Surface integrity and fatigue of non-conventional machined Alloy 718

• Alloy 718 is a high-strength, corrosion-resistant nickel chromium-based superalloy frequently used for applications, such as aerospace, marine, nuclear reactor and chemical industries, due to its outstanding inherent properties such as high strength and corrosion resistance at high temperatures together with good creep behaviour. Although, the use of conventional manufacturing processes is prevalent for their use on Alloy 718, alternative manufacturing technologies are gaining importance. This work compares the effects of alternative manufacturing processes, such as Abrasive water jet (AWJ), Wire Electrical Discharge Machining (WEDM) and ultrasound vibration assisted milling (UVAM) with conventional milling during the manufacture of Alloy 718 parts. Surface integrity, hardness, residual stress and fatigue strength obtained from these machining processes have been examined for cutting alloy 718. Results show that both residual stresses and surface roughness are correlated with fatigue strength. UVAM results shown an improvement on the surface integrity of the final workpiece. AWJ and WEDM show poorer results, further work on post-process technologies or process condition selection must be carry out to establish them as an alternative in Alloy 718 cutting operations.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

Keyword

Alloy 718

AWJ

Fatigue

Surface integrity

UVAM

WEDM

Chemical industry

Chromium alloys

Corrosion resistance

Corrosion resistant alloys

Electric discharge machining

Electric discharges

Fatigue of materials

Manufacture

Marine applications

Milling (machining)

Nickel alloys

Nuclear reactors

Residual stresses

Seawater corrosion

Surface roughness

Thermal fatigue

Alternative manufacturing process

High strength and corrosion resistances

Manufacturing technologies

Wire electrical discharge machining

High strength alloys

Production Technology

Manufacturing and materials engineering

Publication and Content Type

ref (subject category)

art (subject category)