Powder-Tech Associates, Inc


Laboratory Services - Prototype Sintered Materials - Development - Consultation

Laboratory Services
Quantitative Image Analysis and Metallography With the quantitative image analysis, we can construct a density map of a part's cross section, to be sure that each area has the intended density. When you can see how the density actually changes inside the part, the compacting tools can sometimes be compensated to cure a problem such as shear lines and high or low density regions. Image analysis can quantitatively measure the roundness of porosity, which is one step in assessing the degree of sinter.

Image Analysis, New Image Pro

Metallography is our most important diagnostic tool. By examining carefully polished and/or etched cross sections of P/M parts, at 50 to 1000X, we reveal processing history. If the part is defective, we are often able to see the cause and suggest a remedy. Typical questions that are answered include:

  • - Why is the part too hard or too soft?
  • - Is it properly sintered?
  • - How does the density vary from point to point, e.g. between two steps, ....over a distance of .010" ?
  • - Is it carburized or decarburized?
  • - Case hardness and depth?
  • - Why doesn't it machine well? like it used to?
  • - Whose iron was used?
  • - Does it contain Cu, Ni, C, MnS, plastic? - Inclusions?
  • - How deep are the cracks?
  • - Why is it blistered?
  • - Are the pores open on the bearing I.D.?
  • - Why did the plating erupt?
  • - How heavy was the steam blackening?
  • - How do we duplicate the processing used on these parts that come in from off-shore?

    Image Analysis, area fraction of pearlite

    Mechanical Tests
    Since 1978, our laboratory has been producing test bars that have been used in generating the data needed to write MPIF, ASTM and ISO material standard specifications. In conducting interlaboratory testing, we mold test bars that are sintered in the participant's facilities. The bars are then tested by our lab, or tested under our supervision. We then metallographically examine and characterize the test bars. The various standardizing committees review the data in our reports, decide on mandatory and typical properties and then issue their standard specifications.

    Our laboratory performs the following mechanical tests on P/M test bars or parts:

    - Tensile strength, .2% Y.S., elongation
    - Transverse rupture strength
    - Rotating beam fatigue endurance limit
    - Microhardness: Knoop, Vickers, HRC
    - Macrohardness: Rockwell and superficial
    - Compressive yield strength
    - Machinability by drilling

    There are special arrangements for Charpy impact, axial fatigue, Young's modulus, shear modulus, Poisson's ratio, Jominy hardenability and wear testing.

    Test Bars

    Test bars can be molded and sintered for the MPIF 10 tensile dogbones, unnotched Charpy bars, and transverse rupture bars, (MPIF 41). Heat treated tensile and rotating beam fatigue bars are machined from the unnotched Charpy bar, which is 10x10x75 mm. As a control measure, our green bars are often sintered by parts producer's, allowing them to show process control.

    960X Photomicrograph, etched structure of a sintered air-hardening low alloy steel.
    Shows mainly tan martensite with some pearlite. Dark areas are pores.

    Physical Tests

    - Density by ASTM B-328, MPIF 42: balances
    are readable to .0001g at 120 g capacity,
    and .1 g at 6,000 g capacity.
    - Open porosity and oil content in bearings
    - Electrical resistivity, %IACS, by Magnaflux,
    or ohm-cm, by Physical Acoustics four point
    probe (AT&T device)
    - Crack detection by Physical Acoustics,
    (AT&T device)

    Powder Characterization

    - Flow rate and apparent density, Hall,
    Arnold, and Carney meters
    - Particle shape and size by quantitative
    image analysis
    - Hydrogen loss by MPIF 02 ASTM E-159
    - Acid insoluble content MPIF 06 ASTM- E194
    - Sieve analysis, MPIF 05, ASTM B214
    - Compressibility, MPIF 45, ASTM B-331
    - Green strength, MPIF 15, ASTM B-312
    - Sampling of powder, MPIF 01, ASTM B-215
    - Dimensional change, MPIF 44 ASTM B-610
    - Non-metallic inclusions in low alloy P/F

    We have the ISO standards for metal powders and parts, and carry out those test methods.

    Development and Engineering
    Powder-Tech maintains a 2,500 ft2 pilot plant which we use in the development of new P/M materials and parts, as well as in making prototype discs and bars. It has powder mixing equipment for lots from 1 to 500 lb, hydraulic presses to 1,000 tons, and both atmosphere sintering to 2100oF in DA and high temperature vacuum sintering, 2500oF. Some examples of development work which we have done include:
    - Tested special additives for wear resistance and anti-galling capability in both press and sinter, and P/F parts
    - Evaluated additives for increased machinability
    - Evaluated powdered lubricants that are mixed with metal powders to aid compaction and ejection of P/M parts
    - Tested additives for self-lubrication such as graphite, MoS2, BN, or Tribaloy T400.
    - Tested new metal powders for compressibility, sintered and heat treated strength, and hardenability .
    (Sintering under good industrial conditions where needed)
    - Developed a simulated MIM material for prototyping and then established the heat treating conditions to form defined depths of case hardening
    - Assisted in developing equipment for crack detection in green and sintered P/M parts.
    - Developed and published data on MIM materials made from coarser powders, and the formation of MIM alloys using masteralloy additions
    - Developed a method to make large high density, high conductivity copper parts
    - Evaluated ceramic die materials for friction involved in compaction and ejection
    - Developed platinum electrode for automated insulin administration
    - Evaluated materials for P/F con rods
    - Developed porous media
    - Preconsolidated powders that were then Hot Isostatically Pressed, HIP'd.

    Prototype Sintered Materials
    A key step in developing a new powder metallurgy (P/M) part is testing the design in prototype form. Because of the time and expense required to build tooling, most P/M houses and end user OEMs rely on test parts machined from sintered blanks. No P/M parts production facility likes to interrupt press runs to make a few prototype bars or discs. Powder-Tech Associates answers this need by being organized to make prototype discs in quantities from one piece to a few hundred pieces, and to ship them in two to four work days. James Collette and David Pease operate our pilot plant and produce the prototype materials. To provide this quick response, they do everything from preparing quotations, to taking orders, mixing, pressing, sintering and shipping. The result is that most P/M houses and many OEM's rely on this service to speed up the development cycle.

    Pilot Plant Tooling

    our facility has round tooling for solid discs in 12 sizes from 1.125" to 6.50" in diameter and 7 sizes of cored disc or rings. There are four sizes of square and rectangular tools from 2.625" square to a 4.4 x 6.5" rectangle. Since we weigh out the powder charge for each piece, thicknesses from .050" to 2.0" are easily provided. By special arrangement, thicker pieces or larger sizes can be made. A price list with all of the our tool sizes is available and the minimum prototype material order is $25.

    Examples of our prototype P/M discs and bars

    Powder Inventory
    We stock from a few pounds to a few tons of all of the usual grades of iron, low alloy steel, stainless steel, brass and bronze. Anything in the MPIF, ASTM, or ISO standards is available. Iron and low alloy steel powders from all of the North American suppliers are always in inventory. To speed up production of your order, we maintain most of the MPIF grades in mixed form. Our mixing is done in batches from a few ounces to 500 pounds, in four different V or double cone blenders. We maintain the usual additives of lubricants, copper, nickel, graphite, and MnS.

    Powder Compaction
    Our round and rectangular dies are mounted in special die sets so that the dies are supported on four air pistons. During pressing, the powder sees true double sided compaction. Press sizes include 700 and 1,000 tons. Molding pressures of up to 50 tsi are routinely used but we use even higher pressure on some tool sets. Where needed, powders can be compacted using die wall lubrication only. For very high density parts, we regularly presinter and then repress the materials.

    We use a 6" diameter, muffled furnace to sinter in dissociated ammonia at up to 2100oF. Our C.I. Hayes vacuum furnace can handle a stack of 6.5" discs, and sinter at up to 2500o F, under program controlled temperature ramps. It usually operates with a 500 micron backfilling of argon or nitrogen to prevent evaporative loss of elements like Cr. Sintering under production nitrogen based atmosphere is done through cooperative arrangement with local P/M houses, while large scale vacuum sintering or hydrogen sintering is carried out locally at HMT or Vac-Hyd.

    P/M houses work with us in several ways: it ranges from just having us compact their powder, to having us do the whole job, including drop shipping the sintered materials to their customer. Some OEMs just specify the MPIF or ASTM grade that is needed. Other OEM's are referred to us, and tell us what material their P/M parts production vendor will be using. The prototype material system works well when our material is very close to that which will be used in production. This means that the prototype's density should be equal to the density that will be found in the critical region of the production part. It also means that after we allow for heat up time in our furnaces, that the prototypes see the same time at temperature as the production parts.

    Prototype MIM Materials
    are offered in most of the tool sizes in our list. The MIM material is simulated in one of several ways. The most convenient method is too double press and high temperature sinter powders such as atomized or carbonyl iron or prealloyed 4600 series. Final density is > 7.5 g/cm3, and is a conservative way to simulate the MIM material.
    Prototype Forged P/F Materials
    are available in the 2.3", 3.0" and 4.0" diameter tools. We mold preforms at 6.7 g/cm3, machine the diameter down to a size which permits the desired lateral flow, sinter, cool, lubricate the parts with graphite, reheat and forge at 55 tsi. Typical iron and low alloy steel discs have less than 1% residual porosity. Tools are preheated to 700 F. Disc thicknesses are 1" to 2".

    Prototype Warm Pressed Materials
    Most of our tools can be heated to 290 F to press preheated steel powder to >7.3 g/cm3.

    The Powder-Tech Family

    Based on their experience in producing P/M parts at two different P/M facilities, Ray Collette and Lanny Pease started Powder-Tech Associates in 1973. As the business grew, during the 1980's and 1990's, they were joined by their sons, James Collette and then David and Douglas Pease. In 1991, after the passing of Raymond Collette, Barbara Pease and her mother Helen Gates assumed the financial management of our company. Barbara is Treasurer and Helen is CFO. Lanny Pease is President. Powder-Tech occupies 3,200 ft2 in a multi-tenant, 16,000 ft2 building.

    Orders for Prototype P/M Materials

    Quotations, orders, and follow-up questions are handled by any one of the group - Jim Collette, David Pease, Douglas Pease, Chuck Flynn, Barbara Pease, or Lanny Pease. Questions about invoices are answered by Barbara Pease or Doug Pease.

    Our separate list of tool sizes and charges can be used to estimate the costs for our prototype materials, but most people find it more convenient to call one of us at 978-685-6027 for an immediate quotation of price and delivery. We try to respond to FAX inquiries as if they were personal telephone calls. If you prefer to FAX us at 978-683-5733, we will get right back to you. We often write our quotations directly on your FAX inquiry, which saves us time and keeps all the important details in one place.

    We entered the era of the Internet in late 1995 with E mail at ptech@shore.net and a web site home page at http://www.powder-tech.com.

    Laboratory Services and Consultation

    Leander (Lanny) Pease manages the laboratory services and consultation, with support from Jim Collette, Douglas and David Pease. Lanny's professional background includes:

    - ScB Physics, MIT
    - MS Metallurgy, MIT
    - ScD Physical Metallurgy, MIT
    - MBA, Northeastern University
    - V.P. Technology, Wakefield Corp.
    - Program Manager, Kennecott Copper
    - Cofounder and V.P. Technology, Sinterbond Corporation
    - Consultant to MPIF and MIMA Standards Committees
    - ASTM B-9 Committee on P/M: past Committee Chairman and Chairman or Secretary of several of its subcommittees
    - Through ASTM B09.09 and ANSI, represented United States in ISO TC 119, SC 3, on methods of test for P/M parts
    - Author of over 25 technical papers and handbook chapters on P/M. (A list of the papers is available and complimentary copies of the papers are provided on request.)
    - Membership in APMI, MPIF, ASTM, EPMA, ASM, AIME, Sigma Xi

    Consultation Services

    Some examples of consulting services which we have provided to our clients include:

    - Assisted in several searches on behalf of prospective purchasers of P/M houses or powder manufacturers
    - Acted on behalf of a large corporation to find a purchaser for its small P/M parts division - Surveyed markets for very large P/M parts
    - Surveyed applications for Fe and other powders
    - Acted jointly with Gorham Advanced Materials Institute on market surveys and strategic planning
    - Expert witness in legal cases; usually based on testing done in our own laboratory or other supporting facilities
    - Presented seminars on how to apply P/M in the design of component parts, including troubleshooting and quality control
    - Presented seminars on how to metallographically examine P/M parts and interpret microstructures to understand the processing which a part has undergone
    - Acted with or on behalf of P/M houses in resolving questions or problems with end users
    - Provided flexible retaining arrangements with OEM's, P/M houses, and powder producers to quickly provide P/M related information.
    - Provided training both on site and in our laboratory, on testing procedures for P/M parts and metal powder
    - Assisted in presenting business plans and opportunities for investment in MIM
    - Reviewed stock offering prior to SEC filing for a P/M business
    - Reviewed the P/M process to be used in manufacturing certain very high production components
    - Surveyed potential P/M vendors for a large OEM consumer of P/M parts

    Printing TV images from microscope

    Examples of Clients Whom We Serve

    We serve about 450 OEM clients who use powder metallurgy parts in the products which they manufacture. The list includes all of the major North American auto and truck producers. In the farm and garden market, suppliers of lawn and garden tractors, tillers, lawn mowers, snow blowers, small engine builders, and transmission suppliers all use our services. Other industry segments and product lines which we serve include: business equipment such as copiers and printers, lock hardware, electric motors, hoists, electric and pneumatic tools, hand tools.

    In addition to the OEM clients, we also provide services to more than 80% of the 225, custom and captive, North American P/M parts producers, and all of the major North American base metal powder manufacturers.

    Used P/M Equipment Newsletter

    In order to help the P/M industry buy and sell used equipment without dealer intervention, we publish a monthly newsletter of equipment that companies wish to sell or buy. It is currently in its eighth year, has 11 pages of listings and is mailed to key persons at 270 companies in the P/M industry. The subscription price is $60./yr, and subscribers can list any reasonable amount of equipment at no extra charge. Ads run until equipment is sold, or up to one year. Subscribers include 225 P/M parts facilities, powder producers, equipment manufacturers and about 20 companies that deal in used equipment.

    Listing of 225 P/M Parts Producers

    We maintain a current list of the 225 North American producers of P/M parts. This includes both the custom producers and the captive facilities. The list provides the name of a key person, (usually the president or plant manager), address, telephone, FAX, and the nature of their business. Complimentary copies are available.

    Powder-Tech : Your P/M Resource

    We encourage anyone with a P/M related question to call us anytime. If we know the answer we will tell you. If we do not know the answer, we will refer you on to someone who probably does. This is a complimentary service that helps our existing clients and allows us to introduce ourselves to new ones. We especially appreciate it when our friends refer people to us who either have P/M questions or need one of our services!

    Institutional P/M Resources

    If you are unfamiliar with the Powder Metallurgy industry, a good starting point is our trade organization, the Metal Powder Industries Federation. They are located at 105 College Rd. East, Princeton, NJ 08540, telephone 609-452- 7700. Powder-Tech Associates, Inc. has been a member since 1973. MPIF publishes texts and monographs on P/M as well as two technical journals. It runs an annual international powder metallurgy meeting and exhibition, with about 200 technical papers presented. During the year, its Technical Board sponsors several short courses on different areas of powder metallurgy. Interested individuals may join the trade organization though its professional organization, the American Powder Metallurgy Association.

    Powder-Tech Associates, Inc.
    31 Flagship Drive, North Andover, Massachusetts, 01845-6194
    Telephone: 978-685-6027 FAX: 978-683-5733
    E Mail: ptech @shore.net
    Internet Home Page: http://www.powder-tech.com

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