Advanced Manufacturing Technology Research Laboratory (AMTReL)Liverpool John Moores University

SUMMARY OF RESEARCH RESULTS

April, 2012Prepared by: Mr. Pitipong BenjarungrojSupervised by: Dr. Michael M Morgan

INVESTIGATION OF THERMALLY TREATED RECYLED GLASS AS A VIBRATORY MASS FINISHING MEDIA:

Performance and Characterisation

Sponsored by: Vibraglaz (UK) Ltd

Content

Introduction Aims / Objectives Problem Outline Experimental programme Results

Introduction

Mass finishing refers to the process technologies for generating edge and surface finishes on a wide range of metallic and non-metallic materials

Common edge and surface finish requirements include: deburring,

descaling, surface smoothing, edge-break, radius formation, removal of surface contaminants from heat treatment and other processes, bright finishing, pre-plate or coating surface preparation.

Introduction: Mass finishing process

Energy is imparted to the abrasive media mass via a vibratory or rotary means to impart motion to it and to cause it to act on the surfaces. [process control parameters: vibration amplitude, frequency, (rotational speed)]

Common mass finishing processes include: vibratory bowl and linear; barrel, centrifugal barrel and centrifugal disk, and rotating barrel

Fluid (compound solutions) required for lubrication (-lower frictional forces and reduce wear), aid swarf removal, cleaning, ease handling

Introduction: Mass finishing process

Centrifugal barrel

Vibratory Bowl Linear Vibratory

Centrifugal disk

Introduction: Mass finishing media

“Media” refers to the abrasive consumable elements used in mass finishing process.

The common media types include natural abrasives, synthetic random media, preformed ceramic and resin-bonded media, and metallic media.

The composition of a media determines whether it is a cutting or finishing type of media.

Introduction: Mass finishing media

Geometry largely depends on application

Introduction: Mass finishing media

Vibratory Finishing

Thermally Treated Recycled Glass Media

:A Report on outcomes of the first research with this innovative product

Introduction

The media under investigation is produced wholly from recycled glass. In its raw state it is in cullet form. The cullet is cleaned of contaminants and crushed. The cullet is then sieved and subsequently graded in a manner similar to that for abrasive grains. The source of glass is varied but is in general glass scheduled for landfill and most recently is predominantly window glass.

:presently there is very little knowledge of the performance, capability or mechanical characteristics of this media

Introduction

Production control requirements:

- mould technology (and release agents)

- heating rate, critical temperature (Tmax), duration at Tmax, cooling rate / quenching

Each have a strong effect on media quality Secret recipe!

This understanding was not available prior to this research

Introduction

Sample V-Cut media

New Media Benefits6 key features that distinguish it from other media: No binder required Significantly higher percentage of abrasive Density: plastic media < V-Cut < ceramic media Strong green credentials and low environmental impact Recyclable Lower cost

Aim / Objectives

To acquire fundamental understanding of the material characteristics of the new development thermally treated recycled media

To obtain machining data over a range of machining conditions

Establish and compare performance of thermally treated recycled media with conventional media

Help develop new products for industrial usage

Help direct the company in identifying the right media for a given job

Replication methods for surface topography assessment

-identification of cutting edge density

-insight into wear mechanism

Cannot use stylus methods –stylus wear and lack of information on surface features

Materials characterisation

This understanding was not available prior to this research

Replication Jig and housing Microset 101 RTH Gun and Cartridge

Thru section of replica Jig to lay flat the replica for measurement

Cutting edge density: Replication Technique

CUTTING EDGE DENSITY - MEASUREMENT

Uniscan Optical interferometer

Cutting Edge density

Date: 08.06.11Code: A1name: Original - 0 deg

Ra: 120.72 umRz: 1.66 umRq: 167.55 umRt: 1.95 mm

Mesh: 12x12 (144)Sampling: 11.74 umSurface Area: 6 x 6

Total Cutting Edge: 27%cutting edge: 18.75%

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(Larger scale view) Typical surface topography result showing Number of peaks at highest level of the surface

Cutting Edge Density Measurement

Cutting edge measurement data for thermally treated glass media

Bearing Ratio ObservationTypical surface topography results

Bearing ratio results

Ceramic Glass Abrasive Media - Original Fixture 0deg Fixture 90deg

Ceramic Glass vs Strainless Steel at 60 min

Ceramic Abrasive vs Strainless above 60 min

Ceramic Glass Abrasive Media - Original Fixture 0deg Fixture 90deg

Ceramic Glass vs Strainless Steel at 60 min

Ceramic Abrasive vs Strainless above 60 min

Typical surface topography results Bearing ratio results

Bearing Ratio Observation

Media Comparision

Ceramic

Plastic

V-Cut

60x magnification (CAMApp - desktop equipment)

Note Cutting edge density

SEM of Thermally Treated Glass

SEM at 100x magnitude SEM at 1000x magnitude

Performance Assessment

Media Wear rate

Surface roughness , Ra (principal parameter measured)

Brightness observation and Visual inspection (Burr removal)

Cycle times

Performance Assessment

V-Cut media used in studies

Mass Finisher (vibratory tumbler)

used in studies

Mitutoyo--Series 178 SJ 400 Surftests

Surface Roughness

Discussion

media 780 is medium grade cutter / polisher

Results are consistent with published data for conventional media(in-house comparative data being prepared)

Limiting values indicate boundary of performance on particular material

For example: If lower Ra is required with material = aluminium, then different grade (i.e. polisher) would be needed, though this would be achieved at the cost of lower material removal rate

Surface Roughness

Discussion

media 790 performs more as a polisher than media 780

The abrasive action of the media is evident in the early part of the graph – i.e. the cutting edges initially dig into and hence roughen the surfacebefore finishing occurs

This is not so evident with a harder material eg. MS or SS

Comparison study of thermally treated media and conventional media against industrial components

Roughness observation of conventional media and thermally treated media on benchmark materials

Titanium alloy coupon

Brightness observation and Visual inspection

Brass before and after 10 minute of machining using Vibraglaz 790

Brass before machining

Brass after machining

using Vibraglaz 780

Stainless (Virgin)

Mild Steel (machining time 15 minutes)From left to rightMild steel before machiningMild steel machining with Plastic mediaMild steel machining with Vibraglaz 790

Brightness observation and Visual inspection

Aluminium (machining time 15 minutes)From left to rightAluminium before machiningAluminium machining with Plastic mediaAluminium machining with Vibraglaz 790Aluminium machining with Ceramic media

Brass (machining time 15 minutes)From left to rightBrass before machiningBrass machining with Vibraglaz 770

Brightness observation and Visual inspection

Brightness observation and Visual inspection

Crank shaft before machining

Crank shaft after machining

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