Ben Xu in Lab (IMAGE) University of Houston Caption Photo 1: University of Houston Professor Ben Xu operating a planetary ball mill machine to mix metal powders for additive manufacturing machine. Credit Please give credit to the University of Houston Usage Restrictions Please give credit to the University of Houston License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.