Disodli awyrennau domestig mawr gydaaloi titaniwm
Yn 2006, cymeradwyodd y Cyngor Gwladol sefydlu Pwyllgor arddangos cynllun awyrennau mawr. Cao Chunxiao yw'r unig aelod sy'n ymwneud ag ymchwil deunydd hedfan. Ar ôl lansio'r prosiect, gwasanaethodd Cao Chunxiao fel aelod o'r pwyllgor cynghori arbenigol a theithiodd ledled y wlad. Mae'r prosiect awyrennau mawr yn cwmpasu awyrennau sifil a milwrol, a'r cod awyrennau sifil yw C919.
The less weight an airplane has, the better. The weight of the airplane itself is a percentage of its total take-off weight, which is called the "structural weight coefficient of the airplane". In the past 70 years, no aircraft has had a structural weight factor of less than 27 percent , which is due to the performance of large components and the manufacturing capacity of large components. Titanium material becomes the key. Aloi titaniwmgall deunyddiau a thechnoleg ffugio leihau pwysau strwythurol awyrennau a gwella ei gystadleurwydd.
Today, the more economically demanding C919 uses 8 percent titanium, comparable to 7.5 percent of the Boeing 777 in the U.S. Large aircraft can not be manufactured without large forgings which require high technology. In the column "Academician's Introduction", Cao Chunxiao shows titaniwm forging joint for C919, named TC4, weighing 600 kg. To make similar forgings, China has built the world's largest 80,000-ton hydraulic press.
In November 2015, C919 with China's independent intellectual property rights was officially unveiled worldwide in Shanghai. Cao Chunxiao was thrilled at the scene and his dream of more than forty years came true at last.
Ar Fai 5, 2017, gwnaeth yr awyren C919 ei hediad llwyddiannus cyntaf yn Shanghai. Ym mis Mawrth 2021, cymerodd C919 y gorchymyn cyntaf. Erbyn dechrau 2022, roedd yr C919 wedi cymryd 815 o orchmynion.
