Comparison between Powder Metallurgy Gear Parts and Machined Gears Made of 45 # Steel Materials

Q:  What is the hardness and strength of powder metallurgy gear parts?

A:  This involves the professional field of powder metallurgy, as the density, porosity, material, and heat treatment method of powder metallurgy gears directly affect the level of hardness and strength. High density, high hardness, small pores, high density, good material, and high hardness of alloy elements. Heat treatment methods generally include carburization quenching, carbon nitrogen co infiltration, high-frequency quenching, low-frequency quenching, oil quenching, etc. Stable and qualified quenching processes ensure stable hardness during heat treatment.

Hardness control for heat treatment of general powder metallurgy products:

Ordinary atomized powder (including carbon steel and copper carbon alloy steel), with a density of 6.9 or above, and a quenching hardness that can be controlled to around HRC30.

Generally, pre alloyed powder (AB powder) has a density of over 6.95, and the quenching hardness can be controlled to around HRC35.

High pre alloy powder (AE powder), with a density of over 6.95, and a quenching hardness that can be controlled to around HRC40.

The density and material stability of powder metallurgy products made of the above materials, as well as the corresponding requirements for heat treatment hardness, will result in their tensile and compressive strength reaching a good peak.

Q:  Can the heat treatment hardness of powder metallurgy reach the heat treatment hardness of 45 steel?

A:  Yes!

However, because the density of powder metallurgy products is not as high as that of 45 # steel, powder metallurgy pressed parts generally have a maximum density of 7.2 g/cm³;. And the density of 45 # steel is 7.9 g/cm³; , Powder metallurgy mandatory carburization or high-frequency heat treatment exceeding HRC45 can cause brittleness of powder metallurgy products due to high quenching, resulting in lower strength of powder metallurgy products.

Let's compare powder metallurgy molded gears with machined hobbing gears:

1. No or minimal cutting required

2. High material utilization rate, up to over 95%

3. Good dimensional consistency, stability, and high accuracy of parts

4. Suitable for mass production, so it has absolute competitiveness in terms of price

5. Due to its suitability for mass production, it has high production efficiency and lower cost compared to cutting processing

6. Powder compression molding adopts mold forming, which can produce complex shaped parts that cannot be made by other cutting and hobbing processes

Comparison of strength: Professional powder metallurgy manufacturers have designed and optimized powder metallurgy molds, and the tensile and compressive strength of the produced gears are close to that of material hobbing gears. For example, the driven gears of automotive gearboxes with high transmission strength are also powder metallurgy gears. Visible practicality and universality of powder metallurgy gears