Lecture 05 Flashcards

Flashcards reviewing lecture 05 on non-traditional machining.

Material removal using mechanical energy

Material removal using a combination of brittle fracture, mechanical abrasion, microchipping, and surface erosion.

Abrasive Machining

Machining process where material is removed from a workpiece using numerous small-sized abrasive particles.

Abrasive Jet Machining (AJM)

A machining process where abrasive particles are made to impinge on the work material at a high velocity.

Main Mechanisms of Abrasive Jet Machining

Surface Erosion, Mechanical Abrasion, Micro-chipping, and Brittle fracture

Nozzle-Tip-Distance (NTD)

Vertical distance between the tip of the nozzle and the workpiece.

Water Jet Machining (WJM)

A high velocity jet of pure water is used to erode material.

Abrasive Water Jet Machining (AWJM)

A high velocity jet of water-abrasive mixture is used to erode the workpiece material.

Components of AWJM - Abrasive Jet Nozzle

Water is pressurized and expelled through a sapphire nozzle to form a coherent high-velocity jet. Abrasives are added into a specially shaped abrasive-jet nozzle from separate feed ports.

Components of AWJM - Catcher systems

Basins/plates are used to minimize spray and recover water and abrasive

Ultrasonic Machining (USM)

A non-traditional process in which abrasives contained in a slurry are driven against the work by a tool oscillating at low amplitude (25-100 microns) and high frequency (15-30 kHz).

USM Apparatus Components

Power generator, Electroacoustic transducer, Mechanical amplifier, Sonotrode

Transducer

Converts the oscillating current to a mechanical vibration in USM.

Piezoelectric transducer

This consists of a piece of piezoelectric ceramic and two metal electrodes plated on its surface.

Magnetostrictive transducer

Makes use of a type of magnetic material in which an applied oscillating magnetic field squeezes the atoms of the material together, creating a periodic change in the length of the material and thus producing a high-frequency mechanical vibration.

Mechanisms of material removal in USM

Mechanical abrasion, Microchipping, Surface erosion by cavitation