New Application: Impeller Blade Casting

Impeller Blade Casting

MES Inc. was proud to deliver, this past quarter, a one of a kind impeller blade castings for axial fans. Material was carefully chosen by the customer because of excellent strength properties at elevated temperatures.

Aluminum C355:

  • Offers excellent castability, pressure tightness and resistance to hot cracking.
  • Has optimal fluidity and solidification shrinkage tendencies.
  • Allows for excellent welding strengths (although in the specific case of this application did not allow any welding.)

Polished finishes can be worthy of excellent engineered components which customers appreciate. These blades were designed and manufactured for axial fans with end application in underground and above-ground mining and power industries.

Material was cast using high vacuum melting casting furnace and high tilt automatic equipment. All parts were then X-ray tested per ASTM E155 with expectation to meet Level 2 near the shank of the blade and Level 4 in other areas. Parts also went through machining with tight tolerance of +/-0.02” expected near the shank of the blade. Parts were required to be heat treated (Tempered T-6) level to ensure heat characteristics. However, part twist geometry was seen to be deforming so parts were quenched after casting.

Post quenching, a reshaping operation was added using special fixture to bend the part to desired tolerance. Tempering was then after reshaping. Reshaping, quenching and base machining were done to ensure part twist characteristics were intact and tolerance requirements were met.

C355.0 can be sand cast or permanent cast. Typical sand casting applications include printing press bedplates, air compressor pistons, water jackets, crankcases, electric motor fans and blowers. Permanent mold castings are developed for aircraft, missile, and other components requiring high strength, and for fittings, impellers, timing gears and aircraft supercharger covers. Automotive applications for this aluminum grade include: passenger car wheels, engine blocks, cylinder heads, spring brackets, transmission cases, and miscellaneous truck and trailer castings.

Application Specifics:

  • Material – C355 with T6 heat treatment
  • Cast Weight – 52 Lbs
  • Post-Machining Weight – 47 Lbs
  • Overall Length – 32.5”
  • Blade Length – 30.6”
  • Porosity Requirements – Level-2 X-ray requirements with some areas allowed at Level-4
  • No distortions allowed along the trailing edge
  • Proper filling of the OD of Shank area
  • Meeting Elongation requirement of 8% on such a long part while meeting T6 mechanical properties