Thermally conductive silicone grease composition

A thermally conductive silicone grease composition comprising the following components:

• (A) 100 parts by mass of an organopolysiloxane which is liquid at 25° C. and is represented by the following average compositional formula:
• R1aSiO(4-a)/2
• where, R1 is a monovalent hydrocarbon group and “a” is a number ranging from 1.8 to 2.2, wherein component (A) comprises an organopolysiloxane (A1) that is free of aryl groups and organopolysiloxane (A2) that contains aryl groups, and wherein the content of constituent (A2) in component (A) is in the range of 10 to 50 mass %;
• (B) 800 to 6,000 parts by mass of a thermally conductive filler composed of constituents (B1) to (B3) given below, wherein:
• constituent (B1) is spherical aluminum oxide powder with an average particle diameter ranging from 15 to 55 μm, in an amount of 40 to 80 mass % of component (B);
• constituent (B2) is spherical aluminum oxide powder with an average particle diameter ranging from 2 to 10 μm, in an amount of 5 to 45 mass % of component (B);
• constituent (B3) is aluminum oxide powder with an average particle diameter not exceeding 1 μm, in an amount of 5 to 25 mass % of component (B);
• and
• (C) 10 to 300 parts by mass of an organopolysiloxane represented by the following general formula:
• where, R1 designates same or different monovalent hydrocarbon groups;
• X designates identical or different monovalent hydrocarbon groups or an alkoxysilyl-containing group of the following general formula:
• —R2—SiR1b(OR3)(3-b)
• where, R1 is the same as defined above, R2 is an oxygen atom or an alkylene group, R3 is an alkyl group;
• and “b” is an integer from 0 to 2;
• and “m” and “n” are integers equal to or greater than 0.