Effect of Ti on Microstructure, Mechanical Properties and Corrosion Behavior of a Nickel-Aluminum Bronze Alloy

Propeller is one of the important components of ships and boats that function as motor or boat propulsion. The mechanical properties required in propeller material are high toughness, easy to cast, and good engine capability, as well as good resistance to corrosion and erosion. One of the aluminum alloys that have been widely used in major vessels in propeller systems is the Nickel-aluminum-bronze (NAB) alloy because it has an excellent combination of mechanical properties and corrosion-erosion resistance. Another type of aluminum alloy that is widely used as a machining component is the Al 7075 T651 because it has the highest strength among other aluminum alloys. The mechanical properties of the Al 7075 T651 are directly proportional to the erosion resistance of the propeller which agrees with the pot tester porridge. The higher the value of the erosion propeller failure that occurs also increases with increasing testing rotational speed. For corrosion, a propeller with air testing media at a speed of 1000 rpm which results in significant corrosion products. Keywords: Al 7075 T651, Slurry Pot Tester, Corrosion Erosion

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Mechanical Properties at High Temperatures and Microstructures of a Nickel Aluminum Bronze Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.683.82 ◽

2013 ◽

Vol 683 ◽

pp. 82-89 ◽

Cited By ~ 3

Author(s):

Borpit Thossatheppitak ◽

Surasak Suranuntchai ◽

Vitoon Uthaisangsuk ◽

Anchalee Manonukul ◽

Pinai Mungsuntisuk

Keyword(s):

Mechanical Properties ◽

High Temperatures ◽

Flow Behavior ◽

Aluminum Bronze ◽

Nickel Aluminum ◽

Bronze Alloy ◽

Heat Treated ◽

Different Temperatures ◽

Machine Parts ◽

Nickel Aluminum Bronze

Nickel Aluminum Bronze (NAB) alloys have been widely used in different kinds of machine parts where the superior resistance to corrosion and erosion in saltwater is needed. In this work, mechanical properties at high temperatures and microstructures of a NAB alloy were investigated. First, NAB specimens were prepared as an as-cast ingot and were subsequently heat-treated at 675°C for 6 hours in order to improve microstructure and mechanical properties. The mechanical properties at high temperatures in form of the plastic flow curves of the NAB alloy were characterized by a deformation dilatometer. The NAB samples were compressed at high temperature and rapidly cooled down to room temperature. The deformation temperatures of 825°C, 850°C and 900°C, a strain rate of 0.01 s-1, and a maximum compression strain of 0.4 were considered. The influences of the temperature on flow behavior of the NAB alloy were investigated. The plastic stress-strain curves at different temperatures were compared with regard to the rate of material strain hardening and softening. It was found that the compression stresses decreased with increasing temperatures. Additionally, the resulted hardness and microstructures of the alloy after forming at high temperatures were analyzed.

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