANICAL PROPERTIES
METALS
MICROHARDNESS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TENSILE PROPERTIES
TITANIUM ALLOYS
TRANSITION ELEMENTS
YIELD STRENGTH