Vacuum Hardening and Carburizing Systems

 

ALD Vacuum Technologies AG the parent company of ALD Thermal Treatment Inc. developed the high pressure gas quenching process in the early 90’s and since then stayed at the forefront of this technology.

Vacuum Carburizing Technology

 

Vacuum Carburizing and High Pressure Gas Quenching offers many advantages, which makes it an attractive alternative to today’s gas carburizing and oil quench technology.

 

Significant Characteristics of this Process Technology are:

 

1.       Environmentally and workplace friendly.

2.       Improved product quality.

3.       Cost savings regarding the complete manufacturing process chain due to less distortion.

 

1.  Environmentally and workplace friendly:

 

Due to gas quenching

  • No washing machine, no washing water disposal.
  • No maintenance or disposal of washing chemicals.
  • No complicated washing water chemistry.
  • Space savings.

Due to the use of “vacuum”, inert gases and minimal quantities of carburizing gas (l/h)

  • No fire precautions, no sprinkler required.
  • No automatic smoke vents in the roof.
  • No oil resistant floors and surfaces required.
  • No toxic gases with CO component.
  • No explosion hazards, no open flames.

 

 2.  Improved product quality:

 

Bright and shiny parts after heat treatment due to: 

  • Clean process with inert gases.

Highest repeatability / reproducibility due to: 

  • Precision of the process
  •  (ECD uniformity of +/- 0.05 mm or 0.002”)

 

Higher fatigue strength and wear resistance due to:        

  • NO intergranular oxidation at the surface,
  • Higher consistency of case depth between tooth root and tooth flank,

    ECD @ tooth root/tooth flank*

  • VC + Gas Quench:        80 – 90 %
  • VC + Oil Quench:          70 – 75 %
  • Gas + Oil Quench:         < 70 %
  • Greater depth of hardness > 58 HRC in tooth root and tooth flank.
  •  *depending on the part size.

3.  Cost savings regarding the complete manufacturing process chain due to less distortion:

 

 

Due to optimal controllability of the quenching process by:

A.  Single-phase heat transfer during quenching

B. Control of quenching intensity:

  • Free choice of gas pressure (from 1 to 20 bar).
  • Free choice of gas speed (2 speeds of the quenching fan).
  • Using different gases (Helium, Nitrogen).
  • Results in less deviation in distortion. (Quenching as hard as necessary).