nontrad Machining & Thermal Cutting Processes

nontrad machining

processes that remove excess material by techniques involving mechanical, thermal, elec., or chem energy (or combinations of these energies). Do not use a sharp cutting tool in the conventional sense

Importance of Nontrad. Process

Need to machine hard and non-metals with special properties that make them difficult or impossible to machine by conventional methods

Mechanical nontrad. process

mech. erosion of work material by a high velocity stream of abrasives/fluid (or both)

Electrochemical nontrad process

electrochem energy to remove material (reverse of electroplating)

thermal nontrad. process

thermal energy applied to small portion of work surface causing that portion to be fuse and/or vaporized

Ultrasonic Machining (USM)

abrasive particles contained in a slurry are driven at high velocity against work by a tool vibrating at low amplitude and high frequency (20kHz). Tool oscillation is perpendicular to work surface

USM Applications

- Hard, brittle work materials such as ceramics, glass, and carbides

- Also successful on certain metals, such as stainless steel and titanium

- Shapes include non-round holes, holes along a curved axis

- "Coining operations" - pattern on tool is imparted to a flat work surface

Would USM be effective for ductile materials?

Bad, it is intended to microchip small particles, using micro-cracks to remove ductile material tends to deform rather than break.

Does material have to be electrically conductive?

No

Benefits of USM?

a. capable of machining hard / non-conductive materials

Downsides of USM?

Low material removal rate, and tool wear

Water Jet Cutting (WJC) Process

uses high pressure, high velocity stream of water directed at work surface for cutting.

Usually automated by CNC (comp numerical control) / indust. robots to manipulate nozzle along desired trajectory

Water Jet Cutting Use

Used to cut narrow slits in flat stock such as plastic, composites, floor tile, carpet leather and cardboard. (not suitable for brittle material (glass)

water jet cutting (WJC) advantages

no crushing or thermal damage of work surface, min material loss, no environmental pollution, ease of automation

Abrasive Water Jet Cutting (AJWJC)

When WJC is used on metals/hard materials abrasive particles usually are added to jet stream. Such as aluminum oxide, silicon dioxide, and garnet (silcate mineral).

Abrasive Jet Machining (AJM)