2 February 2016

What is Burnishing? Burnishing Tools | Roller Burnishing | Advantages | Applications

Introduction of Burnishing process: 

Burnishing a finish machining process is the plastic deformation of a surface due to sliding contact with another object.

Burnishing can be defined as a process in which a smooth but hard tool using sufficient pressure is rubbed on the surface of the metal.

Burnishing is a polishing and work hardening of a metallic surface will smooth and harden the surface, creating a finish which will last longer than one that hasn't been burnished.

Burnishing tools:

Burnishing process works on a variety of different metals such as stainless steel, aluminium, cast iron, and brass, making available for today's manufacturers a wide variety of burnishing tools. Burnishing can eliminate secondary process which cuts down cycle time an ultimately saves money. Now, let's look at some common burning tool types.
  • Diamond burnishing tools : 
This is one of the most versatile burnishing tools. It can be used on a variety of metals and can produce a dense, smooth surface. Setting up for diamond burning is fast and cost-effective, and secondary processes such as grinding are not needed. Overall, this processing tool is efficient and will show high-quality results. 
  • Multi-roll burnishing tools :
It can offer accurate sizing and can show significant improvements in the surface finish of steel and high ductility materials. They can produce in just one pass 2 to 8 Ra microinch finishes. It can be run on almost any machine tool, CNC or manual lathe. These burning tools can be fully interchanged with burning tools in the Madison style.
  • Carbide roll burnishing tools : 
It can be used so that there is no need for secondary operations this helps to reduce costs significantly. This tools remove any surface impurities and produce a 4 to 8 Ra micro inch finish in just one pass. Feature an economic tool life with the option to recondition the rolls. 

Advantages of the burnishing process:

  • Improves revolution size and finish such as cylinders and conical surfaces.
  • It is possible to burn internal and external surfaces.
  • Improves the hardness of the surface.
  • Increases wear resistance and decrease fatigue and fight corrosion.
  • It also eliminates the processes of grinding and honing that can be expensive.
  • Mirror finish in one pass and accurate sizing, close tolerance and eliminate lapping and honing process too. 
  • Long tool life and no operator skill required. 
  • Machining time is short. 
Most widely used burnishing process is Roller Burnishing.

Roller burnishing:

Roller burnishing is a super-finishing process and cold rolling process without removal of metal. A set of rollers is used to roll on with adequate pressure on the component surface resulting in a fine surface through the planetary rotation of hardened rollers over a bored or turned metal surface. 

In the roller burnishing operation compresses the projections into the indentation thus forming a smooth mirror finished surface. It is possible to burnish any material not exceeding 40 Rockwell Hardness C.

The result of this process is a mirror-like finish with a tough, work-hardened, wear and corrosion-resistant surface. 

Advantages of roller burnishing process:

  • Surface finish is good as a mirror Rz < 1 µm / Ra < 0.16 µm can be obtained. 
  • It is possible to achieve very close and consistent dimensional tolerance.
  • Accurate sizing and short cycle time. 
  • Single-pass operation and very less cycle time are required to complete the job to required surface finish and tolerance.
  • The surface hardens at the same time ensures that the processed surface to become stronger, and more slippery. 
  • Reduces reworks and rejections.
  • No sawdust and residues occur so no noise and damage to the environment. 
  • It is too much economical, low spare part consumption and saves time, money and energy. 

Application of Roller Burnishing Tools:

Bright tools are used in sectors such as
  • Automobile
  • Aircraft
  • Defence
  • Spacecraft
  • Railways
  • Textile
  • Machine Tool
  • Motors and Pump Industry
  • Hydraulic and Pneumatic Farm Equipment
  • Home Appliances 

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