The P/M industry and technology are far from mature and continue to evolve. The industry has experienced a wave of consolidation during the past decade and globalization is a growing trend. P/M technology is being pushed to its limits with the development of new processes, equipment, and material systems for the production of new parts that can displace high performance wrought materials.
In 2001, the North American PM industry suffered its biggest one year setback in living memory. The drop in automotive production precipitated a 13% fall in shipments of ferrous and copper-base powders for PM parts production. Business bounced back in 2002 with shipments recovering nearly 44000 of the 51000 tones decline. However, it took until 2004 for a new peak to be reached. On the other hand, the iron powder shipments for US dropped about 16% from 2007 and 2008 while some areas of the PM business have seen as much as 35% sales decline. Downsizing of US auto industry as Asian car producers continue to grow market share means increased 'off-shoring' of parts manufacture. This trend and the decline in the sales of large SUVs and pick-ups as well as the switch to hybrid electric vehicles will partially offset the continuing success of PM application in the automotive sector.
On the other hand, the European PM industry did not suffer the recession in the US and should fare better in the next several years due to the growth of auto-related manufacturing in Eastern Europe. Although automotive production remains static, Japan's decade-long recession in PM industry seems to have come to an end. PM structural parts production reached new high in 2004 for second years with the automotive PM sector showing a third consecutive new high. Meanwhile, PM production in the rest of Asia, led by China has been catching up with Japan and iron powder shipments for PM will likely pull ahead in the near future.
Outside the traditional PM sector involving ferrous and copper base powders, tow main stories both in Asia are apparent. The phenomenal growth in portable electronic equipment- mobile phones, laptop computers, CD players and etc has created a huge demand for rechargeable batteries. Nickel and Cobalt powders are used in some of these batteries whose manufacture is increasingly concentrated in Asia. For tungsten resources, China has long been the world's largest source. With its rapid industrialization, China has begun restricting the export of tungsten minerals and focusing on downstream tungsten products such as cemented carbides, creating pressure on other producers and causing sharp price increases.
From the end of 2008, the economic crisis bring the worldwide PM industry recession. The automotive sectors are the sole focus for many PM businesses. It can be seen that as approximately 70% of iron and steel based PM parts production goes into light vehicles according to industry estimates. The drop in automotive production will directly affect the PM parts makers and metal producers globally.
Powder type
2001
2005
2010(Forecast)
Iron and Steel
897000
1060000
1230000
Copper and Copper Alloy
5500
65000
80000
Tin
2300
2600
3300
Nickel
40000
50000
60000
Aluminum
100000
110000
120000
Tungsten
34000
37000
40000
Cobalt
5000
6000
7000
Table 1: Summary of Global Markets for Ferrous and Non-Ferrous Powder 2001-1010 (tones)
Figure 1: Breakdown of global metal powder consumption by weight 2008
Powder Blending
The non-stop developments in manufacturing technology and production equipment will always provide the global PM industry with the advance tools to produce more complex PM shapes with improved properties. To achieve this, the powder blending plays the important role in the advance processing technology. The current powder blending technology used in the PM industry is dry mixing. This type of powder blending used to produce a homogeneous powder mix by incorporates the base powder. It need some admixed alloying elements and a pressing lubricant if the mixture need to compacted in a rigid die. Basically, the lubricants used in dry mixing machine are stearic acid, stearin, metallic stearates and organic compounds of a waxy nature. Besides that, the dry mixing can use some binding agent such as kerosene, glycol and glycerin to bind the fine admixed alloying powder to the coarser base powder particles. This process can reduce the segregation and dusting during powder handling. On the other hand, it also ensures uniform density in the powder compact. The dry mixing powder blending can divided into two basic types:
Tumble mixers
The powders are rotate about a horizontal axis in the closed vessel. The designer shape of the container make the powder mass can continuously fold over on itself. The shape of the container such as double-cone, V or U shapes and cubes rotating on a diagonal are normally used in the powder manufacturing process. The rotary batch blender is favor used because of the short time needed to produce homogenous mixes. This design with a lifter and baffle creates a four-way mixing action of the powder ingredients in the rotary mixing chamber by make it tumbles and turns in a low intensity process.
Stirrer mixers
The powder blending with a paddle or other devices is fitted inside the container. The cylinder with its axis horizontal in which one or more rotating blades are mounted is called ribbon blade mixer. The cone with its apex at the bottom and Archimedes screw rotates by moves around bodily with a stirring action is called Nauta mixer. In this type of mixer, it able to add a second screw into the latter type to push any 'light' components of the powder mix such as lubricant into the bulk of the powder.
