ABSTRACT: 0592

Mechanical Properties of Cast Ti-Al and Ti-Al-Cu Alloys

M. KOIKE, Q. GUO, J.P. FORD, and T. OKABE, Baylor College of Dentistry, Dallas, TX, USA

Objective: This study examined the mechanical properties of a series of Ti-Al and Ti-Al-Cu alloys. Methods: Five binary Ti-Al (5-9 mass%) alloys and six ternary Ti-Al (5 and 6 mass%)-Cu (1, 3 and 5 mass%) alloys were prepared in an argon-arc melting furnace. Dumbbell specimens (gauge length: 20mm; 2.8mm dia.) (n=3-4) were cast in a MgO-based mold (Selevest CB, Selec, Japan) using a centrifugal casting machine (Ticast Super R, Selec). Cast specimens were tested for yield strength (YS), tensile strength (TS), modulus of elasticity (E) and percent elongation (El) at a crosshead speed of 0.25 mm/min. Vickers hardness (n=8) was determined at 25痠 (H_S) and 300-500痠 (H_B) from the cast surface. Cast pure Ti, commercially pure Ti (CPTi) and Ti-6Al-4V were used as controls. The data were statistically analyzed using one-way ANOVA followed by Tukey multiple-comparison (a=0.05). Results: Alloying Al (5-9%) did not affect the strengths but did reduce the ductility. Means (SD) for properties of tested alloys are as follows [identical letters indicate no statistical differences (p>0.05)].

YS (MPa)

TS (MPa)

E (GPa)

El (%)

H_S (VH)

H_B (VH)

pureTi

370(10)^a

432(14)^a

990(38)^a

15(0.5)^a

478(68)^a,b

132(6)^a

Ti5Al

619(6)^c,d

715(2)^c,d

1092(49)^a

7.9(0.6)^b,c

526(71)^a,b

271(21)^c

Ti5Al1Cu

672(11)^d,e

759(16)^d,e

1138(66)^a

6.9(0.4)^c,d

528(28)^a,b

288(19)^c

Ti5Al3Cu

792(22)^f

876(8)^f

1164(86)^a

4.5(0.1)^d,e

521(30)^a,b

319(25)^d

Ti5Al5Cu

897(17)^h

959(14)^g

1194(9)^a

2.3(0.4)^e

531(60)^a,b

341(24)^e

Ti6Al

595(20)^c

697(21)^c

1096(62)^a

10.7(2.7)^b

442(92)^b

286(33)^c

Ti6Al1Cu

698(12)^e

788(20)^e

1145(66)^a

6.6(2.7)^c,d

450(52)^b

312(20)^d

Ti6Al3Cu

842(15)^f,g,h

929(17)^f,g

1085(74)^a

3.8(0.1)^d,e

510(57)^a,b

330(15)^d,e

Ti6Al5Cu

893(40)^g,h

921(35)^f,g

1170(105)^a

1.3(0.2)^e

510(17)^a,b

361(19)^f

Ti6Al4V

838(14)^f,g

898(41)^f

1036(127)^a

2.2(0.8)^e

525(25)^a,b

348(14)^e,f

CPTi

463(32)^b

555(27)^b

1063(93)^a

8.7(0.7)^b,c

543(55)^a

185(13)^b

Conclusion: The pro-eutectoid microstructure of the Ti-Cu alloy with solid-solution hardened a grains by Al made the cast Ti-Al(6%)-Cu(5%) alloy comparably as strong as the cast Ti-6Al-4V. This study was partially funded by NIH/NIDCR grant DE 11787.

Seq #96 - Keynote Address and Cast Titanium Alloys and Ni-Ti Endodontic Alloys
9:45 AM-11:15 AM, Friday, April 4, 2008
Hilton Anatole Hotel Grand Ballroom D

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