US 2019/0094162 A1Published application

Method for testing phase transformation point of aluminum alloy

AssigneeCentral South University

InventorsHongying LI, Jiaojiao LIU

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Abstract

A method for testing a phase transformation point of aluminium alloy, comprising cutting an aluminium alloy material to obtain at least three samples to be tested; performing heat treatment on a first sample to be tested to obtain a first resistivity-temperature curve; respectively performing quenching treatment and annealing treatment on a second sample to be tested and a third sample to be tested to obtain the second sample to be tested at a quenched state and the third sample to be tested at a fully annealed state, and respectively heating the second sample to be tested at a quenched state and the third sample to be tested at a fully annealed state to obtain a second resistivity-temperature curve and a third resistivity-temperature curve; obtaining a relative resistivity-temperature curve; and determining a phase transformation starting temperature and a phase transformation termination temperature of the sample to be tested according to the relative resistivity-temperature curve. By means of this method, a phase transformation behavior and a phase transformation temperature under a non-linear cooling condition can be tested. The range of a cooling rate which can be tested in the method is wide, and a phase transformation behavior of a small volume fraction and precipitated phase information about a small size can be captured.

Claims10

Dependent claims

A method for testing the phase transformation point of an aluminum alloy, wherein it comprises the steps of:

cutting an aluminum alloy material to be tested according to a preset size to obtain at least three samples to be tested;
performing heat treatment on a first sample to be tested to obtain a first resistivity-temperature curve of the first sample to be tested during the cooling process of the heat treatment;
performing quenching treatment and annealing treatment on a second sample to be tested and a third sample to be tested, respectively, to obtain an as-quenched second sample to be tested and a fully as-annealed third sample to be tested which are then heated, respectively, to obtain a second resistivity-temperature curve and a third resistivity-temperature curve;
obtaining the relative resistivity-temperature curve according to the following formula:
ρ
e
=
ρ
AQ

(
T
)
-
ρ
i

(
T
)
ρ
AQ

(
T
)
-
ρ
FA

(
T
)
,
wherein ρAQ(T) is the resistivity at temperature T of the as-quenched second sample to be tested which is obtained according to the second resistivity-temperature curve;
ρFA(T) curve;
is the resistivity at temperature T of the fully as-annealed third sample to be tested which is obtained according to the third resistivity-temperature curve;
and ρi(T) is the resistivity at temperature T of the first sample to be tested during the heat treatment which is obtained according to the first resistivity-temperature curve;
and determining the phase transformation starting temperature and the phase transformation termination temperature of the sample to be tested according to the relative resistivity-temperature curve.

36 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/079,207Filed 9 Mar 2016
Published: 28 Mar 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01N 25/12
By investigating changes of state or changes of phase; by investigating sintering: of critical point; of other phase change
G01N 33/20
Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00: metals
C22F 1/002
Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working: by rapid cooling or quenching;…
C22F 1/04
Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working: of aluminium or alloys based thereon