Chemical machining involves locally melting metal materials using a diluent. It allows for machining surfaces with complex shapes at high accuracy and quality in a way that is independent of the material's hardness or toughness. The process involves applying a mask with holes to the material, then melting the exposed areas of the material where the holes are using a diluent. The time needed for machining depends only on the desired depth of machining, not the size of the surface, with typical speeds of 0.01 to 0.5 mm per minute and the mask resisting outlining for around 8 hours. Materials like copper and bronze are easily melted and good for chemical machining, while chrome, gold and tungsten are harder to

1. BY: SUKHVINDER
S BHATIA

2. Chemical machining
Local melting of material by suitable diluent.
 Machining of metal materials,
 Removing speed of material independence on
hardness and on toughness,
 Surfaces with complicated shape with high
accuracy and quality,
 Here is no originated heat and mechanical
influence area,
 Large areas – more economical than milling

3. Chemical machining
1 – base material,
2 – mask,
3 – holes carved out of mask,
In the place of holes the material is melted by
influence of diluents.

4. Material machinability
Four groups of materials by chemical machinability:
 Copper, bronze – easy they are melted, good
machinability by chemical machining,
 nickel, zinc, aluminium
 manganese, molybdenum,
 chrome, gold, wolfram – they are hard melted, bad
machinability by chemical machining

5. Workpiece preparation for chemical machining
 Grease removal and surface cleaning –
removing the allochemicals from surface and
oxidic coats too (Al alloys – AL2O3 coat), dipping
into 5% medium NaOH and next into 30% medium
of acid of nitride,
 steeping – increasing of mask adhesion, dipping
into medium H2SO4 and next duochrom of
patassic,
 masking – coating resisted on influence of diluent
(resin, enamel) thickness till 2 mm.

6. Workpiece preparation for chemical machining
 Mask drying – mask coating is drying 6 till 8
hours, it can be accelerated in the furnace (small
workpieces),
 Engraving of mask – into drying mask are created
holes (hand engraving, engraving by laser ...),

7. Time needed for machining
 It is independence on the size of the machined
surface,
 It is depend on depth of machining only,
 Speed of outline 0,01 till 0,5 mm/min.,
 mask resisted to outlining approximately 8 hours.

8. Machining by active substance

9. Machining by active substance
Machining shape difficult surfaces.
Semi-solid substance of cellulose (electro gel)
impregnated by acid is attach to the workpiece
surface. In the place of contact the workpiece is
melted.
Is possible to achieve step by step removing until
depth 10 mm. Dimension accuracy is from 0,02 to
0,07 mm.
For acceleration of process is possible to connected
electric voltage until 10V