Technology

Manufacturing Processes

Powder metallurgy is a method for manufacturing metallic parts by mixing and compacting metallic powders and then using heat to bind them together. The processes of products completed and delivered to customers are introduced here.

STEP1

Mixing and Blending

Metallic powders are weighed so that they have a predetermined composition and then mixed uniformly with a mixer. The types and amounts of metals contained vary depending on products.

STEP2

Compacting

The uniformly mixed raw material is placed into a high-precision die assembly that was fabricated in-house, and a single-axis compacting press performs the powder compacting. The product in this state is called a compact (green compact).

STEP3

Sintering

By heating compacts in a sintering furnace to bind metallic particles together, sintered compacts with high strength are completed.

STEP4

Sizing

Sintered parts are put into a high-precision die assembly again and then pressurized with sizing press to impart dimensional accuracy and shapes.

STEP5

Machining

Machining is performed as needed.

STEP6

Post-treatment

Heat treatment and oil impregnation are performed according to the intended use of the products.

STEP7

Inspection

An inspection is conducted to check whether the products offer the precision and properties predetermined by product specifications.
In addition, the appearance of products is confirmed if there is no defect.

STEP8

Shipment

Products that pass the inspection are packaged carefully and shipped to customers.

Benefits of Powder Metallurgy

1. Economic efficiency

Near net shape materials can be manufactured using high-precision die assemblies for products with complicated shapes, thus raw material and machining costs can be reduced.

2. High productivity

Continuous compacting is possible using die assemblies; therefore, mass production and superior yield can be achieved.

3. Uniqueness

Products are manufactured from metallic powders; therefore, changing their compositions imparts mechanical properties that meet customer demands to products. In addition, controlling the metallographic structures according to manufacturing conditions makes it possible to respond to different applications.

Comparison with Other Manufacturing Methods

Item		Part manufacturing method
Item		Powder Metallurgy	Forging	Casting	Stamping	Injection molding	Cutting and polishing
Shape	planar complexity	◎	○	○	◎	◎	◎
	steric complexity	◎	○	◎	–	–	◎
	Composite and integrated	–	–	–	◎	◎	–
Productivity	100 pcs or less	–	–	◎	–	–	◎
	3,500 pcs	◎	◎	○	○	○	–
	5,000 pcs or more	◎	○	–	◎	◎	–
Uniqueness	Porosity	◎	–	○	–	–	–
Uniqueness	Specialized composition and metallographic structure	◎	○	○	–	–	–
Precision	Several hundreds of millimeters or more	○	○	◎	○	○	○
	Several tens of millimeters	◎	◎	○	○	◎	◎
	Several millimeters or less	◎	○	–	◎	◎	◎
Weight	Several hundreds of grams or more	○	○	◎	○	–	○
	Several tens of grams	◎	◎	–	◎	◎	◎
	Several grams or less	◎	–	–	◎	◎	◎
Material	High melting point and high reactivity	◎	○	○	–	–	–
Material	Amorphous and rapidly solidified	◎	○	◎	–	–	–
Mechanical properties	Strength	○	◎	○	○	–	◎
	Toughness	○	◎	–	○	○	○
	Hardness	○	○	○	○	○	○
	Wear resistance	○	○	○	–	–	–

◎：Very characteristic advantage
○：Advantage

Product Development

Diamet has developed, manufactured, and sold sinter metal components consistently since its foundation. Powder metallurgy is a simple manufacturing method where powdered metals are mixed, compacted with a press, and sintered to finish.

However, the compacting pressure and sintering temperature need to be changed according to the types and amounts of powders to be mixed, and our technologies are fully used in each process. In addition, manufactured materials and products have characteristics suitable for respective purposes and applications.

A wide variety of metals can be mixed, and we adjust the powder formulations for the respective products.
The Development Department focuses on a wide variety of themes ranging from the selection of raw powder materials to new technologies and manufacturing methods and strives for development that realizes the required performances and functions to meet customer demands.