Lapping & Polishing Steel - Case Study

Test Requirements:To recommend the shortest process needed to lap and polish a steel sample.
Component/Material: 1 x steel sample.

Process for polishing Steel components

The Kemet Iron lapping stage is a fast method to produce a flat and evenly graded surface; and by following this with an ASFL-AW silk polishing stage, no other lapping plate is needed. The cloths are simply fixed using a self adhesive backing to the Kemet Iron plate once parts are ready for polishing.
Results: After polishing our sample showed an Ra 0.003

Process Breakdown
Stage	Plate/cloth type	Abrasive type/grade	Process time
1 Lap	Kemet Iron	Type K Standard Diamond slurry	15 minutes
2 Polish	ASFL-AW silk polishing pad	Type K Standard Diamond slurry	10 minutes

Before Lapping Steel

After Lapping Steel

After Polishing Steel

Test Requirements: To produce a mirror polish on Steel components.
Component/Material: 6 off 80mm x 115mm Steel Plates.

Process for producing mirror finish to Steel

We used a combination of conventional lapping for stage 1, followed by diamond polishing for stage 2. Both processes could be performed on a single Kemet 24 Diamond Lapping machine.

Process Breakdown
Stage	Plate/cloth type	Abrasive type/grade	Process time
1 Lap	Cast Iron	Kemox O-800S	15 minutes
2 Polish	ASFL polishing pad	Type K Standard Diamond slurry	12 minutes

Steel plate before lapping

Steel plate after lapping

Steel plate after Polishing

Test Requirements:To lap steel Flow Volume Disc and Ceramic Air Flow Disc to Drg. Both Ra 0.5-1µinch, Flatness 1-5µinch.
Component/Material: 10 x Zirconia Ceramic discs Air flow discs and 10 x 303sst steel flow volume discs.

Process for polishing Steel & Zirconia Ceramic

Machine Type: Kemet 15” diamond lapping/polishing machine
Lap Plate: Kemet Copper
Abrasive Type/Grade: Kemet Diamond Slurry Type K 6 micron Standard
Additional Pressure: 1 x 4Kg hand weight for steel parts. 2 x 4 Kg hand weights for Zirconia parts.

Process Breakdown
Component	Plate/cloth type	Abrasive type/grade	Process time
Zirconia	Kemet Copper	Type K Standard Diamond slurry	12 minutes
SS303	Kemet Copper	Type K Standard Diamond slurry	10-25 minutes

Comments: Both types of parts were processed using a Kemet Copper plate and Kemet Liquid diamond Type K 6 Micron standard. We have produced a process to suit both parts with no need to change the machine set-up when changing from 1 part to another.

Results: Both parts were lapped to generate the surface finish Ra target values. The recommended process successfully meets the Ra requirements. The flatness results show the Kemet process has improved the flatness of the Zirconia pieces, and generated the same finished value on the Steel parts.

Part	Flatness before	Flatness after	Ra produced by Kemet
Air Flow Disc Ceramic	52µinch	11.6µinch	0.275µinch
Flow Volume Disc 303sst	Machined	11.6µinch	0.525µinch

Flow Volume Disc after polishing

Air Flow Disc before polishing

Air Flow Disc after polishing

Test Requirements: To remove 0.25mm from steel rail part and then mirror polish
Component/Material: 6 off 80mm x 115mm Steel Plates.

Comments: It took 90 mins to remove 0.25mm material

Process Breakdown
Stage	Plate/cloth type	Abrasive type/grade	Process time
1 Lap	Kemet Iron	Type K Standard Diamond slurry	90 minutes
2 Polish	ASFL polishing pad	Type K Standard Diamond slurry	20 minutes