Brake Arm Gear PM Sintered Part
In the production of powder metallurgy gears, the higher the material density, the higher its physical and mechanical properties. In other words, the density and distribution of powder metallurgy gear components will determine the performance of the product. Therefore, during the debugging and pressing process of powder metallurgy gear molds, the density of a single box is a must-test item.
Product Introduction
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Brake arm gear PM sintered part |
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Item |
Material |
Production Process |
Sintering Temperature |
Mold |
Custom |
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Brake arm gear powder metallurgy |
440c |
Powder metallurgy |
1550℃ |
To be customized |
Yes |
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Chemical composition |
C ：0.95～1.20 Si： ≤1.00 Mn： ≤1.00 S ： ≤0.030 P ： ≤0.035 Cr：16.00～18.00 Ni：allowed to contain ≤0.60 |
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Available Materials |
Low carbon stainless steel, titanium alloy (Ti, TC4), copper alloy, tungsten alloy, hard alloy, high temperature alloy (718, 713) |
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Product advantages
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Smoothness |
Dimensional accuracy |
Product density |
Appearance treatment |
Appropriate weight |
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Roughness 1～5μm |
（±0.1%～±0.5%） |
92～95% |
Mirror reflection |
0.03g～400g） |
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Mechanical properties |
Hardness: annealed, ≤269HB; Quenching and tempering, ≥58HRC Mechanical behavior: Internal stress (250 N/mm2) Tensile strength (560 N/mm2) EL(18%) HB(250) |
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Heat treatment |
1) Annealing, slow cooling at 800～920℃; 2) Quenching, oil cooling at 1010～1070℃; 3) Tempering, rapid cooling at 100-180°C; 4. Preheating temperature, 649°C-816°C. |
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In the design of powder metallurgy gears in the pressing process, compaction defects will occur due to analysis of various problems and causes, resulting in the scrapping of powder metallurgy parts in our country. So, what defects often appear in the powder metallurgy gear compaction process?
1. The compact density does not meet the design requirements
In the production of powder metallurgy gears, the higher the material density, the higher its physical and mechanical properties. In other words, the density and distribution of powder metallurgy gear components will determine the performance of the product. Therefore, during the debugging and pressing process of powder metallurgy gear molds, the density of a single box is a must-test item. In the density test, it should be noted that the different structures and requirements of the pressure blank should be treated differently.
2. The size of the round sample does not meet the requirements
Radial dimension or pitch is unqualified
2.1 There may be problems with mold design or manufacture. If the error can be eliminated by adjusting the process (that is, by adjusting the powder composition, compact density, sintering process, etc.). ). It can also be remedied, otherwise only the mold will be scrapped.
2.2 Unqualified for different dimensions in the axial direction
You can adjust and stabilize the axial dimensions for non-stepping cylindrical breast blanks, adjusting powder, changing compactions or extending hold times, etc. For the step pressure blank, adjust the forming position of the combined die punch, the powder ratio of each station, the running speed of the floating die punch, etc., to change the height of the step.
3. Shape and position tolerance out of tolerance
3.1 Straightness
The reasons for straightness out of tolerance include: out of mold straightness, uneven density distribution of green body, uneven wall thickness of green body, etc.
3.2 Parallelism
The reasons for an out-of-tolerance parallelism include: out-of-tolerance parallelism of the mold, uneven powder filling, etc.
3.3 Concentricity
The reasons for the difference in coaxiality are: the precision of the mold is too low, the precision of the pressing tools and equipment is low, the installation of the mold does not meet the requirements, and the dress is not uniform.
When the powder flow rate is appropriate, the mold accuracy meets the design requirements, and the pressing tooling and equipment accuracy meet the installation requirements, the shape and position tolerance is mainly related to the density distribution of the compact. When the pressing method is determined, the density distribution of the compact is directly related to the powder filling effect. .
4. Unqualified appearance
High roughness, excessive burr data, dropped edges and corners, roughness and cracks are all common defects in our compact design.
The above is an introduction to the defects generated during the forming process of powder metallurgy gear blanks. There are many defects in powder metallurgy blank forming, but they will lead to product scrapping. The defects that are not easy to find are: uneven density and blank cracking, so special attention should be paid.
Qinhuangdao Zhongwei Precision Machine Parts Co., Ltd. is a professional company that produces and operates powder metallurgy structural parts and powder metallurgy gear series products. Welcome to buy!
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