CREATE TABLE table_4182 ("Outcome" TEXT, "Year" FLOAT, "Championship" TEXT, "Surface" TEXT, "Partner" TEXT, "Opponents" TEXT, "Score" TEXT)

On what surface was the Australian Open (6) played on?
SELECT "Surface" FROM table_4182 WHERE "Championship" = 'Australian Open (6)'
SELECT "Surface" FROM "table_4182" WHERE "Championship" = 'Australian Open (6)'