CASE
STUDY: H.C. Starck
ToughMet®
Alloy Handles "Pressing" Issues
By replacing aluminum bronze, Brush Wellman's ToughMet®
alloy is helping companies like H.C. Starck in Coldwater,
Michigan reduce maintenance time and costs.
H.C. Starck is a producer of a unique assortment of
refractory metal powders, including tungsten, molybdenum,
tantalum, niobium, rhenium as well as their compounds
(borides, carbides, nitrides, oxides, silicides, sulfides).
Additional production focuses on thermal spray and
advanced ceramic powders, nonferrous metals, such as nickel
and nickel salts, as well as boron and boron compounds.
H.C. Starck's location in Coldwater, Michigan began
manufacturing in 1958 and played an essential role in
using the arc cast process. This process is still used to melt
the highest quality molybdenum ingots. In the mid 70s, a
5,500-ton capacity horizontal extrusion press was installed
for extruding arc cast molybdenum ingots. Through the
years, the press has been expanded in scope to provide
toll extrusion services for manufacturing a wide variety
of shaped metal alloys.
Today, H.C. Starck's Coldwater facility provides molybdenum
powders, extrusion services and molybdenum wrought bars
for the glass melting, medical diagnostic, vacuum furnace,
electronic and aerospace markets. The extrusion press offers
toll conversion of refractory metals, superalloys, nickel base
alloys, copper alloys, stainless steels, superconducting
materials, and many other exotic and pure metals into rod,
tubulars and near net shapes.

ALL WORN OUT
A few years ago H.C. Starck began exploring options to increase
up time by extending the life of the ways that support the
30,000-pound hardened steel container on the extrusion press.
The container holds the billet against the die during the
extrusion process. Approximately 300 times per day, the
container slides along the ways allowing operators to lubricate,
clean and change the die between extrusions.
As the ways wear, operators
must re-align the container
and die, requiring the press
to be down for about 1 to
11/2 hours. When the ways
have worn out, H.C. Starck
must shut down the press
to remove and replace
them. Surfaces of ways
made from C95400
aluminum bronze typically
showed about 0.060" of wear after one year of service and
required replacement after about two years.
To combat the wear problem, H.C. Starck replaced the
C95400 container ways with Brush Wellman's ToughMet® 2
CX90. Fifteen months after
installation no evidence of
wear was found. ToughMet
lasts at least twice as long as
C95400, saving about one day
per year in lost production.
"We've been using ToughMet
for about four years and have not seen any appreciable wear
since its installation," said Jim Wodyka, Extrusion Process
and Development Engineer for H.C. Starck. "ToughMet has
only been replaced 2 times since it was installed."
A HARSH DAY'S NIGHT
Adding to the already harsh environment in the H.C. Starck
plant is the use of a high-temperature lubricant, such as graphite
and powdered glass, which can fall and solidify as a particulate
on the ways causing abrasive wear in softer materials. These
extreme conditions have been no match for ToughMet.
"ToughMet's ability to perform in harsh environments has been
extremely impressive," adds Wodyka.
ToughMet® is a spinodally hardened copper-nickel-tin alloy
that combines high strength, lubricity and wear resistance under
severe loading conditions. In comparative sleeve bearing tests
against a hardened steel shaft, ToughMet shows unprecedented
performance for a metallic bearing material.
NOW IT'S OUR TURN
After documenting the success of ToughMet on the extrusion
press at H.C. Starck, the alloy was installed on Brush
Wellman's own extrusion press in Elmore, Ohio. The die
slide is supported by wear pads, which push the slide back
and forth during extrusion. These wear pads were originally
made from C95900 (aluminum bronze) and would wear
about 0.015" - 0.020" every six months requiring that the die
slide be raised to compensate for the wear. Since replacing the
aluminum bronze with ToughMet, the wear pads have already
lasted at least
twice as long
(at the time of
publication),
and are still
going strong.
"A typical
shutdown for preventative maintenance takes at least three
days," said Jim Stein, Production Supervisor at Brush
Wellman's Elmore plant. "We are essentially eliminating our
6-month shutdown by analyzing the alignment once a year
instead of twice and have increased our capacity by 180,000
pounds per year."
Click to View PDF of Full Case Study
Back to ToughMet® Home Page