1.粉末冶金工艺概述Overview of the PM process (Powder Compaction Sintering)

• Densify Powder in order to Create Strength 粉末致密化使之具有一定的强度
Density vs Mechanical Performance
密度与力学性能关系
Cost来自百度文库vs Density零件密度与成本的关系
for various P/M manufacturing methods 不同的PM制造工艺
Industrial Sintering Furnaces 工业烧结炉
Continuous Meshbelt type (< 1150oC) Continuous Pusher type (1200-1300oC) Batch type Vacuum furnaces ( < 1300oC) Sintering time at temperature: 15 - 120 min Capacity 30-600 kg/h Sintering atmospheres: N2/H2 mix gas (90%N2/10%H2 is common) Endo gas, Cracked Ammonia – DA Cooling Convective cooling Forced convective cooling (sinterhardening) 连续网带炉（<1150℃） 连续推杆炉(1200-1300℃) 批次真空炉（<1300℃） 烧结时间：15-120分钟 装炉量：30-600kg/h 烧结气氛: N2/H2混合气体 (常用：90%N2/10%H2) 吸热性气氛，分解氨-DA 冷却 对流冷却 强制对流冷却（烧结硬化）
Powder Metallurgy
Overview Of The PM Process
粉末冶金工艺概述
Powder Metallurgy
What is Powder Metallurgy Process? 什么是粉末冶金工艺？
What is Powder Metallurgy?
PM is an art & science of:粉末冶金是艺术和科学的结合:
Höganäs Powder Production Processes
赫格纳斯粉末生产工艺过程
SPONGE IRON POWDERS 还原铁粉
WATER ATOMIZED IRON & STEEL POWDERS 雾化铁粉和钢粉
Iron Powder Particle Shape
铁粉颗粒形状
Atomized powder 雾化铁粉 Sponge powder 还原铁粉
通过各种不同类型的压机，将粉末压制进刚性的模具, 成形零件
3. Sintering for metallurgical bonding at time & temperature under protective atmosphere in sintering furnaces.
在保护性气氛下，在烧结炉内在一定温度和时间下烧结，颗粒间冶金连接
粉末冶金后处理
Industrial Powder Compaction 工业粉末压制
By Paul Skoglund, Höganäs China Ltd
Powder Compaction粉末压制
Press压机
Compaction Tool 模具
Upper punch 上模冲
Powder
with lubricant
2 C - dissolution (800 - 950C)C扩散4 Cooling (Cooling Rate)冷却
Factors Influencing Sintering 影响烧结的参数
• • • • • • • Temperature Time Atmosphere Material composition Alloying method Lubricant content Sintering history (heating and cooling rate) • • • • 温度 时间 气氛 材料成分
Common brands常见品牌: Dorst, Osterwalder, SMS Meer Gasbarre, Cincinatti Yoshizuka, Tamagawa
Powder Compaction粉末压制
Powder fill粉末填充 Die closure模具闭合 Compaction压制 Ejection脱模
Mechanical type机械压机 Hydraulic type液压压机 20 ton – 2000 ton (max. compaction force) 20～2000吨压机（最大压制力） 2 spm – 30 spm (max strokes per minute) 2spm～30spm压机（每分钟最大冲程） CNC type for complex shape parts 计算机数控压机，生产形状复杂的零件。
Common brands: Cremer, Mahler, Elino, Abbot, Hayes…..
生产厂家: Cremer, Mahler, Elino, Abbot, Hayes…..
Sintered state (bonding between particles)
烧结状态（颗粒间的粘结）
Metal powder compact
金属粉末压坯
Porous metal
多孔金属
Green and Sintered State 生坯和烧结状态
After compaction 压制后
After sintering 烧结后
2 1,8
Powder Forging 2P2S
复压复烧 Cu infiltration 渗铜
Warm Compaction 温压
Relative cost
1,6 1,4 1,2 1 0,8 6,8 7 7,2
粉末锻造
1P1S普通压制
7,4
7,6
7,8
8
Density (g/cc)
Industrial Compaction Presses工业压机
显微结构
孔隙度
Shape
Microstructure
显微结构
Alloying
• Dimensional change
尺寸变化
Homogenization
均质化
Different Type of Sintering
烧结的不同类型
• Temperature (normal < 1150C, high temp sintering)
温度（一般<1150C,高温烧结）
•
State (gas, liquid, solid) 状态（气相，液相，固相） Pressure (pressureless, pressure-assisted) 压力（常压，增压） Activation energy (particle size, shape; alloying system) 活化能（颗粒尺寸，形状，合金体系）
MOVIE CLIP Compaction
Sintering of PM Steels 粉末冶金钢的烧结
Why Sintering ? 为什么要烧结？
Green state (cold welding）
生坯状态（冷焊）
= the state after compaction - before sintering压制后-烧结 前
1. Manufacturing Metal Powders and customized mixes
是制造金属及其混粉的方法
2. Converting to components by compaction in rigid dies using various types of compacting presses.
SEM
Cross section
ASC100.29
NC100.24
Powder Metallurgy
What is the size distribution of Powders used for compaction? 什么是压制粉末的粒径分布？
Powder Sizes粉末尺寸
Coarse grade粗粒径: PM Powder粉末冶金粉末: Medium Fine中等粒径: Fine Powder细粉末: Ultra fine Powder超细粉末: Nano Powder纳米粉末: > 150 microns < 425 microns < 150 microns (15-30% -45 Micron) < 45 microns 10 microns to 1micron 1micron to 0.1 micron 0.1 micron to 0.01 micron
粉末和润滑剂 Tool die 阴模 Core rod 芯棒 Lower punch下模冲
Typical pressure 4 – 8 ton/cm2
常用压力在4-8ton/cm2
Multiplaten Tool Adaptor
多台阶的模具组
Powder Pressing粉末压制
• Shape the Powder into a component with desired geometry 使粉末成形为所设计的零件形状
The Sintering Process 烧结工艺
温度Temp. Sintering Temperature
烧结温度 Sintering Time烧结时间
1 RT室温
2
3
4
Time 1 Delubrication (300 - 700C)脱蜡 3 Sintering (1100 - 1300C)烧结
MIM uses fine powder
金属注射成形所用的是细粉末
Sieve Sizes筛分粒径
MESH目
30 40 50 60 80 100 140 200 230 325
Micron微米
600 425 300 250 180 150 106 75 63 45
PM Process粉末冶金过程
PM Processes - Post Sintering
• 合金方法 • 润滑剂含量 • 烧结过程 (加热和冷却速率)
What Happens during Sintering 烧结过程中发生了什么
• Particle bonding
颗粒粘接 Sintering necks
烧结颈
Size Porosity
尺寸 形状 合金化
• Microstructure
•
•
•
Sinter-hardening烧结硬化 forced convective cooling directly after sintering – creates a hard martensitc structure in a cost efficient way 一种低成本方式，烧结后直接强化对流冷却，形成较硬的马氏体组织。
4. Imparting special properties with post sintering operations
通过后处理，可以得到一些特殊的性能。
P/F, HIP, CIP and MIM are not considered here in definition
粉末锻造，热,冷等静压和金属注射成形是不在此讨论的。