金属成形 (Metal forming)

Metal forming: (mechanical deformation)

金属成型：（基于机械变形）

The forming process involves large (typically compressive) stresses (exceeding yields strength, deforming strength of the metal) to change the shape of the workpiece through plastic (non-recoverable) deformation. Large forces are exerted on the workpiece by a press or hammer through tools called "dies". The desired final part shape may be achieved by using a sequence of progressively shaped dies and loading cycles

成形过程涉及大的(通常为压缩的)应力(超过金属的屈服强度①，变形强度)，以通过塑性(不可恢复)变形改变工件的形状。通过称为「模具」的工具，压力机或锤子在工件上施加很大的力。可以通过使用一系列渐进成形的模具及载入循环，来实现最终期望的零件形状。

Metals used in forming processes should have low yield strength (high malleability and high declivity) to accommodate large plastic deformation without breaking) these properties may be temperature dependent. Lubricants (oil or soap) may be used on dies to minimize friction and wear.

成形工艺中使用的金属应具有低屈服强度（高延展性和高倾斜度）以适应大的塑性变形而不断裂)，这些性能可能取决于温度。可将润滑剂（油或肥皂）用于模具上，以减少成形过程中的摩擦和磨损。

Heating metal workpiece allows accomplishment of metal forming processes with lower forces and power consumption, but the final part is generally of poorer quality.

加热金属工件可以以较低的力与功耗完成成形过程，但最终零件通常质量较差。

Cold working (Room temperature)

Good accuracy, surface finish, repeatability
Strain hardening increase part strength
Controllable directional strength properties of part
Requires high deformation forces, only limited changes in part geometry achievable for each die set.

冷加工 (室温下)

精度好，表面光洁度好，可重复性好
应变硬化②提高零件强度
零件的可控方向强度特性
需要高变形力，每个模组只能实现零件几何形状的有限变化。

Hot working (50%-75% of Tm, Kelvin scale melting temperature) Above "recrystallization" temperature internal structure of metal can reorganize

Requires lower forces than cold working & substantial deformations are possible
May be feasible for metals that are brittle at room temperature
Isotropic strength properties
No strain hardening improvement of length
Poor accuracy, surface finish and repeatability

热加工（50%-75%的Tm，开尔文标度熔化温度）高于「再结晶」温度的金属内部结构可以重新组织。

需要比冷加工更低的力，并且可能会产生较大的变形。
对于在室温下易碎的金属，是可行的。
各向同性强度特性
长度无应变硬化改善
精度差、表面光洁度和重复性差

Warm working: intermediate process; heat part to ~30% of Tm

Force application (forging press or hammer) determines strain rate of forging process ε = v/h

ε can reach values up tp 1000/sec

热加工（中间工序）：将零件加热至~30% Tm

施加力(锻压机或锤子)决定锻造过程的应变速率ε=v/h。

ε可以达到tp 1000/sec以上。

Typical forming methods:

Bulk deformation processes for parts with low surface area/volume (A/V) ratios - forging, rolling, extrusion, drawing.
Sheet metal forming (presswork or stamping) - for parts with high A/V ratio.

典型的成形方法：

低表面积/体积比(A/V)零件的体积变形工艺-锻造、轧制、挤压、拉伸。
金属板成形（印刷或冲压）-用于具有高A/V比的零件。

Forging: Compression of a workpiece between two halves of a die defining desired part shape.

Usually a hot-working process, but some parts can be cold-forged. Dated to ~5000 BC (used to make coins, weapons, jewelry, etc.). Forging parts often require finishing processes (e.g. machining or heat treatment)

锻造：在模具两半之间对工件的压缩，以决定所需零件的形状。

通常采用热加工工艺，但有些零件可以冷锻。公元前5000年（用于制造硬币、武器、珠宝等）锻造零件通常需要精加工工艺（如机械加工或热处理）

Deformation force: force may be applied gradually (forging process) or as an impact load (forging hammer) using open dies, impression dies, or flashless dies.

变形力：可以使用开口模具，压印模具或无闪光模具逐渐施加力（锻造过程）或作为冲击载荷（锻造锤）。

Open dies allow lateral flow of workpiece, while impression dies significantly constrain workpiece shape. Flashless dies prevent flow of excess metal along "parting line" between two die halves - this is called "flash", which must be machined off in flashless forging, workpiece volume must be precisely matched to die cavity volume to prevent underfill or overfill.