大多数齿轮、连杆、摇臂及其它高强度金属零件都是用粉末冶金法或用热轧钢材及铸锭锻造的方法制造的。这些制造方法各有其优点,但每种方法在制品性能或制造成本方面也都有它的缺点。用常规方法制造的锻件,具有较高的机械性能,但会产生大量的毛边。同时,铸锭或轧材的缺陷也会影响到锻件质量。粉末冶金的零件可以具有很复杂的形状(常常不需机械加工),成分能控制得很准确,机械性能是各向同性的。但冲击韧性通常比锻件低。粉末冶金法的其它缺点是金属粉末的成本较高,并且其制造过程很复杂。 Most gears, connecting rods, rocker arms and other high-strength metal parts are made by powder metallurgy or forged with hot-rolled steel and ingot. Each of these manufacturing methods has its own advantages, but each method also has its drawbacks in terms of product properties or manufacturing costs. Forgings made by conventional methods have high mechanical properties, but produce large amounts of burrs. At the same time, defects in ingots or rolled stock also affect the quality of the forgings. Powder metallurgy parts can have a very complex shape (often without machining), composition can be controlled very accurately and the mechanical properties are isotropic. But the impact toughness is usually lower than the forging. Other disadvantages of the powder metallurgy method are the high cost of the metal powder and the complicated manufacturing process.