Thermal Strain of Thermally Cycled Alminum Alloy Composites ��

(1)

��

� � � � * � � � � � � �

^**

Thermal Strain of Thermally Cycled Alminum Alloy Composites

Naoya HAGIHARA* and Masakatsu SHIBATA**

Aluminum alloy composites reinforced with aluminum borate particles (ABp) were thermally cycled between 293K and Tmax = 573K, 673K and 773K. Composites thermally cycled at Tmax = 573K and 673K were contracted by 1,000 cycles, but after that expanded with increasing the number of thermal cycling. Composites thermally cycled at Tmax = 773K uniformly expanded with increasing the number of thermal cycling. The thermal strain on thermal cycling of composites reinforced with ABp is less than that of composites reinforced with aluminum borate whiskers. The HR-TEM observation revealed that an ABp was composed from super fine particles. The finite element method analysis assumed the plastic deformation was caused in the composites heated from 273K to 573K.

Key words: aluminum alloy composites, aluminum borate particles, thermal strain, thermal cycling,

��

�

��

�� A6061 ��Al-Si-Mg��

��

(9Al₂O₃�2B₂O₃)��

��

��, �

��(1)��(2)��(3)��

��(4)��Al2O_��

��(5)��

��¹^��

��

��SiC��

��

�� 10 �

��(2)��

��(3)��(4)��

��

��²^��

��

��, ��

��. ��

��

��, �

��,

��.

��

��, ��

��

�1 ��(1)��

��

�� 18 �8 �31 �

�� 3 ��

��

(2)

�.

��

��8�m ��⁴^��

�� VF�60��

��

(1) ��75g ��250ml

��

(2) �� 5

�15ml ��3 ��

(3) ��100ml ��0.1�0.5g

��

(4) �� 100ml ��

0.005�0.07g ��, ��

��

(5) ��60mm��240mm ��

�� 20 ��

��

(6) ��

��353K ��

��

��, ��

��

(1) 1073K ��573K ��

��

(2) �� 1073K ��

��

(3) ��

573K ��

(4) ��

�44MPa ��5 ��

�� 60mm, ��

30mm ��

��

��, ��

��4.5��41��3.5��

��. ��

��AC ��

��

��Tmax = 573K�673K�

773�� 8 ��

��5 ��

��

��. ��

��

��3 ��

��

��TEM��

��HR�TEM��

��

��,

��

��30mm�10mm�4mm ��

��

��, ��10

�30�m ��

��, ��

��154 ��

��

��6.0kV��6.0mA ��

��

� ��

��

��ANSYS ��, ��

��

(3)

��

� �� 4��

4.47��Table 1 ��

��1/8 ��xy� yz�xz ��293K ��573K ��

��6 ��

��3256 ��

Table 1 Physical and mechanical properties of aluminum alloys and aluminum borate particles.

��

�

��

�� 23.6�10^-6/K 4.2�10^-6/K

�� 310MPa 7.8GPa

�� 69.7GPa 392.4GPa

�� 0.33 0.2

� � � � � ��

��

��, ��

��100g ��,

��

1) ��75g 2) ��15ml

3) ��0.5g 4) ��0.06g

��

��25MPa�75MPa��

��6�15ml ��

��

1) ��44MPa

2) ��15ml

��

��Fig. 1

��

��573K�673K ��

��

573K �30 ��

��

�

��

Fig. 1� Dimensional changes of the composites reinforced with the aluminum borate particles on thermal cycling.

Tmax = 773K ��

��1000 ��0.3��3000 �

�� 0.4��500 �

��

��4000 ��2 ��

��

Tmax = 573K�673K ��

��1000 ��

��

��573��

��

��, ��

��

(4)

��

�

��

Fig. 2 ��⁵^��

��

Tmax = 573K, 673K ��, ��

��, ��

��. Tmax = 773K

��, ��

��200 ��

��,��,

1000 ��

��.��

��

��, ��

��.

��

TEM ��HR�TEM ��

Fig. 3 ��

��

��.

��

�

��

Fig. 2 Dimensional changes of the composites reinforced with the aluminum borate whiskers on thermal cycling.

��

��3. 4 ��

��

�6 ^� ^�6 ^�1�

�� 5.3�10 deg ¹�� 6.2�10 deg

�6 ^�1 1

�� 2.6�10 deg �� ^��

��

��. ��

�Tmax = 673K ��

��

2CVVGTUQP�9)�6C[C�/��A2124

��15��

��

293K�673K ��

��1000 ��5.5��

Fig. 3 TEM photographs of the composites.

Fig. 4 ��Fig. 3 ��

��Fig. 5 ��

��.

��⁶^��A2124 �A6061 ��

Fig. 4 The HR-TEM diffraction pattern from

��

the black area in Fig. 3.

��

(5)

�

Fig. 5 The HR-TEM diffraction pattern from

the white area in Fig. 3.

Fig. 4 ��, ��

��Fig. 5 ��

��

��, ��

��nm ��

��

��, ��

��

��. ��

��

�, ��

��

ANSYS ��, ��273K ��573K �

��

��Fig. 6 �Fig. 7 ��8

��1 ��

��

Fig. 6 ��

Fig. 6 The equivalent strain of the composites heated from 273K to 573K.

��

� Fig. 7 ��

��773MPa ��

�� 275MPa ��

�, �� 573��

��

��, ��

��

Fig. 7 The equivalent stress of the composites heated from 273K to 573K.

��

�� A6061 ��

��

(6)

��

��, ��

(1)��

��

(2)��573K, 673K ��, �1000 �

��, 773K ��

��

(3)��

��

(4)��

��

� � � � � � �

(5)��

��

�

��8QN�0Q�

��

�� 0%+2+��

��

2CVVGTUQP�9�)�CPF�6C[C� /�2TQE�+%%/8�GFKVGF�D[�9�%�

*CTTKICP�,T�GVCN6/5�QH�#+/'��

Thermal Strain of Thermally Cycled Alminum Alloy Composites ������������������������������

����

������������������������������

� � � � * � � � � � � �

Thermal Strain of Thermally Cycled Alminum Alloy Composites

���� � �

�������

���� ������������������

���� ����������������

���� �����������������

���� ������������������

��������

���� ������������������

� � � � � ����������

�������������

�����������������

��������������

�����������������

Fig. 4 The HR-TEM diffraction pattern from

the black area in Fig. 3.

Fig. 5 The HR-TEM diffraction pattern from

the white area in Fig. 3.

���� ���������������

�� � ��

�����

Thermal Strain of Thermally Cycled Alminum Alloy Composites ��

��

��

��

��

��

��

��

��

��

��

� � � � � ��

��

��

��

��

��

��

��