The alloy content and grain size dependence of flow stress in Cu-Ti alloys

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Acta Materialia

DOI:https://doi.org/10.1016/1359-6454(95)00358-4· OSTI ID:271772

Nagarjuna, S; Srinivas, M ^[1]; Balasubramanian, K ^[2]; Sarma, D S ^[3]

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1. Defence Metallurgical Research Lab., Hyderabad (India)
2. Non-Ferrous Materials Technology Development Centre, Hyderabad (India)
3. Banaras Hindu Univ., Varanasi (India). Dept. of Metallurgical Engineering

The effect of grain size and titanium content on the flow stress was studied at room temperature for solution-treated Cu-Ti alloys. It was found that the Hall-Petch relation is valid for the four compositions tested: Cu-1.5 wt% Ti, Cu-2.7 wt% Ti, Cu-4.5 wt% Ti and Cu-5.4 wt% Ti alloys. The Hall-Petch constants {sigma}{sub o{epsilon}} and k{sub {epsilon}} in the equation: {sigma}{sub {epsilon}} = {sigma}{sub o{epsilon}} + k{sub {epsilon}}{center_dot}d{sup {minus}1/2} increase with increasing strain as well as Ti content, {sigma}{sub o{epsilon}} and k{sub {epsilon}} are related to strain ({epsilon}) in such a way that {sigma}{sub o{epsilon}} is proportional to {epsilon} for 1.5 and 2.7 wt% Ti alloys, and {epsilon}{sup 3/2} for 4.5 and 5.4 wt% Ti alloys, while k{sub {epsilon}} is proportional to {epsilon}{sup 1/2} for all four alloys. Considerable increase in yield strength has been observed with increasing Ti content at a common grain size. The increase in yield strength in high Ti content (4.5 and 5.4 wt% Ti) alloys is associated with solid solution strengthening, grain size strengthening as well as fine scale precipitation, first as a mottled structure in Cu-4.5 wt% Ti, and then as a metastable, body-centered tetragonal Cu{sub 4}Ti phase, {beta}{prime} in Cu-5.4 wt% Ti alloy, formed during quenching itself.

• OSTI ID: 271772
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 6 Vol. 44; ISSN XZ504Y; ISSN 1359-6454
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
COPPER ALLOYS
DISLOCATIONS
FLOW STRESS
GRAIN BOUNDARIES
GRAIN SIZE
INTERMETALLIC COMPOUNDS
PRECIPITATION
SOLID SOLUTIONS
STRAINS
STRESSES
TITANIUM ALLOYS
YIELD STRENGTH