Radiation-induced damage and strain in AlxGai-xAs (x=5 to 1) were investigated by measurements of the lattice parameter using x-ray diffraction. Irradiations employed MeV C, Ar and Au ion beams with a substrate temperature of 80 K. For samples with high Al content, the out-of-plane lattice parameter increased with fluence at low doses, saturated, and then decreased to nearly its original value. The in-plane lattice parameter did not change, throughout. These results were independent of the irradiation particle when scaled by damage energy. For the Al.5Ga.5As samples, however, the out-of-plane lattice parameter increased monotonically with dose to large strains until the layer amorpnized. Selected samples were examined by high resolution and conventional transmission electron microscopy (TEM). Channeling Rutherford backscattering spectrometry (CRBS) was also employed to monitor the buildup of damage in many samples. Recovery of the lattice parameter during subsequent thermal annealing was also investigated.