Feature article: PIM International, Vol.5 No.1 March 2011, pages 28-36, 5572 words

Author: Prof. Randall German, San Diego State University

Associate Dean of Engineering, San Diego State University, San Diego, California 92182-1326, USA

  

---

After several decades of cautious and discreet interest in Powder Injection Moulding, there now appears to be a growing level of enthusiasm for the technology from the commercial and military aerospace industries.

In the following exclusive report for PIM International, Prof. Randall German explores the history of MIM and CIM in aerospace component fabrication, and outlines the challenges that are faced by producers to succeed in the market. A number of noteworthy aerospace components are presented.

Introduction

Aerospace component fabrication using metal powder injection moulding (MIM) traces back to the late 1970s. This application area was one of the first to employ MIM. However, after a burst of early demonstration successes, the penetration of MIM into commercial and defence aerospace markets has been relatively slow. That may change soon as evidenced by increased research and development activities, increased awareness, improved quality systems, and a need for new application areas that differentiate from commodity MIM products.

This article traces the history of powder injection moulded aerospace materials and applications to provide a status report on prospects. Several opportunities are evident in the next few years. The downside is that significant investment is required to take on some of the large, longer-term projects, largely because qualification testing requires about three years of effort. A balance between technical developments and market management is envisioned to bring about significant gains in aerospace applications.

Applications

Aerospace applications for powder injection moulding are not new. The first two MPIF awards for metal powder injection moulding (MIM) were a screw seal used on a Boeing aircraft and a niobium alloy thrust-chamber and injector for a liquid-propellant rocket engine developed under US Air Force contract for Rocketdyne [1]. Indeed, for several years Rocketdyne maintained its own MIM facility. The early successes, by actors such as Ray Wiech, Ron Rivers, and Stan Zalkind, led to a proliferation of larger-scale developments, many of which are evident in the more than 360 firms that practice PIM today.

By the early 2000s, alumina and silica ceramic casting cores used in the fabrication of jet engine turbine blades became a dominant application for PIM. The alumina cores were highly valued since they enabled the directional growth of elongated or single crystal superalloy blades with precise internal cooling passages. Even today casting cores remains the single largest commercial use of PIM and two new facilities have opened in recent years; Chromalloy in Tampa, Florida and ENGIMICS in Ticino, Switzerland.

To properly appreciate the importance of the aerospace casting core field (and the related applications in industrial gas turbines and marine turbines), consider that a typical casting core ranges in cost from $10 to $100. The higher cost is associated with the more precise cores used for the highest pressure regions in the turbine..........

 

Further sections of this paper include:

• History
• Current activities
• Technology status
• Manufacturing quality systems
• Business development
  
• Future opportunities
• Growth strategy
• Summary
• Author
• Acknowledgements
• References

 

Figures and Tables:

Fig. 1 The global annual sales history in millions of dollars for powder injection moulding (upper black curve) and for metal powder injection moulding (lower red curve) since statistics were first collected in 1986. For 2010 the total PIM sales were just short of $1.1 billion
Fig. 2 Sales partition by metallic materials based on percent value of product sold (not tonnage), showing how stainless steels continue to dominate MIM applications
Fig. 3 Examples of alumina casting cores, which meet the rigors of PIM manufacturing for aerospace and represent a large market segment
Fig. 4 One example of a large MIM superalloy component, known as the flow body, it was widely touted as a success, but failed to reach production
Fig. 5 A superalloy turbine wheel demonstration component for small jet engines
Fig. 6 A superalloy valve plate fabricated using MIM
Fig. 7 A demonstration turbine component, about 200 mm in outside diameter

Table 1 The primary MIM aerospace materials processed today
Table 2  Selected superalloy tensile property reports
Table 3  Examples of aerospace MIM applications ranging from routine to life-critical components in roughly increasing sophistication

 Search all documents in the PDF Store 

Search

Search store

Please note that this search only covers document title, introduction / abstract, table / figure captions and author details, as available to view on each document preview page.

 Or view by topic

• Markets, sectors & regions
• Binders feedstock & powders
• Processing PIM parts
• Company Reports